Cashco 345 - Manual (Page 2)

2 IOM-345
III. PRINCIPLE OF OPERATION
SECTION IV
IV. STARTUP
1. Start with the block valves closed. A bypass
valve may be used to maintain outlet pressure
in the downstream system without changing the
fol low ing steps.
2. Relax the range spring by turning the T-bar handle
ad just ing screw counter clockwise (CCW) a mini-
mum of three (3) full revolutions. This reduces the
outlet (downstream) pressure set point.
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 monitor outlet
(down stream) pressure via gauge to assure not
over-pressurizing. NOTE: If no bypass valve is
in stalled, extra caution should be used in starting
up a cold system; i.e. do everything slowly.
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve ob-
serv ing the outlet (downstream) pressure gauge.
Determine if the regulator is fl owing. If not, slowly
rotate the regulator T-bar ad just ing screw handle
clock wise (CW) until fl ow begins.
SECTION V
V. SHUTDOWN
1. On systems with a bypass valve, and where sys-
tem pressure is to be maintained as the regulator
is shut down, slowly open the bypass valve while
closing the inlet (upstream) block valve. Fully
close the inlet (upstream) block valve. (When on
bypass, the system pressure must be constantly
observed and manually regulated.) Close the
outlet (downstream) block valve.
SECTION III
Movement occurs as pressure variations register on the pressure piston. The registering pressure is the outlet, P
2
,
or downstream pressure. The range spring opposes pressure piston movement. As outlet pres sure drops, the range
spring pushes the pressure piston down, opening the port; as outlet pres sure in creases, the pressure piston pushes
up and the port opening closes.
Do not walk away and leave a bypassed regulator unat-
tended!
CAUTION
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 pressure,
close the block valve and go to Step 2, then return
to Step 4.
8. When fl ow is established steady enough that the
outlet (downstream) block valve is fully open, be-
gin 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 T-bar adjusting screw handle CW to
in crease outlet pressure, or CCW to reduce outlet
pressure.
10. Reduce system fl ow to a minimum level and ob-
serve set point. Outlet pressure will rise from the
set point of Step 9. The maximum rise in outlet
pres sure on decreasing fl ow should not exceed the
stated upper limit of the range spring by greater
than 10%; i.e. 500 to1000 psig (34.5 to 68.9 Barg)
range spring, at low fl ow the outlet pressure should
not exceed 1100 psig (75.8 Barg), if it does, consult
factory.
2. If the regulator and system are to both be shut-
down, slowly close the inlet (upstream) block
valve. Close the outlet (downstream) valve only if
regulator re mov al is required.