Cashco B2 - Manual (Page 2)

IOM-B2 2
SECTION IV
IV. STARTUP
SECTION V
V. SHUTDOWN
SECTION III
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register on
the diaphragm. The registering pressure is the inlet,
P
1
, or upstream pressure. The range spring opposes
diaphragm movement. As inlet pressure drops, the
range spring pushes the dia phragm down, closing
the port; as inlet pres sure in creas es, the diaphragm
pushes up and the port opens.
2. A complete diaphragm failure will cause the reg u la tor
to fail closed.
1. Start with the block valves closed. A bypass valve may
be used to maintain inlet pressure in the upstream
system without changing the fol low ing steps.
2. Relax the range spring (15) by turning knob (4) counter
clockwise (CCW) a minimum of three (3) full rev o lu-
tions. This reduces the inlet (up stream) 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. Assure proper steam trap operation if
installed. Closely monitor inlet (up stream) pres sure
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 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 CCW until fl ow begins.
6. Continue to slowly open the outlet (downstream)
block valve until fully open.
7. Observing the inlet (upstream) pressure gauge,
ro tate knob (4) clockwise (CW )slowly until the inlet
pres sure 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 exceeds the
desired setpoint pressure, rotate knob (4) CCW until
the pres sure decreases.
9. When fl ow is established steady enough that both
the outlet and inlet block valves are fully open, begin
to slowly close the bypass valve, if installed.
10. Develop system fl ow to a level near its expected
normal rate, and reset the regulator setpoint by turn-
ing knob (4) CW to increase inlet pressure, or CCW
to reduce inlet pressure.
11. Using a downstream valve, reduce system fl ow to a
min i mum level and ob serve setpoint. Inlet pres sure
will rise from the setpoint of Step 9. (Ensure this rise
does not exceed the stated upper limit of the range
spring by greater than 50%, i.e. 2-50 psig (.14 - 3.4
Barg) range spring, at maximum fl ow the inlet pres-
sure should not exceed 1.5 x 50 psig (3.4 Barg), or
75 psig (5.2 Barg). If it does, consult factory).
12. Increase fl ow to maximum lev el, if possible. Inlet
(up stream or P
1
) pressure should fall off. Re ad just
setpoint as necessary at the normal fl ow rate.
1. On systems with a bypass valve, and where sys tem
pressure is to be main tained as the reg u la tor is shut
down, slowly open the bypass valve while closing the
inlet (up stream) block valve. Fully close the inlet (up-
stream) block valve. (When on bypass, the sys tem
pres sure must be con stant ly observed and man u al ly
reg u lat ed. Close the outlet (down stream) block
valve.
CAUTION
The maximum outlet pressure is stamped on the
body as the upper range spring pres sure level, and
is the rec om mend ed “upper operative limit” for the
sens ing diaphragm (see Sec tion IV. Startup, Step
7). Higher press ures could dam age the di a phragm.
(Field hydro static tests fre quent ly de stroy di a -
phragms. DO NOT HYDRO STATIC TEST THRU AN
IN STALLED UNIT; ISO LATE FROM TEST.)
CAUTION
Do not walk away and leave a bypassed regulator
unattended.