Y o u r V a l u e P a r t n e r Weholite Manual © Copyright Marley Pipe Systems (Pty) Ltd 2014 www.marleypipesystems.co.za About Us Marley Pipe Systems have been manufacturing SABS approved products since consumer protection was first mandated in the industry. In keeping with international trends, Marley is a market leader in converting to lead free materials. Marley’s commitment to quality and safety has all pipes and components manufactured in an ISO9001 accredited facility. 01 About Us Your TRUE Value Partner Marley Pipe Systems is the leading manufacturer and distributor of plastic pipes and fittings for reticulation systems, serving the key market segments of the plumbing and building industries as well as the infrastructure sector throughout sub-Saharan Africa. We at Marley Pipe Systems are dedicated to serving our clients with quality solutions, expertise, dedication, passion and integrity and, as an Aliaxis company, we bring solutions, new technology and expertise on a global level to the local market, ensuring our clients are always ahead of the times. Add to this a commitment to providing only the best in technical support, expertise, integrity and service delivery, and you've got a true Value Partner in Marley Pipe Systems. Today, the Marley Pipe Systems team consists of over 880 people with the manufacture of all pipe and fittings taking place at Nigel and Rosslyn in Gauteng. Vision Values To become the preferred and most respected distributor and manufacturer of quality plastic pipe systems for the Building, Civils, Mining, Irrigation and Industrial markets in sub-Saharan Africa. Purpose To grow responsibly towards becoming a truly regional (sub-Saharan Africa) player represented in major centres, manufacturing fast moving product ranges at local plants across the region as well as providing a wholesale offering on group and externally produced products. Y o u r V a l u e • Integrity • Honesty • Passion • Reliability • Trust • Accountability • Compassion • Professionalism • Respect • Commitment • Excellence • Ethics P a r t n e r www.marleypipesystems.co.za - - Introduction Introduction to Weholite Polyethylene is recognised by clients and engineering consultants alike as the ideal pipe material for many pressure and non-pressure applications – from water distribution to gravity sewers, rehabilitation projects and manholes to marine pipeline applications. Recognising clients’ needs for large diameter, lightweight, low-pressure pipes and fittings, Marley now offers Weholite, a pipe constructed by a patented structured wall process that allows the manufacture of diameters from 280mmm up to 3500mm. Weholite is manufactured in Finland, Sweden, Poland, South Africa, the United Kingdom, Canada, Malaysia, Oman, Iceland, Italy, Chile, Japan and Thailand and is steadily gaining ever wider acceptance in other countries worldwide. 03 Weholite Applications Landfill Drainage Mine Drainage 1500mm Weholite shaft with stepladder and Solid-Wall HDPE piping. Landfill drainage site, Gauteng. 300mm Weholite pipe perforated for mining drainage pipe. Attenuation Application Fittings/Specials Stormwater attenuation application. Marine Pipeline Application Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request 04 Weholite Applications Weholite structured wall HDPE pipe provides all the raw material advantages of equivalent polyethylene solid-wall pipes, but with substantial savings in weight, thus combining greater ease of installation with increased cost effectiveness. Weholite pipe represents the latest advances in both material and manufacturing technology. Its unique structure offers a range of pipe sizes and ring stiffnesses, depending on customer requirements. The combination of raw material properties and product technology provides a lightweight engineered pipe with superior capacity for various municipal, industrial, road-building, rehabilitation and marine pipeline applications. Sewer Pipelines Pipe Rehabilitation 1250mm outfall sewer. Blackburn, Durban. Rehabilitation of a corrugated galvanised pipe. Stormwater Culverts 3m x 700mm stormwater pipe lengths being laid in Cullinan. 05 Product Range & Dimensions SWP (Structured Wall Pipe) Weholite Marley manufactures Weholite pipe under licence from Uponor Infra (formerly KWH Pipe). Weholite pipes are manufactured in accordance with Uponor Infra and Marley internal standards which are in accordance with EN 13476 and SANS 21138 and form part of an SABS ISO 9001:2008 quality management system. Regular inspections and audits are carried out by the local inspection authority. The pipe design allows for a minimum design life of 50 years under specified design and installation parameters. The material selection process is the same as that used for pressure pipe applications. Research has shown that the service life of Weholite will be at least 50% greater than concrete, and in corrosive applications, at least 100% greater than concrete. Weholite structured wall HDPE pipes are supplied as follows: Stormwater Sewer Sandtight male-female coupling, no seal = OGEE joint “Watertight” socket and seal for DN560 pipes are welded in situ Threaded joint* D≥1200mm pipes Standard lengths 3m, 6m, 12m (24m pipes may also be specified) Standard lengths 6m, 12m *Stiffness design is according to ISO 9969 Weholite pipe sizes: Pipe CD/ID (mm) Max Pipe OD (mm) 2kN/m2 Max Pipe OD (mm) 4kN/mm2 8kN/m2 Max Socket OD (mm) 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 1250 1500 1800 318 334 385 439 484 555 616 665 765 840 878 980 1105 1177 1305 1350 1685 2022 318 341 404 454 505 565 638 677 790 840 903 1016 1128 1254 1354 1400 1685 2022 390 415 476 526 576 636 708 747 865 919 980 *N/A *N/A *N/A *N/A *N/A *N/A *N/A Sizes larger than 1800mm upon request Dimensions are indicative and may change from time to time *For watertight joint, pipes need to be extruder welded *A subject to availability 06 Product Range & Dimensions Stormwater 280-500mm Sewer Pipe Female socket, sandtight (geotextile may be required) Socket with seal – watertight Threaded Joints Threaded Joint Details: (Sandtight) Welded for watertightness Nominal Size DN/ID B A B ≥ 0,5 Profile Height ≤ 0,75 Profile Height DN<500 500 560 600 700 750 800 1000 1100 1200 (A) Min Thread Length mm 100 130 146 155 170 175 180 200 200 240 07 Double Sockets NS = di mm De mm L mm M mm Do mm 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 315 338 400 450 505 560 618 675 788 844 900 1013 1125 1238 1350 628 684 740 796 830 916 960 1042 1166 1180 1200 1300 1400 1400 1400 199 206 220 248 278 308 240 371 433 442 450 500 550 550 550 364 388 438 488 550 602 660 705 830 900 944 1050 1170 1280 1395 Flange Joints Double-socketed standard fitting Joint DN mm 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 Weholite De mm 315 338 400 450 505 580 618 675 788 844 900 1013 1125 1240 1360 NS=di mm 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 PE Pipe De mm 280 280 355 400 450 500 560 360 710 710 800 900 1000 1000 1200 L mm 377 377 377 385 380 379 390 390 400 410 415 430 438 440 460 Flange D mm 412 412 505 565 670 670 780 835 895 955 1015 1115 1230 1343 1455 b mm 22 22 28 32 36 38 50 40 50 50 56 56 60 60 60 k mm 350 350 376 430 473 515 691 703 725 770 815 915 1015 1115 1215 Bolts pcs x size Bolts Torque Nm 12XM20 12xM20 16xM20 16XM24 20XM24 20XM24 20XM27 20XM27 24XM27 24XM27 24XM30 28XM30 28XM33 28XM33 32XM36 34 38 45 60 65 70 86 88 90 95 100 115 130 138 141 Dimensions are calculated values and may vary from the finished product Flange drillings are dimensioned according to customers’ requirements 08 Stub End h mm 34 34 40 44 44 44 50 56 56 60 70 86 88 96 100 d4 mm 320 320 430 482 485 485 685 685 805 853 900 1005 1110 1220 1330 Bends Bends 1° - 30° Bends 31° - 60° Bends 61° - 90° Double-socketed Standard Fittings NS=Di mm de mm R = 1,0 x NS mm 30° Z mm Ze mm 45° Z mm Ze mm 60° Z mm Ze mm 90° Z mm Ze mm 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 1250 1500 1800 315 338 400 450 505 560 618 675 788 844 900 1013 1125 1240 1350 1575 1680 2016 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 1250 1500 1800 267 312 357 402 450 499 550 602 703 730 758 858 935 1049 1012 911 975 1170 81 126 173 157 175 191 191 231 270 379 308 487 385 678 464 540 604 799 352 412 472 532 590 661 730 797 931 980 1018 1118 1260 1344 1402 1365 1460 1752 166 226 252 284 315 353 371 426 498 629 468 747 710 973 852 994 1089 1381 331 361 421 541 557 572 692 811 947 992 1037 1160 1283 1357 1430 1398 1495 1794 235 244 261 296 331 365 403 440 514 551 587 660 733 807 880 930 1100 1300 473 547 621 695 750 865 900 1041 1215 1250 1344 1443 1667 1709 1891 1936 2073 2488 309 355 401 447 500 557 620 670 782 820 894 1000 1117 1200 1341 1400 1700 2000 Dimensions are calculated values and may vary from the finished product. Tolerances for pipe lengths Z and Ze are ±50mm (+23°C). Other angles and bend radii can be supplied on request. Dimensions above 1800mm will be designed individually to meet customer requirements, transport possibilities, etc. 09 Equal Tees Double-socketed Standard Fittings NS 1 mm de 1 mm NS 2 mm de 2 mm Z1 mm Z2 mm Z 2e mm Z3 mm Z 3e mm 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 1250 1500 1800 315 338 400 450 505 560 618 675 788 844 900 1013 1125 1238 1350 1575 1680 2016 280 300 350 400 450 500 560 600 700 750 800 900 1000 1100 1200 1250 1500 1800 315 338 400 450 505 560 618 675 788 844 900 1013 1125 1238 1350 1575 1680 2016 365 424 483 542 600 674 750 812 947 1000 1038 1150 1284 1362 1431 1400 1500 1800 365 424 483 542 600 674 750 812 947 1000 1038 1150 1284 1362 1431 1400 1500 1800 226 238 263 294 325 366 391 441 576 629 667 779 913 991 1060 1029 1129 1429 365 424 483 542 600 674 750 812 947 1000 1038 1150 1284 1362 1431 1400 1500 1800 226 238 263 294 325 366 391 441 576 629 667 779 913 991 1060 1029 1129 1429 For branches (NS 2<NS 1), lengths Z3 and Z3e are equal to above. Dimensions are calculated values and may vary from the finished product. Tolerances for pipe lengths Z and Ze are ±50mm (+23°C). Dimensions above 1800mm will be designed individually to meet customer requirements, transport possibilities, etc. 10 Manholes The Weholite manhole system provides solutions for all sewerage and stormwater systems. Manholes are normally prefabricated. Pipe connections can be manufactured to suit any standard sewer pipe. The inclinations and angles of the connections can be set as required. Standard manhole covers will be selected according to application or traffic loads. If required, ladders can be fitted inside the manhole. Manholes for high water table are designed accordingly. Reinforced concrete base to be designed to counter buoyancy and to anchor HDPE puddle on manhole. Manholes Lateral Manholes Reducing Manholes Straight or Bends SHAFT SHAFT SHAFT HDPE STEPS HDPE STEPS HDPE STEPS Xo Xo Xo Xo Xo BENCHING BENCHING BENCHING Z1 di(ID) I di( Z1 Z1 D) Xo Z2 Z2 Di(ID) Di(ID) Di(ID) X = 15° Z1 = 1,5m Di(ID) = 1200mm di(ID) = 497mm X = 15° Z1 = 1,5m Di(ID) = 1200mm di(ID) = 497mm X = 15° Z1 = Z2 = 1,5m Di(ID) = 1200mm Socket and seal included all round Socket and seal included all round Socket and seal included all round Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request *Drawings indicative and can or may be changed 11 Designing with Weholite Inherent Properties of Weholite Structured Wall Pipe High Density Polyethylene as a Material for Pipe Construction HDPE has long been considered ideal for sewer applications. Owing to the economic advantages of structured wall (or profiled-wall) technology, Weholite HDPE pipe can now be used as an economic alternative to traditional materials such as vitrified clay, reinforced concrete (R/C), fibre cement (F/C) pipes and corrugated galvanised steel. Below, typical values can be used to perform structural design as per EN 1295-1. Typical physical properties of Weholite pipe material Unit kg/m3 N/mm2 Mm/mM.k. W/m°C Corrosion and Chemical Attack Traditional pipe (concrete) materials may suffer from bacterial or chemical attack in a corrosive environment (such as that encountered in sewer and effluent lines). HDPE is highly resistant to such attacks, making Weholite an ideal alternative for long pipe service life. For all practical purposes, PE is chemically inert in normal use. Electrolytic and galvanic corrosion are therefore eliminated. More information on the chemical behaviour of PE is given in ISO 10358. 12 Value >930 1000 13 x 10-5 0.3 – 0.4 0.4 Standard ISO 1183 ISO 527 Abrasion Asbestos cement pipe 3,0 Fibre glass reinforced pipe 2,5 Abrasion (mm) Property Density E-modulus short term Linear expansion coefficient Thermal conductivity Poisson’s ratio 2,0 1,5 Concrete pipe Clay Pipe 1,0 PVC 0,5 0 HDPE 200 000 400 000 600 000 Load cycles N In the Darmstadt abrasion test (DIN 19534, Part 2), samples of commonly used pipe materials were filled with a mixture of sand and water and subjected to a specified number of rocking cycles. The amount of abraded material was measured at regular intervals. The result proved the very high abrasion resistance of polyethylene pipe material – 400 000 load cycles resulted in 0,3mm abrasion for PE pipes. Abrasion in fibre-reinforced and concrete pipes was 6-8 times higher. Designing with Weholite Inherent Properties of Weholite Structured Wall Pipe UV Stability and Temperature Range In accordance with international material standards, the HDPE grades used in Weholite production may be UV stabilised by the addition of carbon black, making Weholite almost impervious to UV attack. The maximum permissible temperature of the medium transported is: +80°C (short term) and +45°C (long term) Product Advantages Weholite has an effective double wall, ensuring system integrity should the pipe be damaged either externally or internally. Scale and Sediment Build-up HDPE does not readily bond with or adhere to other materials. This ensures that build-up does not occur, and long-term flow characteristics are not affected when Weholite is specified. 12m lengths offer a greatly reduced joint frequency, which minimises the possibility of leakage or ingress of groundwater (which can lead to excessive loading of downstream treatment plants). Weholite offers superior crack resistance due to the ability of the material to “unload” excessive stress on to the surrounding backfill. Such stresses (often caused by soil movement) could result in failure of pipelines assembled with rigid materials such as concrete and fibre cement. Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request 13 Weholite High Density Polyethylene (HDPE) Resin *Technical Specifications of HDPE Raw Material Physical Properties Density Melt Flow Index (190C/21,6kg) Melt Flow Index (190C/5kg) Vicat Softening Point (5kg) Crystalline Melting Range Viscosity Number Mechanical Properties Shore D Hardness Tensile Yield Ultimate Tensile Strength Ultimate Elongation Elastic Modulus Flexural Strength (3.5% Deflection) Notched Impact (Charpy) can 23°C Notched Impact (Charpy) can -30°C Thermal Stability (OIT1, 210°C) Carbon Black Content ISO 1183 ISO 1133 ISO 1133 ISO 306 ISO 3146-85 ISO 1628 0.958 9.0 0.23 67 130-133 390 ISO 868 IS0 527 IS0527 ISO 527 ISO 527 ISO 178 ISO179 ISO 179 ISO 10837 ASTM D 1603 61 24 35 >600 900-1000 19 20 6 ≥20 ≥2 g/cm3 g/10 min g/10 min °C °C cm3/g Mpa Mpa % Mpa Mpa KJ/m2 KJ/m2 Min % 1) OIT: oxidation induction time * Alternative materials may be used from time to time Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request Weholite Flow Calculation Hydraulic Design Colebrook-White Formula ʋ = kinematic viscosity (m2/s) d = internal diameter (m) g = acceleration due to gravity (9.81m/s2) u = velocity (m/s) l = hydraulic gradient (‰) k = roughness coefficient (m), Weholite pipe 0.03mm 14 Hydraulics Owing to the low friction coefficient of HDPE, the coefficient of friction of Weholite pipes is relatively low. COLEBROOK-WHITE MANNING HAZEN WILLIAMS k = 0.03mm m = 0.01 C = 135 These figures are generally below those obtained with new reinforced concrete pipe, and no adjustment (to allow for corrosion, etc.) is required with Weholite pipe designs (20% - 30% lower than used for concrete). Designing with Weholite Proportional Velocity and Flow Rate in Partially Filled Pipes Fil l i ng l e ve l % 100 Flow volume Area Velocity Hydraulic Radius 80 Diagram showing the change of water flow volume, filled area, flow velocity and hydraulic radius as a function of the filling level in the pipe. (The 10 Q curve illustrates an enlargement of the Q curve between 0% and 12% on the horizontal axis) Q A u R 60 Q A 40 U 20 R 10 Q 0 20 40 60 80 100 1 20 C h a n g e o f p ro p e rt y % Example of the Change in Flow Volume and Velocity Gradient Filling NS=400 NS=800 NS=1200 ‰ 1 Level 100% 50% 25% u m/s 0.60 0.51 0.33 Q l/s 25 34 10 u m/s 0.93 0.79 0.51 Q l/s 465 219 61 u m/s 1.19 1.01 0.66 Q l/s 1348 607 175 100% 50% 25% 1.36 1.15 0.75 170 77 27 2.09 1.78 1.15 1052 473 168 2.69 2.29 1.48 3041 1369 487 100% 50% 25% 1.92 1.64 1.60 242 109 31 2.97 2.52 1.63 1492 671 194 3.81 3.24 2.10 4310 1940 560 5 10 15 Designing with Weholite Discharge (ℓ/s) for Pipes with Full Flow Roughness coefficient value for Weholite pipe 0.03mm Roughness coefficient value of 0.25mm for the pipe system (diagram) Kinematic viscosity of water at +10°C Gradient ‰ Flow l/s Gradient ‰ Flow l/s • • • Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request 16 Loads on Buried Pipes Weholite Loads on Buried Pipes Flexibility in Buried Pipelines In the case of low-pressure or thin-walled pipes, it is frequently not the internal pressure but the external pressure which dictates the pipe wall stiffness. A pipe is less resistant to external loads than to internal pressure, as the pipe wall acts in a different way. Whereas internal pressure exerts pure tension on the pipe walls, external loads may cause circumferential or longitudinal bending, arching and even buckling. A flexible pipe is by definition a pipe which will deflect when subjected to external loads (traffic, ground water changes, soil settlement, etc.) as opposed to a rigid pipe, which carries all external loads by itself. The degree of deflection of a flexible pipe will depend on the pipe stiffness, support from the surrounding soil and external loads. External loads are not symmetrical; the vertical loading due to soil pressure or superimposed loads is greater than the lateral soil pressure. It is this differential loading which causes bending of the pipe wall. There are several methods for calculating the deflection in buried flexible pipelines. Most of them are based on the so-called Spangler Formula: Deflection (%) = vertical load on the pipe pipe stiffness + soil stiffness Possible loads on a pipe Pipelines are typically subject to: a. b. c. Vertical soil pressure Superimposed live loads due to vehicles Crushing or bending by heaving or moving soils Causes of pipe failure Excessive loads may result in failure due to: a. b. c. d. e. f. g. Crushing or compression of the pipe wall Tensile failure Bending of the pipe wall Longitudinal bending Excessive deflection Buckling A combination of any of the above After installation, further gradual compaction of the surrounding soil takes place due to external loading and soil settlement. Experience shows that the maximum deflection will be achieved within 1-3 years after installation, depending on backfill material, the quality of backfill compaction work and on external loads. The maximum allowable deflection is 8-10% (pipe and welded joints only) and 3-5% (joints). A flexible pipe absorbs external loads and deforms to a certain extent. A rigid pipe, on the other hand, by definition cannot deform. When external loads increase sufficiently, the rigid pipe will finally crack, after which it starts to behave like a flexible pipe. Pipes installed underground react to soil settlement along the length of the pipeline. Loads/deflections vary from place to place. Flexible pipes react to additional settlement/loads by bending, while rigid pipes react by angular deformation in the joints. 17 Loads on Buried Pipes For alternative soil types, refer to table below. For reference: In accordance with pr EN 1046, A 127 and WG 14, the following soil types and groups have been proposed by G. Leonhardt 1998/02/02 based upon recommendations given in British Standard BS 5930 and German Standard DIN 18196: Group 1: poorly graded gravel, single sized gravel Group 2: granular soils, such as well-graded gravel, gravel-sand mixture, single sized sand, well-graded sand, poorly graded sand-gravel mixture Group 3: mixed grained soils with low fine fraction and some cohesion such as silty gravel-sand mixture, clay-like gravel-sand mixture, silty sand, clay-like sand Group 4: mixed grained soils with high fine fraction moderate cohesion such as very silty respectively clay-like gravel-sand mixture, very silty respectively clay-like sand, silt of low plasticity Group 5: fine grained cohesive soils such as inorganic silts respectively clay, grained soils with admixture of humus or chalk, organic silt, organic clay Initial Average Pipe Deflection % for Well Performed Procedure at Depth of Cover 6m % Deformation Soil Group 1 2 3 4 5 4 kN/m2 2 kN/m2 8 kN/m2 Short Term Short Term Max Short Term Short Term Max Short Term Short Term Max Ave 1.7 2.0 2.4 3.2 3.6 Max 2.6 3.0 3.6 4.8 5.4 Long 3.4 4.0 4.8 6.4 7.2 Ave 1.6 1.8 2.2 2,9 3.2 Max 2.4 2.7 3.3 4.4 4.8 Long 3.2 3.6 4.4 5.8 6.4 Ave 1.4 1.6 1.9 2.4 2.6 Max 2.1 2.4 2.9 3.6 3.9 Long 2.8 3.2 3.8 4.8 5.2 If a structural design is required, e.g. in cases where no other information exists, then a method as defined in EN 1295-1 should be used. A Marley representative can also be contacted to assist through manipulation of variables in a finite element design software package. 18 Design The design requirements of Weholite allow the engineer an optimum combination of pipe strength and flexibility, and installation savings are normally easily achieved compared with ridgid materials. Loading / Deflection Under loading, flexible pipes deflect, and Weholite (which is viscoelastic) reacts similarly. Deflection is vital, as it optimises the pipe/soil interaction and ensures a crack-free system. Rigid materials cannot interact with soils and have to bear loads entirely, irrespective of soil stiffness. It is important to contain deflection. Three standard ring stiffness classes exist; 2 kN/m2, 4 kN/m2, 8 kN/m2 are applied as follows. Stiffness design conforms to ISO 9969: Ring stiffness, Validity of the Design Graph The design graph is valid under the following conditions: • • • • • • RS ISO = EoI D3m Where Eo = 1000 N/mm2 I is calculated from the geometry of the true profiled wall Dm = Mean diameter of pipe Design graph for pipe selection Based on the study (TEPPFA; 1999; Design of Buried Thermoplastics Pipes), several design approaches can be proposed. For thermoplastic pipes possessing huge strainability, designs can be kept simple. It has also been shown that more effort should be put into the installation of the pipe, but not more than for rigid pipes. An important observation is also that flexible pipes follow the soil settlement, and behaviour is managed by this. Load is therefore not an issue for flexible pipes in well installed conditions. Therefore, based on the results of this work, the design approach using simple graphs is strongly recommended. In the design, graphs-areas are given for each installation group. The lower boundary of each group represents the average deflection expected and upper boundary the maximum. The design graph contains three installation groups. The add factors are fully linked to the type of installation. The add factors or consolidation factors (Cf) have to be added to the value for the initial deflection which can be obtained from the graph. • Depth between 0.8m and 6m, both included. Depth/diameter ratio at least above 2.0 Designers first need to establish permissible deflections, average and maximum (national requirements, product standards, etc.). Pipes fulfil the requirements listed in the Weholite internal standard and international standards. Installation categories “well”, “moderate” and “none” reflect the workmanship on which the designer can rely. Sheet piles are removed before compaction. If the sheet piles are removed after compaction, the “well” or “moderate” compaction level will be reduced to the “none” compaction level. For the deflection mentioned in the graph, the strain will be far below the design limit and need not be considered in the design. Installation Types As per ISO TC 138/sc1 and or ENTS 13476-3 Well Well Primary backfill: granular type Layer 30cm + compaction Final backfill: soil of any type + compaction Compaction: >94% mod. Proctor Cf = 1,0 Moderate Moderate Primary backfill: granular type Layer 50cm + compaction Final backfill: soil of any type + compaction Compaction: 87 - 94% mod. Proctor Cf = 2,0 None None Backfill: granular /cohesive type Layers: without compaction Compaction: <87% mod. Proctor Cf granular Cf cohesive = 3,0 = 4,0 19 Buckling Weholite Design Methodology • • Ensure that Weholite pipes and variables comply with variables referred to in the leaflet on Pipelaying (Validity of the Design Graph). Determine national long-term maximum allowable circumferencial deflection % (Either pipe or joint will prevail). Example: During the construction phase – before side fill is compacted and soil stiffness is attained – the pipe is subjected to full loading without support of the side fill. A buckling check is done according to graphs below. Buckling loads should never exceed 50% of the predicted buckling strength (i.e. a safety factor of 2 against buckling must be observed). For a firmly buried pipe, the buckling pressure Pbs can be determined as: Pbs = 5,63 √ SN•E’t Pipe and extrusion welded joints / Threaded joints 2 kN/m2 4 & 8 kN/m2 Short Term Long Term 5% 8% 8% 10% Joints with or without rubber meal 2 kN/m2 4 & 8 kN/m2 • • • Short Term Long Term 2% 4% 3% 5% Determine installation type. Determine consolidation factor (Cf) in accordance with installation type. Determine maximum short-term allowable deflection. Example: where: Pbs = Buckling pressure (MPa) SN = Ring stiffness (MPa) E’t = Tangent modulus of the soil (MPa) n = Safety factor (normally ≥2) The value is theoretical limit. Under normal circumstances, the safety factor against radial buckling should never be less than 2. Pperm = Pbs n Tangent Modulus for Friction Soils E’t (Mpa) 3,0 90 r octo . pr od %m 2,0 3,0 2,0 85 % 80 % 1,0 1 2 3 90 1,0 75 % 0 (δ/d) final = (δ/d) instantaneous + Cf E’t (Mpa) Ground water table below pipe 4 5 6 7 H (m) Filling Height %m od. ctor pro 85 % 80 % 75 % 0 1 2 3 4 Filling Height 5 6 7 H (m) Thus for a joint 2 kN/m2 pipe 3% long-term maximum allowable deflection for well performed installation is as follows: Calculation example • Groundwater table below pipe • Filling height = 3m • Degree of compaction = 90% mod. Proctor • Ring stiffness of a pipe = 4 kN/m2 = 0,004 Mpa f 3% - 1% = 2% from a table E’t = 2,5 MPa Or maximum allowable for moderate performed installation Pbs = 5,63 √( 0.004 * 2.5) = 0.563 MPa Thus 3% - 2% = 1% Pperm = 0,563/2 = 0,28 MPa Thus (δ/d) instantaneous = (δ/d) final - Cf Both conform to maximum stated in “Joints with or without rubber seal”. Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request 20 Weholite Pipe Handling Handling and Storage Instructions Correct loading and unloading Relevant national or local regulations must be observed. It is important that loading, unloading and handling be performed safely to avoid damage to property or equipment. As loading and handling can be a hazard to persons in the unloading area, unauthorised persons should be kept at a safe distance while unloading. General Weholite pipes are sturdy and lightweight, which makes them easy to use. Unfortunately, these properties also increase the temptation to abuse the pipe. Proper handling is required to minimise the risk of damage. Pipes must be handled with sufficient care. They can be damaged if dropped or thrown about. Pipes or bundles of pipes must never be dragged – the pipe surface may be weakened by scratches. When transporting and storing pipes, care must be taken not to permanently deform the pipes. Socketed pipes in particular must be stored in such a way that their sockets are not subjected to loading that will cause deformation. Adequate level space must be reserved for unloading. Secure the truck on level ground as well. The unloading equipment must be capable of safely lifting and moving the pipe, fittings, fabrications, etc. Off-loading may be done by means of skid timber and strap slings or with mechanical lifting devices. However, lifting chains, ropes or hooks may not be used, as these may result in permanent damage to the product. Lifting points must be well spread and evenly spaced. Transport and unloading Pipes should be transported on flat transport beds without sharp edges or other projections that might damage the pipes. Movement or rubbing of pipes during transport must be prevented, for instance by strapping the pipes down. When pipes of different sizes are transported, the heaviest lengths are loaded underneath. If the pipes are transported nested inside one another, the smaller pipes are removed first and piled separately. Upon arrival at the site, the pipe shipments are visually inspected and checked against the packing list for correctness in size, stiffness and quantity. The pipes must also be inspected for damage which may have occurred during handling and/or transport. Obvious damage such as cuts, abrasions, scrapes, tears and punctures must be carefully inspected and noted. Any damage, missing items, etc. must be noted on the bill of loading and signed by the customer and the driver. Shipping problems such as the above should be reported to the supplier immediately. Single Pipes When lifting single pipes, use pliable straps or slings. Do not use steel cables or chains to lift or transport the pipe. Pipe sections can be lifted with only one support point, but especially for larger diameters it is recommended to use two support points to make the pipe easier to control. Do not lift the pipes by passing a rope through the centre of the pipe end to end. 21 Weholite Pipe Handling Nested Pipes Preferred lifting technique Always lift the nested bundle by at least two pliable straps. Ensure that the lifting slings have sufficient capacity for the bundle weight. Stacking of nested pipes is not advised unless otherwise specified. Storage Inspect all materials carefully upon arrival on site and note and report any defects immediately. All pipe stacks must be made on firm, flat ground that can support the weight of the pipes and lifting equipment. For safety and convenience of handling, the stack height for pipes is limited to five units or not more than 2.8m. Stacks must be adequately wedged to prevent movement. Normal stacking of plain ended pipes Pipes must be stored on intermediate supports spaced not more than 2m apart. The support width must be greater than the profile width of the pipe size in question, but not less than 100mm. Pipes with integral sockets must be stacked with the sockets at alternate ends, or at least without loading the sockets. Pipes with z-cut ends must be stored with the z-cut oriented in the same position (at 12 o’clock). The maximum storage height for pipe stacks is 2.8m overall. Besides protecting all material adequately against theft, vandalism, accidental damage or contamination, also keep pipes and fittings away from sources of heat if at all possible. If the pipes are to be stored for long periods, they must be protected against excessive heat; storage at high temperatures for prolonged periods can cause excessive deformation that may affect installation. To avoid this risk, the following precautions are recommended: a. Shield the stacks against continuous and direct sunlight and allow free passage of air around the pipes; b. Store the fittings in boxes, sacks or shading manufactured so as to permit free passage of air; c. Protect elastomer sealing rings against direct sunlight. 22 Stacking of socketed pipes Weholite Choice of Stiffness Weholite Choice of Stiffness (SN) Series General Weholite pipes are flexible pipes. A flexible pipe installed in the ground deflects during installation, because of the force exerted on it, as well as after installation, because of the further settlement of the soil. The amount of deflection reached after installation depends to a great extent on the quality of installation and to a lesser extent on the pipe stiffness. The increase in the pipe deflection after installation depends on the amount the soil can settle after installation. When the soil around the installed pipe is well compacted, any increase in pipe deflection will be very limited. If the soil compaction ratio is low, pipe deflection will increase during settlement. Traffic load does not affect pipe deflection other than increasing the rate of settlement of the soil. Procedure for Pipes Prescribing a specific level of workmanship is the surest way of controlling pipe deflection. It has been proven that this parameter has by far the greatest influence on deflection. If, however, the installation procedure is fixed, then the choice of stiffness class (SN) can be made on the basis of one of the following: • • • When reference situations exist: Has the same class of pipe used under similar or more severe conditions been found acceptable? Based on the Design Graph, see leaflets on Loads on Buried Pipes and Pipelaying Based on structural design, see leaflet on Pipelaying Procedure for Fittings Generally, fitting in accordance with this standard should have the same stiffness class as the pipes to which they are connected. Fittings in accordance with EN 1401-1, 1852-1 and 12666-1 can be used in combination with pipes according to this standard. Because these fittings are classified by their wall thickness, their actual stiffness is higher than that of a pipe with the same wall thickness. Such fittings are used as shown in Table 1. Table 1: Minimum fitting classes recommended for use with structured wall pipes Fittings according to: Pipe Stiffness ISO 9969 EN 1401-1 EN1852-1 EN12666 SN 2 SN 4 SN 8 SN 16 SN 2 SN 4 SN 8 SN 16 SDR 51 SDR 51 SDR 41 SDR 34 S 20 S 20 S 16 S 11.2 S 16 S 16 S 12.5 S 10 Where fittings of equal or higher stiffness than that of the pipe(s) are not available, fittings of lower stiffness may be used. In such cases guidance from the fittings manufacturer or supplier should be sought. Standard conditions of tender and sale apply. A copy of these conditions can be forwarded upon request 23 Weholite Jointing Socket Jointing (Elastomer Sealing Ring Joints) The integral socket joint can be delivered as sandtight or watertight (with rubber seal). The rubber seal conforms to international standards and is resistant to normal sewage waters. Seals resistant to oil contaminated water are available upon special request. Jointing must always be carried out in accordance with sound civil practice. However, in the absence of instructions the following is recommended: a. b. c. d. e. f. 24 Chamfer and deburr the spigot end when the sealing ring is in position in the socket. Use only sealing rings and lubricants supplied or approved by the manufacturer of the pipe or fitting. Ensure that cuts made on site are square. If necessary, set up a proper cutting zone. After cutting, chamfer or deburr the end to produce a finish equivalent to that of the pipe supplied by the manufacturer. Open profile closure needs to be repaired in pipes that will be air tested. Clean the pipe end, the socket and the sealing ring groove, removing any foreign matter, water, sand, dirt, etc. Make sure the sealing ring sits correctly in its location. Apply lubricant over the whole chamfered end, in the socket area or on the fixed sealing ring, as appropriate. Carefully align the spigot with the adjoining socket and push to the required insertion depth (depth of entry mark). If a lever is used on the pipe to push the joint, insert a block of wood between the lever and the end of the pipe to prevent damage to the pipe. Align the pipes vertically and horizontally Make sure that spigot end, socket and sealing ring are free from sand, moisture, dust, etc. Weholite Jointing 1. Install the rubber sealing ring in the groove. Make sure the tension in the rubber material is distributed evenly by applying force to the rubber ring. 2. Apply lubricant evenly onto the spigot end and the rubber sealing. Welded Joints Welded and fused joints should always be made by qualified personnel and in accordance with the manufacturer’s instruction and national standards. Extrusion welding is used for gravity applications where the joints must have full watertightness and tensile strength, as well as 100% resistance to root encrease. Welding will be undertaken by specially trained operators either from the inside or the outside of the pipe, or both. 3. Gently push the spigot onto the socket using adequate force until the stop mark (depth of entry mark) made on site is at the socket opening. Use a plate or plank to avoid damage to the spigot or socket. Large dimensions may be installed by using an excavator. Protect the socket opening with a sheet or plank. Check that the sealing ring stays in position. 25 Connection to Existing Pipes Weholite pipelines can be connected to existing pipelines or to structured wall pipelines of a different design in a way similar to a repair (see Repairs) by using an appropriate fitting. For saddle connections, follow the saddle manufacturer’s instructions. Connection to Rigid Structures • • • • • Pull the couplings over the joint so that they are centrally located over the joints. Check the line and level of the newly installed pipe. Tighten all bolt tensioners evenly so that all the slack is taken up before tightening fully to 20-25Nm. The embedment should then be replaced to give compaction values approximately equal to those immediately adjacent to the repair. Prior to completing the backfill of the pipe, the bolts must be retensioned. Ideally, LP couplings should be retensioned on the morning after the repair has been carried out. A structure may be a wall of a building, an inspection hole, other pipelines, fittings such as valves or the like. The connection of a Weholite pipe to a structure depends on the pipe size as well as on the structure at the connection point. Connections must be made in such a way that the joint is tight and that no damage is done to the pipe. If a Weholite pipe is connected to a structure that may settle differently than the pipe, a flexible connection beneath the pipe in the vicinity of the structure must be used, or a transition zone permitting pipe movement, or a strengthening construction. Special fittings for this purpose are available and must be fitted in accordance with the manufacturer’s instructions (short length double-socketed pipe). Repairs Slip couplers or purpose-designed fittings are available for effecting repairs. It is recommended that the following general points should all be adopted, where applicable: • • • • The full extent of the damaged or failed section must be identified and removed. The cut pipe ends should be square and prepared for push-fit jointing. LP repair couplings should be placed in position on the exposed pipeline ends. The replacement pipe length should then be laid on the suitably prepared bed and the LP couplings moved into their final positions. Ensure that the bedding does not interfere with the couplings and that the pipe ends are clean. Wall Passings / Repairs CONCRETE STRUCTURE DETAIL A DETAIL A CL OF PIPE 26 BOX SECTION OF WEHOLITE PIPE CUT OUT AS SHOWN Weholite Jointing Threaded Joints* 1. 2. 1 Align the pipes vertically and horizontally. Make sure that the threads are free from sand, moisture, dust, etc. Thread the male end into the female end. The pipes can be rotated using a lever or band-sling. If necessary, an excavator can be used to help rotate the pipes. To facilitate the rotation, the pipes can be laid on planks or roller supports. 3. 4. 5. The joint as such is sandtight. If watertightness is required, the joint can be extrusion welded from the inside (NS>800mm), from the outside, or both. The joint can also be waterproofed using an external shrink sleeve or rubber sleeve. 2 *Threaded joints subject to availability. 3 4 5 27 Weholite Jointing Rubber-sleeve Joints Rubber-sleeve (LP) couplings are designed for jointing pipes in stormwater and other types of non-pressure applications in the construction, repair and maintenance of pipelines. These include: • Non-watertight jointing • As a joint for plain-ended pipes • Repair of existing pipelines • As an adapter between pipes of different sizes or materials Step 7: Re-visit each nut to ensure the correct torque rating is achieved. Step 8: The correctly assembled coupling should sit neat and straight, centrally located over the 20mm gap between the two pipe ends. 1 5 2 6 3 7 4 8 Fitting Instructions Weholite LP Coupling Step 1: Pipe surface to be checked for damage. If the pipe end is in a suitable condition, it should be cleaned and marked with a line 150mm from the end. The pipe end must be liberally greased to assist the rubber sleeve to slide over the pipe end. Step 2: The entire rubber sleeve must be pushed onto one pipe end. The two pipe ends must be positioned with a setting gap of 20mm. The rubber sleeve must be slid back over the 20mm gap between the two pipe ends. The gasket must be located centrally between the marks made on each pipe end. Step 3: The first outer strap must be positioned and finger tightened in an outer groove of the rubber sleeve. Step 4: The second outer strap must be positioned and finger tightened in the other outer groove of the rubber sleeve. Step 5: The required size of socket (24mm) and the required torque rating (45Nm) is specified on the sticker by the fastening arrangement on the coupling. Step 6: Tighten the outer bolts to the recommended torque rating of 45Nm. Tighten the inner-sleeve bolts to the recommended torque rating of 45Nm. 28 Weholite Jointing GUIDELINE 2nd PIPE PLACED IN TRENCH, WITH CORRECT HORIZONTAL AND VERTICAL ALIGNMENT LP COUPLING FITTED TO PIPE BEFORE PLACING IN TRENCH. APPLY LUBRICANT IF REQUIRED 1 000 DETAIL 1 PIPE BEDDING REMOVED LOCALLY 25 25 SLIDE LP COUPLING ACROSS THE JOINT UNTIL IT IS EQUIDISTANT BETWEEN THE GUIDELINES Deviation from straightness It is normal practice in sewerage and drainage that pipes are installed in straight lines. However, as Weholite pipes are longitudinally flexible, it is possible to bend them if required during the installation. In such cases, minor misalignments of the pipeline can be accommodated in the pipe itself by bending. The minimum permissible bending radius for Weholite pipes under normal installation conditions = 50 * De (outside diameter). There may not be any bending at the socket. An acceptable bending radius can be maintained by lateral supports against the side of the trench. Special care should be taken when bending pipes at low temperatures, and the joint must be protected against any extra stress. The largest permitted angular deflection in the elastomer ring seal joint (the design angle) is PIPE BEDDING TO BE REPLACED AND TAMPED DETAIL 2 - LP COUPLING CORRECTLY POSITIONED 2° for de<315 mm 1.5° for 315≤de≤630 1° for de>630 Large angular deflections are permitted in the case of joints specifically designed to accommodate such deflections. The manufacturer of the coupling will specify the permitted angular deflection. DETAIL 3 - PLAN VIEW OF FINAL JOINT ALIGNMENT (LP COUPLING OMITTED FOR CLARITY) 29 Weholite Pipelaying Installation Types and Related Consolidation Deformation “Moderate” compaction, Cf=2.0 Design Graph An intensive study of the deflection history of pipes installed under different conditions is presented in the graph. The average deflections immediately after installation are represented by the lower boundary of each area, and the maximum values by the upper. 12 “None” compaction in clay, Cf=4.0 10 8 The embedment soil of a cohesive type is added without compaction. Installation of this type is NOT recommended. 6 NOT RECOMENDED 4 MODERATE 2 WELL 0 2 4 Cf = Consolidation factor. 8 16 Ring stiffness [kN/m 2 ] Pipe deflection after installation “Well” compaction, Cf=1.0 The embedment soil of a granular type is placed carefully in the haunching zone and compacted, followed by placing the soil in layers of 300mm maximum, after which each layer is compacted carefully. A layer of at least 150mm must cover the pipe. The trench is further filled with soil of any type and compacted. Typical values for the Proctor density are above 94%. 30 “None” compaction in granular soil, Cf=3.0 The embedment soil of a granular type is added without compaction. Installation of this type is NOT recommended. ( /d) inst -2 The embedment soil of a granular type is placed in layers of 500mm maximum, after which each layer is compacted carefully. A layer of at least 150mm must cover the pipe. The trench is further filled with soil of any type and compacted. Typical values for the Proctor density are in the range of 87-94%. Weholite Pipelaying Validity of the Design Graph The design graph is valid under the following conditions: • • • • • • • Depth between 0.8m and 6m, both included. Depth/diameter ratio at least above 2.0 Designers first need to establish permissible deflections, average and maximum (national requirements product standards, etc.). Pipes fulfil the requirements listed in the Weholite internal standard and international standards. Installation categories “well”, “moderate” and “none” reflect the workmanship on which the designer can rely. Sheet piles are removed before compaction. If the sheet piles are removed after compaction, the “well” or “moderate” compaction level will be reduced to the “none” compaction level. For the deflection mentioned in the graph, the strain will be far below the design limit and need not be considered in the design. Trench Work Bedding On the bottom of the trench, on top of an exchange material or on top of a grating, a 150mm-300mm thick bedding layer is prepared and well compacted (>95% Proctor). The bedding may consist of sand, gravel or crushed pebbles, free from stones within the width of the pipe trench. The bedding needs to be at least 200mm wider than the pipe outside diameter to enable proper compaction work. For installations in wet or soft soil, a geotextile must be placed under the bedding in order to prevent the bedding from being washed away. The largest permissible particle size dmax for natural stone materials to be used is determined on the outside diameter of the pipe to be installed. For DN<600, dmax = 0,1 • DN. For DN>600, dmax is always 60mm. Crushed pebble material must not be larger than 32mm and/or in accordance with national standards. If a pipeline is founded directly onto levelled native soil, the trenching work must be done carefully, avoiding unnecessary over-excavation, in order to keep the trench bottom sufficiently level. The whole bedding layer depth must be stone free. The size and shape of the trench are planned on the basis of the size of the pipe or pipes to be laid as well as the soil data gained from soil investigations. The trench is generally made as narrow as possible, taking into account the width needed for possible supporting structures, working space and space needed for proper placement of the backfill soil. The minimum width of the bottom of an open trench is 0.7m and that of a supported trench 1.0m. Making a trench unnecessarily wide should be avoided, as the effect of the side support might be weakened. When determining the trench depth, sufficient space for a bedding layer of at least 150mm must be taken into account, should the native soil be suitable as bedding. The final excavation is made carefully, so that the bottom of the trench is kept as undisturbed as possible. Moving about on a soft or easily disturbed trench bottom must be kept to a minimum. The slope of a trench wall and the need for support are determined on the basis of appropriate needs and general workplace safety aspects. The slope inclination and need for support are specified in the national standard specification for civil engineering construction. Laying Before starting to lay the pipe, check that the pipes and materials to be used are free from defects. Clean them carefully after transportation and any machining done before installation. The pipes are laid on the levelled trench bottom or bedding so that the pipe is supported evenly over its full length. Excavations are made in the trench bottom or bedding for the sockets, so that the weight of the pipes do not rest on the sockets. Do not lay pipes on top of wooden planks or similar. 31 Weholite Pipelaying During laying, the water level in the trench must be kept sufficiently low to prevent flotation or water from damaging the laid pipe. When laying work is interrupted, the ends of the pipes must be sealed to prevent ingress of dirt or water. The final layer of the primary backfill must extend 300mm above the crown of the pipe; to avoid ovalisation of the pipe, the soil layer on top of the pipe can only be mechanically compacted when it is at least 300mm thick. When laying pipes in road and railway areas, instructions from the relevant authorities must be observed. The degree of compaction must be at least 90-95% Proctor, if not otherwise stated in the contractor’s plan. When removing supporting structures (such as sheet piles or trench boxes), take care not to endanger work safety or trench wall stability, loosen the compacted backfill or move the pipe out of position. Backfilling The term “primary” refers to the material to be used around the pipe above the native soil trench bottom or the bedding. Primary backfill extends to at least 300mm above the pipe crown and/or as specified by local standards. The primary backfill material must meet the same requirements as the bedding materials. Backfilling should extend over the entire trench width. The primary backfill material may not be dropped on top of the pipe in such a way that the pipe is moved or damaged; it must be placed as evenly as possible on both sides of the pipe and packed under the pipe haunches and on the sides. The final backfill material may be compactable as-dug material, but must in any case be free from stones larger than 300mm. Where necessary, and especially in traffic areas, compaction is carried out in several 300mm layers to compaction levels corresponding to those of the primary backfill. On the surface, use backfill material that matches the surrounding surface. Structural Design In general, structural design of a pipeline by analytical or numerical methods is not needed. Any calculated prediction of the pipe behaviour depends greatly on the degree of correspondence between the calculation assumptions and the actual installation; it is therefore important to base the former on reliable input values obtained from extensive soil surveys and monitoring of the installation. However, when structural design is required, e.g. in cases where no other information exists, a method as defined in EN 1295-1 should be used. As far as input values for the pipes are required, the following values are recommended: In the first stage, the material is spread in the trench with a spade or by other means and compacted so that the pipe is not moved or damaged. If necessary, the pipe may be pressed down or anchored or filled with water to prevent it from lifting during compaction. The backfill material is compacted in layers of 150-300mm. 32 Material PE Remarks E-modulus (Mpa) 1000 Modulus of elasticity (-) 0.4 Poisson’s ratio -5 (mm/mm.K) 13 x 10 Lin. expansion coefficient Pressure Testing Pressure Testing on Non-Pressure Pipes on Site Method a. b. Testing In the acceptance inspection, if required, compliance of the installation work with the planning documents is verified. As part of the final inspection, tightness can be tested. Tightness testing of Weholite pipes is performed with reference to national requirements, but normally according to the following alternative methods: SABS 1200 LD 1982 Standard specification for civil engineering construction; LD sewers SFS 3113. Leak testing on pipelines is conducted either with air or water. ℓ = litre of added water m = length of piping in metres h = hour The value thus obtained and the inside diameter of the pipe are inserted in the diagram below. All readings below the line are acceptable. For further information, see Standard SFS 3113. Principle (Summary of the Finnish standards SFS 3113) A delimited section of pipe is filled with water and subjected to a certain overpressure. The tightness is determined in the final stage of the test by determining the quantity of additional water needed to maintain the pressure. The necessary overpressure in the pipe depends on the level of the ground water in relation to the level of the piping to be tested. The difference between these two levels is marked with “a”. The overpressure is derived from the following graph: l/m h 2,6 2,4 Difference between the subsoil water and the pipe (m) a<0 0<a<5 0.5<a<1.0 1.0<a<1.5 1.5<a<2.0 2.0<a<2.5 2.5<a<3.0 3.0<a<3.5 3.5<a<4.0 4.5<a<5.0 Test overpressure Pe1 kPa Bar 10.0 15.5 21.0 26.5 32.0 37.5 48.5 54.0 59.5 65.5 0.1 0.155 0.21 0.265 0.32 0.375 0.485 0.540 0.60 0.65 2,2 2,0 1,8 1,6 1,4 1,2 1,0 duration of the test Volume of the added water per length unit and the c. Fill a pipe section with water to overpressure P. Check that all seals are watertight and hold the pressure for 10 minutes. The overpressure is maintained at the level P during half an hour by adding water when necessary. Measure the volume of water added during three 6-minute intervals. When the test is completed, the average volume of the added water is calculated. This volume is converted into functions of pipe length and time (ℓ/mh),: 0,8 0,6 0,4 0,2 0 200 400 600 800 1 000 1 200 1 400 1 600 Inside diameter mm 33 Testing SABS 1200 LD Sewer 1982 General All acceptance tests shall be carried out in the presence of the engineer and at such times and in such manner as the engineer may direct. Subject to the provision of 7.1.5, no pipe joint or fitting shall be covered until the applicable tests given in 7.2 have been completed and the engineer has: a. b. given his written acknowledgement that the sewer or the specified section of it has passed the said test, and authorised such covering. The sewer or any section of it shall be inspected by the contractor who, if he deems it ready to be tested, shall advise the engineer of his intention to subject the sewer or said section of it to the appropriate tests. The sewer shall be tested in sections between manholes or chambers, as applicable, the section being tested must be isolated from other sections by means of suitable plugs or stoppers that have been braced adequately. Notwithstanding any acknowledgement by the engineer in terms of 7.1.2, after backfilling and compaction have been completed, the engineer may order that the sewer be retested to check that it has not been disturbed or damaged during backfilling. The engineer may order one of the following to be carried out on the sewer or any section of it: a. b. c. 1. an air test on pipes (other than concrete pipes) of all sizes; or 2. in the case of pipes (other than concrete) of diameter up to 600mm, an air test followed by a water test; a water test in the case of pipes of diameter up to 750mm; a visual internal inspection in the case of pipes of diameter greater than 750mm. The contractor shall provide all labour and apparatus (including expansive plugs and flexible bag stoppers) that may be required for carrying out the tests. All test results shall be recorded in the manner directed, whether or not the pipeline or section of pipeline has passed the test. 34 Tests and Acceptance/Rejection Criteria Air Test Pipelines above the water table: An approved air testing machine shall be used to raise the gauge pressure in the section of the pipeline under test first to 3.75 kPa. After a 2 min stabilisation period, the pressure shall be reduced to 2.5 kPa. The machine shall then be switched off and the time taken for the pressure to drop from 2,5 kPa to 1.25 kPa shall be determined. The time taken shall be at least the applicable of the following values: Nominal diameter of pipe (mm) Minimum time (min) taken for pressure to drop from 2.5 kPa to 1.25 kPa 100 150 200 225 250 300 375 450 600 750 2.0 3.0 4.0 4.2 4.5 6.0 7.5 9.0 12.0 15.0 Pipelines below the water table: An approved air testing machine shall be used to raise the gauge pressure in the section of the pipeline under test to 2.5 kPa above the static water pressure. After this pressure has been attained and the machine stopped, any change in pressure shall be noted. There shall be no discernible loss for a period of at least 5 min. Water Test The section of the pipeline under test and, unless otherwise specified, the manhole chamber at the upper end of the said section shall be filled with water to such a depth that every portion of the pipeline is subjected to a pressure of not less than 12 kPa and not more than 60 kPa. During the test, there shall be no discernible leakage of water. An appropriate period, which shall be at least 10 min, shall be allowed for initial absorption, and the loss of water over the next 30 min shall be noted. The amount lost shall not exceed the applicable of the following rates per 100m of pipeline per hour: Nominal diameter of pipe (mm) 100 150 200 225 250 300 375 450 600 750 Minimum time (min) taken for pressure to drop from 2.5 kPa to 1.25 kPa 6.0 9.0 12.0 13.5 15.0 18.0 22.5 27.0 36.0 45.0 Should any section of the pipeline fail to pass the water test, a retest will be permitted and, in such case, acceptance or rejection of the section shall be determined on the result of the retest. Rejection In the case of AC, vitrified clay and pitch-impregnated fibre pipes, failure under the air test will be deemed to be cause for rejection. After such rejection, the contractor may apply a water test to locate the source of failure, rectify the pipeline, and re-apply the air test. In the case of reinforced concrete, failure under the water test will be deemed to be cause for rejection. Test of Connecting Sewers Each connecting sewer shall be tested between its upper end and the junction at the main sewer. The upper end of the connection shall be kept securely closed with expanding plugs during the test. Where practicable, the contractor may test the main and connections simultaneously if he so wishes. On completion of the test, the upper end of the connection shall be permanently sealed as directed by means of a plug stopper suitable for the type of pipe. Test of Rising Mains After a rising main has been laid and the joints completed, the main shall be slowly charged with water, so that all air is expelled, and then tested in accordance with Subclause 7.3 of SABS 1200 L. Watertightness of Manholes Where so required in terms of the project specification, manholes shall be tested for watertightness separately from the pipeline. 35 Support Spacing and Buoyancy Support Spacing With installations above ground, the maximum support spacing can be determined according to the figure on the left hand side. Support spacing - sag 10mm/10 years - liquid density 1000kg/m3 5 + 20 °C 4 + 40 °C 3 + 60 °C 2 1400 1200 1000 800 600 400 200 1 0 Support spacing, m 6 Pipe ID, mm Buoyancy When installing pipes under the ground water level, the buoyancy of the pipe must be taken into consideration. Where necessary, the natural uplift of the pipe should be counteracted. This can be designed case by case. Please do not hesitate to contact your nearest Marley branch for technical information. 36 DN/ID mm dn mm Pipe Empty Profile Empty kN/m Pipe Full Profile Empty kN/m Pipe Full Profile Full N/m 360 400 500 600 700 800 1000 1200 1400 1500 1600 1800 2000 2200 400 450 560 675 790 900 1125 1350 1575 1680 1792 2016 2240 2464 1.23 1.52 2.38 3.43 4.66 6.09 8.97 13.70 18.65 21.41 24.36 30.83 38.06 46.04 0.24 0.29 0.45 0.65 0.89 1.16 1.27 2.61 3.55 4.08 4.64 5.87 7.25 8.78 10 10 10 10 20 20 30 40 50 60 70 90 110 130 General Notes and Limitations General Notes This Structured Wall Pipe (Weholite) Manual has been produced as a guide for engineers, purchasing officers and contractors to cover the application and use of Weholite pipes and fittings. This document will be reviewed from time to time in order to keep it fully relevant to modern water and wastewater industry practice. Any comments and suggestions regarding its content will be appreciated. The information contained herein is intended as a guide, and its accuracy and applicability is not guaranteed. Marley Pipe Systems assumes no obligation or liability in respect of this information. All tables and statements may be considered as recommendations, but do not constitute a warranty. Users of our products should carry out their own tests to determine the suitability of each product for their particular purposes. Marley’s liability for defective products is limited to the replacement, without charge, of any product found to be defective in line with their standard condition of tender and sale. In no circumstances shall it be responsible for any damages beyond the price of the products, and in no event shall it be liable for consequential damages. Limitation of Liability Whilst the information, opinions, advice and recommendations contained in this publication have been prepared with proper care, they are offered only in order to provide useful information to those interested in technical matters associated with pipeline design, selection and installation. The information contained herein is not intended to be an exhaustive statement of all relevant data, as the successful installation in each case may depend on numerous factors beyond our control. Marley Pipe Systems accepts no responsibility for or in connection with the quality or standard of any pipeline or installation or its suitability for any purpose when installed. All conditions, warranties, obligations and liabilities of any kind which are or may be implied or imposed to the contrary by any statute, rule or regulation or under common law and whether arising from the negligence of the Company, its servants or otherwise, are hereby excluded except to the extent that the Company may be prevented by any statute, rule or regulation from doing so. 37 Conversion Factors Numerical values of SR corresponding to some standard classification series. SR (kN/m2 = kPa) SR (MN/m2 = MPa) SR ((psi) acc. ASTM 28) Stiffness (kPa) SANS 1601 PVC (D/s = SDR) PVC (ISO S-series) PVC (s/Dm%) PVC (PN bar) HDPE 63 (PN bar = s/Dm%) HDPE100 SDR 2 0.002 16 100 51 25 2 4 3.2 33 4 0.004 32 200 41 20 2.5 5 4 26 8 0.008 64 400 33 16 3 6 5 21 16 0.016 128 800 26 12.5 4 8 6.3 17 32 0.032 256 1600 21 10 5 10 8 13.6 For GRP pipes, SR is also used for pipe classification but the unit is commonly N/m2 (Pa) according to ISO, e.g. 1000 times larger than the standard values for thermoplastics. A common series is 2500, 5000, 10000 and 20000 N/m2. In the USA, the ring stiffness concept is also used, but is then defined according to ASTM and expressed in psi. The numerical values in psi in the above table are 8 times larger than those given above in kN/m2, e.g. 16, 32, 64, etc. A common pipe stiffness series used in the USA for GRP is 18, 36 and 72 psi. Volume (litres, cubic feet, gallons) Gallons (US) Gallons (lmp) Volume (m , cubic yards, gallons) 3 Litre (dm3) Cubic Feet 1 0.0353147 0.264171 28.3168 1 7.480456 6.2288 3.78542 0.133682 1 0.83268 4.54609 0.160544 1.20094 1 0.00454609 0.219969 Volume (m , acre feet, morgen feet, gallons) 3 1 1.30795 264.171 219.969 0.76455 1 201,974 6.2288168.178 0.003785 0.00495115 1 0.83268 0.0059461 1.20094 1 ft3/second Gal (lmp/min) Flow m3 (kilolitre) Acre Feet 1 0.00081071 0.000383038 219.969 1 0.001 0.0353147 13.19814 1233.48 1 0.47247 271328 1000 1 35.3147 13198.14 2.11654 1 574275 28.3168 0.0283168 1 373.73 1 0.0757682 75.7682 x 106 0.002676 1 2610.71 0.00454609 38 Morgen Feet Gallons (lmp) Cubic Metres Cubic Yards Gallons (US) Gallons (lmp) 0.000003686 0.0000017413 Litre/second m3 /second Conversion Factors Force Newton Kilogram Force Metric Ton - Force Pound - Force Ton (2000lb Force) Ton (2240 lb) Force 1 9.80665 9806.65 4.44822 8896.44 9964.02 0.101972 1 1000 0.453592 907.184 1016.05 0.101972 x 103 103 1 0.453592 x 103 0.907184 1.01605 0.274809 2.20462 2204.62 1 2000 2240 0.112405 x 105 1.10231 x 103 1.10231 x 103 0.0005 1 1.120 0.10036 x 103 0.984206 x 103 0.984296 0.446429 x 103 0.892858 1 Pressure Pascal (Newton/m2) Bar 1 10-5 105 98.0665 x 10 3 6894.76 Kilogram Pound Force Metre head per inch2 of water Force/cm2 Foot head Ton (2000lb) Ton (2240lb) of water force/in2 force/in2 0.101972 x 10-4 0.145038 x 10-3 0.101972 x 10-3 0.33455 x 10-5 0.072519 x 10-6 0.064749 x 10-6 1 1.01972 14.5038 10.1972 33.455 0.0072519 0.006479 0.980665 1 14.2233 10 32.8084 7.11167 x 10 0.0005 -3 6.34971 x 10-3 0.446429 x 10-3 0.0689476 0.070307 1 0.70307 2.306727 3 0.0980665 0.1 1.42233 1 3.28084 0.711167 x 10 0.634971 x 10-3 2.98898 x 103 0.0298898 0.03048 0.433515 0.3048 1 0.21676 x 10-3 0.193533 x 10-3 13.7895 x 106 137.895 140.614 2000 1.40614 x 103 4.61332 x 103 1 0.892858 15.4443 x 106 154.433 157.488 2240 1.57488 x 103 5.16692 x 103 1.120 1 9.80665 x 10 -3 39 Notes: 40 CONTACT US! Y o u r V a l u e P a r t n e r Gauteng East Gauteng North 1 Bickley Road, Pretoriusstad, Nigel Tel: +27 11 739-8600 | Fax: +27 11 739-8680 1 Piet Pretorius Street, Rosslyn, Pretoria Tel: 0861 MARLEY (627539) For additional information on the latest product offerings from Marley Pipe Systems visit www.marleypipesystems.co.za For more information on Marley Pipe Systems’ range of plastic pipes and fittings or for any technical advice and to locate your nearest Marley stockist, contact one of our branch offices below. 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