User Manual
User Manual
Page 5 April 2014
INSTALLATION INSTRUCTIONS, SINGLE SUPPORT
1. Choose the proper location to install the AHL-GD Dierential 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 Dierential 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
OTE:N 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withdrawn, close the ball valve and dismantle the drilling machine.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 ow. See Figure 4 and Figure 5.
8. Install the instrument valves (optional) at the pressure connections located on the AHL-GD Dierential Pressure Flow Meter
sensor head. Ensure that the valves are fully closed before proceeding.
H L
SCH/WALL
MOD/β
DIA/ID
CAP
DP
TAG
FLOW METERS
W/O
SCH/WALL
FLOW METERS
W/O
H L
FLOW
FLOW
Field Weld
Figure 4: Flow indication arrow
9. Open the isolating ball valve. Insert the AHL-GD Dierential 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.