Install Instructions

BYPASS LINE
GATE VALVE
MAIN VALVE
1/4
"
FEEDBACK CONTROL LINE - PITCH AWAY
FROM PILOT, AVOID WATER POCKETS
GATE VALVE
4 PIPE DIAMS.
D MINIMUM
SPRING PILOT
D
3
Figure 2
9. Install a downstream feedback control line to sense pressure at the point of desired pressure
control using 1/4 black steel pipe. Install a 1/4 NPT shut-off valve in this line. The feedback
control line should connect to the top or side of the main valve outlet line at least 10 pipe diameters
downstream of any valves or elbows, at a point of minimum turbulence (See Figure 2).
Note: Avoid sensing the downstream pressure immediately at the main valve outlet or after a turn.
When the delivery pipe expands in size, select a spot at least 4 pipe diameters beyond the point of
enlargement (See Figure 2).
10.The feedback control line should pitch down from the pilot to avoid erratic operation and excessive
fouling. Eliminate water pockets.
11.Install a pressure gauge in the feedback control line to show the pressure actually reaching the
pilot diaphragm.
2. Make sure the bleed orifice is installed in the 1/8 NPT tapping on the outlet end of the main valve on
the opposite side from the U-tubing. Remove the 1/8 NPT pipe plug from the bleed orifice and
replace it with a 1/8 NPT x 1/4” (6mm) O.D. tubing, straight compression fitting.
3. Install the 1/4 NPT x 1-1/2” (38mm) nipple and half the union connection on the inlet end of the
main valve.
4. Use the 1/4 NPT x 4” (101mm) nipple and the remaining half of the union connection to mount
the pilot.
5. Install the T-fitting on the 1/8 NPT tapping on the side of the pilot with the T pointing down.
6. Install the L-fitting in the tapping at the center of the main valve diaphragm cover.
7. Install the S-tubing from the side of the T-fitting to the bleed orifice on the main valve.
8. Install the L-tubing from the bottom of the T-fitting to the L-fitting in the main valve
diaphragm cover.