Ellipse® Pitot Tube Meter
AHL-GD Differential Pressure Flow Meter
ERS
MET
FLOW
W/O
L
WAL
/β
MOD
ID
DIA/
CAP
SCH/
DP
TAG
PTT-UM-00327-EN-02 (April 2014)
User Manual
Ellipse® Pitot Tube Meter, AHL-GD Differential Pressure Flow Meter
CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pipe Orientation and Sensor Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Installation Instructions, Single Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Installation Instructions, Double Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Location Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Flow Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Page ii
April 2014
User Manual
INTRODUCTION
The Preso patented elliptical design outperforms and provides greater
accuracy than traditional differential pressure flow measurement devices. This
differential pressure flow meter is designed with a series of ports facing the
upstream velocity pressures, as well as flow sensing ports strategically located
ahead of the trailing edge flow separation.
The multi-ported, self-averaging flow element consists of an elliptical shape
with two independent flow sensing chambers. The impact velocity sensing
holes (high pressure) are located along the leading edge and the true static
sensing holes (low pressure) are on the exterior probe side. Model AHL-GD
comes with instrument shutoff valves with provisions to accept a transmitter
or direct indicating meter.
True Static
Sensing Holes
Impact Velocity
Sensing Holes
Figure 1: AHL-GD Ellipse pressure sensing holes
SPECIFICATIONS
Applications
Air, liquids and gases
Pipe Sizes
2…72 in. (50…1829 mm)
Pressure
800 psi (5515 kPa) maximum
Temperature
800° F (426° C) maximum
Accuracy
±0.75% of reading
Turndown Ratio
17:1 with no vacuum effect
Standard Components
T-type head, 316 SS 1/4 in. or 1/2 in. FNPT connection
CS 3000 lb. thread fitting, ASTM A105
316/316L SS Ellipse sensor
Instrument valves (2 per sensor), 1/4 in. or 1/2 in., CS
316 SS ID tag with wire
150 lb. 316/316L SS sensor flange
CS packing chamber with molythane or graphite packing gland
CS packing chamber flange, 150 lb. with SS cap
316 SS isolation ball valve, NPT threaded
CS threaded nuts and bolts
CS nipples, schedule 40
Reynolds Number
Greater than 75,000 maintains most accurate flow measurements
Less than 75,000 consult factory for estimated results
Resonance
Less than 0.8 but greater than 1.2. If greater than 0.8, use double support. System shutdown
is required when the double support option is used. Select larger diameter ellipse to avoid
double support.
Table 1: AHL-GD specifications
April 2014
Page 3
Ellipse® Pitot Tube Meter, AHL-GD Differential Pressure Flow Meter
PIPE ORIENTATION AND SENSOR MOUNTING
H
FLOW
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
SCH/WALL
10°
10°
Field Weld
Lock Nuts
Field Weld
10°
10°
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
H
FLOW
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
Air, Gas, or Liquid
with Proper Bleeding
SCH/WALL
L
Liquid
Figure 2: Horizontal pipe installation
FLOW
FLOW
or
5° Max.
5° Max.
Field
Weld
MOD/β
DIA/ID
CAP
DP
TAG
FLOW METERS
W/O
Liquid, Air and Gas
Note:
SCH/WALL
W
F
L
O
Illustration represents installation for downward flow.
Sensor Alignment
Note:
Probe alignment applies to all
horizontaland vertical installations.
Figure 3: Vertical pipe installation and sensor alignment
Page 4
April 2014
User Manual
INSTALLATION INSTRUCTIONS, SINGLE SUPPORT
1. Choose the proper location to install the AHL-GD Differential Pressure Flow Meter using AGA/ASME standards (or
equivalent). Refer to the location diagrams Figure 2, Figure 5 and Figure 6.
2. Grind the surface of the pipe where the AHL-GD Differential Pressure Flow Meter is to be inserted to provide a clean area
for welding.
3. Weld the supplied thread-o-let to the pipe using standard codes for your application (1/16 in. weld gap recommended).
Take care to protect the threads during the welding process.
4. Install the close nipple by threading it into the weld connector. Next, install the supplied 3-piece isolating ball valve.
5. Mount the high pressure drilling machine onto the ball valve. Open the ball valve. Drill a hole through the pipe wall
according to Table 2.
Model/Sensor
Weld Connector
Drill Bit
AHL-GD (7⁄8 in.)
1-1/4 in.
1-1�8 in.
AHL-GD (1-1/4 in.)
1-1/2 in.
1-3�8 in.
Table 2: Single support drill bit size
NNOTE: There is no need for a drilling machine if it is not a hot tap installation or if the system is not pressurized.
6. Having drilled through the pipe, withdraw the drill bit through the isolating ball valve. Once the drill bit has been
withdrawn, close the ball valve and dismantle the drilling machine. Ensure that there is no leakage at the valve and close
nipple connections. The ball valve is to remain completely closed until step 9.
7. Install the cage nipple assembly and packing gland with the threaded rods assembly by threading it into the isolating ball
valve. Align the arrow on the sensor head with the direction of flow. See Figure 4 and Figure 5.
8. Install the instrument valves (optional) at the pressure connections located on the AHL-GD Differential Pressure Flow Meter
sensor head. Ensure that the valves are fully closed before proceeding.
H
FLOW
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
L
H
FLOW
L
FLOW METERS
W/O
SCH/WALL
Field Weld
Figure 4: Flow indication arrow
9. Open the isolating ball valve. Insert the AHL-GD Differential Pressure Flow Meter sensor into the pipe until it reaches the
opposite pipe wall. This should be done by turning the threaded insertion rods clockwise using a wrench.
10.Connect the instrument lines to the sensor head valves. In turn, connect these lines to a gage or transmitter.
April 2014
Page 5
Ellipse® Pitot Tube Meter, AHL-GD Differential Pressure Flow Meter
INSTALLATION INSTRUCTIONS, DOUBLE SUPPORT
1. Follow steps 1 through 6 in the single support section. At 180° from and on the same plane as the previously drilled hole,
grind the surface of the pipe to provide a clean area for welding. Drill a hole and de-burr, especially on the inside of the
pipe. The hole used for the double support should be sized according to Table 3.
Model/Sensor
Weld Connector
Drill Bit
AHL-GD (7⁄8 in.)
1/8 in.
3/8 in.
AHL-GD(1-1/4 in.)
1 in.
7⁄8 in.
Table 3: Double support drill bit size
2. Weld the double support thread-o-let making sure that it is centered with the drilled hole (1/16 in. weld
gap recommended).
3. Install the AHL-GD Differential Pressure Flow Meter sensor through the two holes. Make sure that the double support pin
passes through the guide ring. See Figure 5.
Ellipse Sensor
Double Support Pin
Guide Ring
Figure 5: Double support installation
4. Align the arrow located on the sensor head in the direction of flow as shown in Figure 4.
5. Ensure that the AHL-GD Differential Pressure Flow Meter is in the correct orientation and spans the inside of the pipe.
Tighten the threaded insertion rods until the sensor reaches the other end of the pipe.
6. Install the plug into the end of the double support thread-o-let. Tighten the plug to prevent leakage.
Page 6
April 2014
User Manual
LOCATION INSTRUCTIONS
Accuracy is affected by the piping configurations due to the disturbances of the flow profile. A fully developed symmetrical
flow profile is achieved with the minimum upstream and downstream recommended lengths.
DISTANCES ARE EXPRESSED IN
NUMBER OF NOMINAL PIPE DIAMETERS
THROTTLED VALVE OR REGULATOR
27
4
H
TWO ELBOWS IN DIFFERENT PLANES
24
4
L
H
Preso
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
FLOW
11
4
5
H
10
5
FLOW
9
MOD/β
DIA/ID
CAP
DP
TAG
Preso
FLOW
H
L
Preso
FLOW METERS
W/O
L
FLOW METERS
W/O
SCH/WALL
Preso
TWO ELBOWS IN THE SAME PLANE
11
3
4
H
H
SCH/WALL
Straightening Vane
CHANGE IN PIPE SIZE
MOD/β
DIA/ID
CAP
DP
TAG
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
2
4
4
5
Preso
SCH/WALL
Straightening Vane
9
Preso
H
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
2
SCH/WALL
FLOW
Regulator or Partially
Closed Valve
6
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
Preso
FLOW
FLOW
4
10
FLOW
4
6
4
L
FLOW METERS
W/O
SCH/WALL
H
FLOW
Straightening Vane
L
FLOW METERS
W/O
L
Preso
SCH/WALL
2
2
2
3
5
MOD/β
DIA/ID
CAP
DP
TAG
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
Preso
9
4
4
6
H
H
MOD/β
DIA/ID
CAP
DP
TAG
10
SCH/WALL
Preso
FLOW
Straightening Vane
FLOW
Straightening Vane
A SINGLE ELBOW
7
3
H
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
Preso
FLOW
5
3
3
2
H
L
FLOW METERS
W/O
MOD/β
DIA/ID
CAP
DP
TAG
SCH/WALL
Preso
2
FLOW
Straightening Vane
Figure 6: Location instructions
April 2014
Page 7
FLOW CURVE
4
3
2
12" 16" 20"
14" 18"
24"
30"
WATER 60 °F
5 6 789
100000
5"
6"
2
3
8"
4
10"
5 6 789
10000
USGPM
2"
2
2.5"
3
4
3" 3.5" 4"
5 6 789
1000
5 6 789
1
.2
.3
.4
2
1
.9
.8
.7
.6
.5
3
2
4
3
4
5
6
10
9
8
7
NOTE:
2…10 in. CURVES ARE FOR SCHEDULE 40 PIPE
12 in. AND ABOVE ARE FOR SCHEDULE STANDARD PIPE
2
20
–
ES
O
40
30
∆P
INC
H
2
ANNULAR ELLIPSE ®
10
OF
H
100
90
80
70
60
50
3
4
5 6 789
100
Figure 7: Pressure drops
Control. Manage. Optimize.
PRESO is a registered trademark of Badger Meter, Inc. Other trademarks appearing in this document are the property of their respective entities. Due to continuous research,
product improvements and enhancements, Badger Meter reserves the right to change product or system specifications without notice, except to the extent an outstanding
contractual obligation exists. © 2014 Badger Meter, Inc. All rights reserved.
www.badgermeter.com
The Americas | Badger Meter | 4545 West Brown Deer Rd | PO Box 245036 | Milwaukee, WI 53224-9536 | 800-876-3837 | 414-355-0400
México | Badger Meter de las Americas, S.A. de C.V. | Pedro Luis Ogazón N°32 | Esq. Angelina N°24 | Colonia Guadalupe Inn | CP 01050 | México, DF | México | +52-55-5662-0882
Europe, Middle East and Africa | Badger Meter Europa GmbH | Nurtinger Str 76 | 72639 Neuffen | Germany | +49-7025-9208-0
Europe, Middle East Branch Office | Badger Meter Europe | PO Box 341442 | Dubai Silicon Oasis, Head Quarter Building, Wing C, Office #C209 | Dubai / UAE | +971-4-371 2503
Czech Republic | Badger Meter Czech Republic s.r.o. | Maříkova 2082/26 | 621 00 Brno, Czech Republic | +420-5-41420411
Slovakia | Badger Meter Slovakia s.r.o. | Racianska 109/B | 831 02 Bratislava, Slovakia | +421-2-44 63 83 01
Asia Pacific | Badger Meter | 80 Marine Parade Rd | 21-04 Parkway Parade | Singapore 449269 | +65-63464836
China | Badger Meter | 7-1202 | 99 Hangzhong Road | Minhang District | Shanghai | China 201101 | +86-21-5763 5412
Legacy Document Number: 10-PTT-UM-00301