Cashco 6987 - Manual (Page 2)

IOM-6987 2
SECTION IV
10. Basic Regulator- (See Figure 1): Regulator may
be rotated around the pipe axis 360°. Rec om -
mend ed po si tions are with spring cham ber
ver ti cal upwards, or hori zon tal. Orient such that
the spring chamber vent hole does not collect
rain wa ter or debris.
11. Regulators are not to be direct buried un der -
ground.
12. For insulated piping systems, rec om men da tion is
to not in su late reg u la tor.
SECTION III
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations reg-
is ter on the diaphragm. The registering pressure
is the inlet, P
1
or upstream pressure. The range
spring opposes dia phragm move ment. As inlet
pressure drops, the range spring pushes the dia-
IV. STARTUP
7. Observing the inlet (upstream) pressure gauge,
ro tate the ad just ing screw clockwise (CW) slowly
until the inlet pressure begins to rise. Rotate CW
until the desired setpoint is reached.
8. Continue to slowly open the inlet (upstream) block
valve. If the inlet (upstream) pressure ex ceeds
the desired set point pressure, rotate the adjusting
screw CCW until the pressure decreases.
9. When fl ow is established steady enough that both
the outlet and inlet block valves are fully open, be-
gin to slowly close the bypass valve if installed.
10. Develop system fl ow to a level near its expected
normal rate, and reset the regu la tor set point by
turning the ad just ing screw CW to increase inlet
pressure, or CCW to reduce inlet pressure.
11. Reduce system fl ow to a minimum level and ob-
serve set point. Inlet pressure will rise from the
setpoint of Step 9. (Ensure that this rise does not
exceed the stated upper limit of the range spring
by greater than 50%, i.e. 50 - 100 psig (3.4 - 6.9
Barg) range spring, at maximum fl ow the inlet
pressure should not ex ceed 1.5 x 100 psig (6.9
Barg), or 150 psig (10.3 Barg). If it does, consult
factory.)
12. Increase fl ow to maximum level if possible. Inlet
(up stream or P
1
) pressure should fall off. Readjust
setpoint as necessary at the normal fl ow rate.
1. Start with the block valves closed. A bypass valve
may be used to maintain inlet pressure in the
up stream system without chang ing the following
steps.
2. Relax the range spring by turning the adjusting
screw counterclockwise (CCW) a minimum of
three (3) full revo lu tions. This reduces the inlet
(upstream) pres sure setpoint.
3. If it is a “hot” piping system, and equipped with
a bypass valve, slowly open the bypass valve
to pre-heat the system piping and to allow slow
ex pan sion of the piping. Closely mon i tor inlet
(up stream) pres sure, via gauge, to assure not
over-pres sur iz ing. NOTE: If no bypass valve is
in stalled, extra caution should be used in starting
up a cold system; i.e. do ev ery thing slowly.
4. Crack open the inlet (upstream) block valve.
5. Slowly open the outlet (downstream) block valve
ob serv ing the inlet (upstream) pressure gauge.
De ter mine if the regulator is fl owing. If not, slowly
rotate the regulator adjusting screw counter clock -
wise (CCW) until fl ow be gins.
6. Continue to slowly open the outlet (down stream)
block valve until fully open.
phragm down, closing the port; as inlet pressure
in creases, the dia phragm pushes up and the port
opens.
2. A complete diaphragm failure may cause the
valve to fail closed.
WARNING
The maximum inlet pressure is equal to 1.5 times the larger
number of the stated range spring on the name plate, and is
the recommended “upper operative limit” for the sens ing
di a phragm. Higher pressures could damage the di a phragm.
(Field hy dro stat ic tests fre quent ly destroy di a phragms.
DO NOT HY DRO STAT IC TEST THRU AN IN STALLED UNIT;
ISOLATE FROM TEST.)