Cashco SA1 - Manual (Page 2)

IOM-CA1/SA1 2
IV. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register
on the diaphragm. The registering pressure is the
outlet, P2, or downstream pressure. The range
spring op pos es di a phragm movement. As outlet
pressure drops, the range spring pushes the di a-
phragm down, opening the port; as outlet pres sure
V. STARTUP
1 Start with the block valves closed.
2. Relax the range spring by turning the ad just ing
screw (1) CCW (viewed from above) a minimum
of three (3) full rev o lu tions. This reduces the outlet
(down stream) pres sure set point.
3. If it is a “hot” piping system, and equipped with
a bypass valve, slowly open the bypass valve
to preheat the system piping and to allow slow
ex pan sion of the piping. Closely monitor outlet
(down stream) pressure via gauge to ensure not
over-pressurizing. NOTE: If no bypass valve is
in stalled, extra caution should be used in start ing
up a cold system; i.e. do everything slowly.
SECTION VI
6. Continue to slowly open the inlet (upstream) block
valve until fully open.
7. Continue to slowly open the outlet (downstream)
block valve, especially when the downstream pip-
ing system isn’t pressurized. If the outlet (down-
stream) pressure exceeds the desired pres sure,
close the inlet block valve and go to Step 2. Close
bypass valve approximately 25%, and re peat pro-
ce dure.
8. When fl ow is established steady enough that the
outlet (downstream) block valve is fully open, begin
to slowly close the bypass valve if installed.
9. Develop system fl ow to a level near its expected
normal rate, and reset the regulator set point by
turning the adjusting screw (1) CW to increase
outlet pressure, or CCW to reduce outlet pres-
sure.
10. Reduce system fl ow to a minimum level and ob-
serve pressure set point. Outlet pressure will rise
from the set point of Step 9. The maximum rise
in outlet pressure on decreasing fl ow should not
exceed the stated upper limit of the range spring
by greater than 10%. If it does, consult factory.
SECTION IV
SECTION V
increases, the diaphragm pushes up and the port
opening closes.
2. A complete diaphragm failure will cause the reg u-
la tor to fail open and fl uid will discharge from the
spring chamber vent hole.
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve to
about 25% open, observing the outlet (down-
stream) pres sure gauge. Determine if the reg u-
la tor is fl owing. If not, slowly rotate the regulator
ad just ing screw (1) CW (viewed from above) until
fl ow be gins.
CAUTION
Do not walk away and leave a bypassed reg u -
la tor unattended!
VI. SHUTDOWN
1. Shutoff inlet block valve.
2. Allow suffi cient time for the line pressure down-
stream of the inlet block valve to bleed down.
3. Shutoff the outlet block valve.
4. Relieve the trapped upstream and down stream
pres sure.
5. The regulator may now be disassembled for
inspection and pre ven ta tive main te nance while
in-line.