Warren Controls PICV Series - Manual (Page 28)

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2600 Emrick Blvd • Bethlehem, PA 18020 • USA • 800-922-0085 • www.warrencontrols.com
PICV SET DIFFERENTIAL PRESSURE
ADJUSTMENT
1. Remove line pressure and isolate PICV valve in piping.
2. Remove upstream port and downstream port pressure sensing
lines from connections on diaphragm actuator (See drawing
C3121902).
3. Connect flexible temporary air connection to upstream port
pressure sensing connection on diaphragm actuator (See
drawing C3121902 for location of upstream port pressure
sensing connection).
4. Use marking pen to place mark on valve stem just above where
it enters the valve.
WARNING:
In Steps 5 thru 10, do not
turn the adjusting screw so it extends more
than 3-3/4 inches (9.53 cm) above the top of
the actuator (more than 26 threads are visible
on the adjusting screw). Doing so may cause the
adjusting screw to separate from the actuator
resulting in damage and personal injury from
the uncontrolled release of pressure inside the
actuator. Be careful not to damage the seal in
the seal washer on the adjusting screw. The
seal may be damaged by excessive turning of
the adjusting screw or by pushing it over the
screw’s threads. If the seal in the seal washer
is damaged the actuator will leak when line
pressure is returned to the valve.
5. Loosen locknut on adjusting screw on top of actuator and
separate from seal washer. Thread locknut only to top of
adjusting screw.
6. Apply air pressure to upstream port pressure sensing connection
equal to desired set differential pressure plus ½ psig (0.034 BAR).
Example: For set differential pressure of 5 psig (0.345 BARG),
apply 5-½ psig (0.379 BARG) to upstream port pressure sensing
connection. If mark made on valve stem in Step 9 moves away
from valve, turn adjusting screw clockwise, looking down on
actuator, until mark returns to its closest point to the valve.
7. Turn adjusting screw slowly counter-clockwise, looking down on
actuator, a ½ turn at a time until mark made on valve stem in
Step 9 just begins to move away from the valve.
8. Reduce air pressure to upstream port pressure sensing
connection to 0 psig (0 BARG) and allow all air to bleed from
actuator.
9. Slowly increase air pressure to upstream port pressure sensing
connection until equal to desired set differential pressure. Mark
made on valve stem should just begin to move away from the
valve when pressure reaches desired set differential pressure.
If mark moves too soon, turn adjusting screw clockwise an
additional ½ turn then repeat Steps 13 and 14. If mark does not
move, turn adjusting screw counter-clockwise an additional ½
turn then repeat Steps 13 and 14. Satisfactory adjustment should
be made within 2 additional full turns of the adjusting screw.
10. Thread locknut on adjusting screw down to top of actuator
and tighten securely against seal washer to create seal against
actuator. If the locknut is not tightened securely the actuator
will leak when line pressure is returned to the valve.
11. Install upstream port and downstream port pressure sensing
lines (See drawing D3121311 (Sizes 2-1/2 thru 4 inch, P2 thru P4)
or C3121900 (Sizes 5 thru 10 inch, P5 thru P1) for orientation of
upstream port and downstream port pressure sensing lines).
12. Return line pressure to valve.
DPRV
ACTUATOR
INSTRUCTIONS
C3121902