Cashco 1000 Cryogenic - Manual (Page 3)

IOM-1000HP-Cryogenic 3
SECTION IV
VI. MAINTENANCE
A. General:
1. Maintenance procedures hereinafter are
based upon removal of the regulator unit
from the pipeline where in stalled.
2. Owner should refer to owner's proce dures for
removal, handling and cleaning of re use able
parts, and disposal of non reuseable parts, i.e.
asbestos gaskets, suitable sol vents, etc.
IV. STARTUP
1. Purge the system, including the spring cham ber,
to remove air, moisture, carbon dioxide, etc.
2. 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.
3. Relax the range spring by turning the adjusting
screw counterclockwise (CCW) a min i mum of
three (3) full revolutions. This re duces the outlet
(down stream) pres sure set point. NOTE: Ro ta-
tion CW or CCW is as viewed from the ad just ing
screw end, i.e. bottom of valve looking up.
4. If equipped with a bypass valve, slowly open the
bypass valve to cool the system piping and to al-
low slow contraction of the piping. Closely monitor
outlet (down stream) pressure via gauge to ensure
not over-pres sur iz ing. NOTE: If no bypass valve
is in stalled, extra caution should be used in start-
ing up an am bi ent tem pera ture system; i.e. do
everything slow ly.
5. Crack open the outlet (downstream) block
valve.
6. Slowly open the inlet (upstream) block valve ob-
serv ing the outlet (down stream) pres sure gauge.
SECTION V
V. SHUTDOWN
1. On systems with a bypass valve, and where sys-
tem pressure is to be maintained as the reg u la tor
is shut down, slowly open the by pass valve while
clos ing the inlet (up stream) block valve. Fully
close the inlet (up stream) block valve. (When on
bypass, the system pres sure must be con stant ly
observed and man u al ly reg u lat ed.) Close the
outlet (down stream) block valve.
2. If the regulator and system are to both be shut-
down, slowly close the inlet (upstream) block
valve. Close the outlet (down stream) valve only
if regulator re mov al is required.
SECTION VI
Determine if the regulator is fl owing. If not, slowly
rotate the reg u la tor ad just ing screw clockwise
(CW) until fl ow begins.
7. Continue to slowly open the inlet (up stream) block
valve until fully open.
8. Continue to slowly open the outlet (down stream)
block valve, especially when the down stream pip-
ing system isn't pres surized. If the outlet (down-
stream) pressure exceeds the de sired pres sure,
close the block valve and go to Step 2, then return
to Step 4.
9. 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 in stalled.
10. Develop system fl ow to a level near its expected
normal rate, and reset the regulator set point by
turning the adjusting screw CW to increase outlet
pressure, or CCW to reduce outlet pres sure.
11. 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
pressure on decreasing fl ow should not exceed
the stated up per limit of the range spring by
greater than 30%; i.e. 10-40 psig range spring, at
low fl ow the outlet pressure should not exceed 52
psig. If it does, consult fac to ry.
CAUTION
Do not walk away and leave a bypassed regulator unat-
tended.