Cashco P2 User Manual
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
MODEL P2
SINGLE STAGE CYLINDER GAS
PRESSURE REDUCING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model P2 is a pressure reducing regulator used to control downstream (outlet or P2 ) pressure. Available sizes
inlet/outlet port - 1/4" (DN8), 3/8" (DN10) and 1/2" DN15. The unit is suitable for cylinder gaseous service. Refer
to Technical Bulletin P2-TB for design conditions and selection recommendations.
SECTION II
IOM-P2
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II. INSTALLATION
CAUTION
Installation of adequate overpressure pro tec tion
is recommended to pro tect the reg u la tor from
over pres sure and all down stream equip ment from
dam age in the event of reg u la tor failure.
1. An inlet block valve should always be installed.
2. If service application is continuous such that
shut down is not readily accomplished, it is recommended that an inlet block valve, outlet block
valve, and a manual bypass valve be installed.
3. Pipe unions should be installed to allow removal
from piping.
4. An outlet pressure gauge should be located ap proxi mately ten pipe diameters downstream, and
within sight.
5. All installations should include a downstream re lief de vice if the inlet pressure could exceed the
pres sure rating of any downstream equip ment or
the maximum outlet pressure rating of the unit.
6. Clean the pip ing of all foreign material including
chips, welding scale, oil, grease and dirt before
installing the reg u la tor. Strainers are rec om mend ed.
7. In plac ing thread seal ant on pipe ends pri or to
en gage ment, ensure that excess material is
Supply
@P
1
Model P2
Reducing
Regulator
Blowdown-Drain
Recommended Piping Schematic
For Pressure Reducing Station
SRV
Bypass
Blowdown-Drain
Outlet
@P
2
re moved and not allowed to enter the regulator
upon startup.
8. Flow Direction: Install so the fl ow direction match-
es the inlet stamp on the main regulator body (1).
9. For best performance, install in well drained hori zon tal pipe.
10. Basic Regulator - (Refer to Figure 2, Model P2):
Regulator may be rotated around the pipe axis
360°. Recommended position is with aluminum
knob (4) ver ti cal upwards.
11. Regulators are not to be buried un der ground.
12. For insulated piping systems, recommendation is
to not insulate regulator.
P
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III. PRINCIPLE OF OPERATION
SECTION III
1. Movement occurs as pressure variations register
on the diaphragm (7.1). The registering pressure
is the outlet, P2, or downstream pressure. The
range spring (15) opposes diaphragm move ment. As outlet pressure drops, the range spring
push es the diaphragm down, opening the port; as
SECTION IV
IV. STARTUP
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.)
1. Start with the block valves closed. A by pass
valve may be used to maintain out let pres sure
in the down stream sys tem without changing the
fol low ing steps.
2. Relax the range spring (15) by turning knob (4)
counter clockwise (CCW) until ro ta tion comes to
a complete stop.
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) pres sure via gauge to ensure 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.
outlet pres sure in creas es, the diaphragm push es
up and the port opening clos es.
2. A complete diaphragm failure will cause the reg u la tor to fail open.
5. Slowly open the inlet (upstream) block valve ob serv ing the outlet (downstream) pressure gauge.
De ter mine if the regulator is fl owing. If not, slowly
rotate knob (4) clock wise (CW) until fl ow begins.
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 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 knob (4) CW to increase 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
pressure on decreasing fl ow should not exceed
the stated up per limit of the range spring by greater
than 10%. Example: with 2-100 psig (.14-6.9 Barg)
range spring at low fl ow the outlet pressure should
not exceed 110 psig (7.6 Barg), if it does, con sult
factory.
V. SHUTDOWN
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
outlet (down stream) block valve.
2
lat ed. Close the
SECTION V
CAUTION
Do not walk away and leave a bypassed
regulator unattended.
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 reg u la tor re mov al is required.
IOM-P2
VI. MAINTENANCE
WARNING
SYSTEM UN DER PRES SURE. Prior to per form ing
any maintenance, isolate the reg u la tor from the
sys tem and relieve all pres sure. Failure to do so
could result in personal injury.
A. General:
1. Maintenance procedures hereinafter are
based upon re mov al of the regulator unit from
the pipeline where in stalled.
2. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of
non reuseable parts, i.e. gaskets, etc.
3. Refer to Figure 2 for basic reg u la tor and Figure 1 for the diaphragm sub as sem bly.
B. Diaphragm Replacement:
CAUTION
To prevent damage to body, use soft jaws when
placing body in a vise. Position so that vise
closes over the fl ats on lower end of body.
WARNING
5
SPRING UNDER COMPRESSION. Prior to removing spring chamber, relieve range spring
com pres sion by turn ing knob (4) CCW until
ro ta tion comes to a com plete stop. Fail ure to
so so may result in fl ying parts that could cause
personal injury.
1. Securely install the body (1) in a vise with
knob (4) directed upwards.
2. Relax range spring (15) by turning knob (4)
CCW until rotation comes to a complete stop.
NOTE: It is not necessary to remove knob
before removing the spring chamber (6) from
the body (1).
SECTION VI
Figure 1: Diaphragm Subassembly
(7.1), ac tu a tor post (7.2), ac tu a tor gasket
(7.4), ac tu a tor o-ring (7.5). Remove di a phragm gas ket (10).
5. Remove actuator nut (7.3) and separate all
parts of the diaphragm subassembly (7).
6. Clean body (1) diaphragm fl ange and all re us-
able parts according to owner's procedures.
Do not scratch di a phragm gas ket seat ing
sur face. NOTE: On reg u la tors origi nally
sup plied as “oxygen clean”, Option-M, maintenance must in clude a level of clean li ness equal to Cash co's clean ing stan dard
#S-1134. Contact factory for details.
7. Inspect and replace any necessary parts.
NOTE: Use only parts man u fac tured and
sup plied by Cashco, Inc. for these products.
See Section VIII.
8. Reassemble di a phragm subassembly (7) by
plac ing the actuator gasket (7.4), di a phragm
(7.1), and actuator o-ring (7.5) over the
threads of the actuator post (7.2). Place a
thread sealant com pound on the threads of
the ac tu a tor post (7.2) prior to installing the
actuator nut (7.3). Install ac tu a tor nut (7.3)
and tighten to the fol low ing torque value: 15
Ft-lbs (20 Nm).
9. Place the diaphragm gas ket (10) onto the
body (1) diaphragm fl ange. Place di a phragm
subassembly on top of the gasket (10).
IOM-P2
3. Remove spring chamber subassembly by
grasping the fl ats and turning CCW. Upon
removal, the range spring (15), range spring
clip (16), and spring button (5) should remain
inside the spring cham ber.
4. Remove diaphragm subassembly (7) con sist ing of the actuator nut (7.3), diaphragm
10. Lubricate the threads of the body (1) with
a light weight grease that is compatible with
service use. Ro tate the spring chamber (6)
CW by hand onto the threaded portion of
the body (1) until fi rmly seated against the
diaphragm gasket (10). Tighten to the fol
ing torque val ue: 65–70 Ft lbs (88–95 Nm).
low-
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