INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
IOM-P7
MODEL P7
PISTON SENSING SINGLE STAGE
PRESSURE REDUCING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model P7 is a 1/2" (DN15) or 3/4" (DN20) pressure reducing regulator used to control downstream (outlet or P2 )
pressure. The unit is suitable for gaseous or liquid services. Refer to Technical Bulletin P7-TB for design conditions
and selection recommendations.
SECTION II
11/13
II. INSTALLATION
CAUTION A
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 regulator 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.
Model P7
7. In plac ing thread seal ant on pipe ends pri or to
en gage ment, ensure that excess material is 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. Regulator may be rotated around the pipe axis 360°.
Recommended position is with spring loaded knob
(38) or loading dome (2) or ratio loading upper case
(44) in ver ti cal upwards position.
11. Regulators are not to be buried un der ground.
12. For insulated piping systems, recommendation is
to not insulate regulator.
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register on the piston (5). The registering pressure
is the outlet, P
range spring (28) or loading pressure (for dome
loaded or ratio loaded designs) opposes piston
, or downstream pressure. The
2
SECTION III
(5) move ment. As outlet pressure drops, the
range spring (28) or loading pressure push es the
piston (5) down, opening the port; as outlet pres sure in creas es, the piston (5) push es up and the
port opening clos es.
2. A complete piston (5) failure will cause the reg u la tor to fail open.
SECTION IV
IV. STARTUP
CAUTION B
For Spring Loaded Design the maximum outlet pressure is indicated 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 piston (see Sec tion IV.
Startup, Step 7).
For Dome & Ratio Loaded Design the max outlet pressure is 1500 psig (103.4 barg).
Max loading pressure for Ratio Loaded Design is 105
psig (7.2 barg).
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 range spring (28) by turning the knob (38)
counter clockwise (CCW) until ro ta tion comes to
a complete stop; or remove the loading pressure
for dome loaded or ratio loaded designs.
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.
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 the regulator knob (38) clock wise (CW) or
increase the loading pressure 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, reset the regulator set point by turning
the knob (38) (CW) to increase outlet pressure or
(CCW) to reduce outlet pressure. Adust the loading pressure for dome or ratio loaded designs.
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 (28) by
greater than 10%; i.e. 2-100 psig (.14-6.9 Barg)
range spring (28).
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 lat ed. Close the
outlet (down stream) block valve.
SECTION V
2. If the regulator and system are to both be shut
Do not walk away and leave a bypassed
regulator unattended.
down, slowly close the inlet (upstream) block
valve. Close the outlet (downstream) valve only
if reg u la tor re mov al is required.
CAUTION C
IOM-P72
SECTION VI
VI. MAINTENANCE
WARNING 1
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. Apply a thin coat of Christo Lube to all o-rings.
4. Refer to Figure 1, Figure 2 or Figure 3 for pertinent design.
CAUTION D
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.
5
WARNING 2
SPRING UNDER COMPRESSION. Prior to re mov ing
spring chamber, relieve range spring com pres sion
by turn ing the knob counter clock wise (CCW) until
ro ta tion comes to a com plete stop. For DOME or
RATIO Loaded remove all loading pressure. Fail ure
to so may result in fl ying parts that could cause
personal injury.
B. Poppet Seat & Piston Replacement - Spring
Loaded Vented Design:
1. Securely install the body (1) in a vise with the
spring knob (38) directed upwards.
2. Relax range spring (28) by turning the knob (38)
counter clockwise (CCW) until rotation comes
to a complete stop. NOTE: It is not necessary
to remove the knob (38) before removing the
spring chamber(2)-(upper assembly) from the
body (1). Remove upper assembly by turning-
spring chamber (2) (CCW). Lift upper assembly
off of range spring (28).
3. Remove spring (28), pin (40) and spring follower
(26).
4. Grab vent cap (25) by fl ats and pull up to remove
piston (5) and sleeve (3) from body (1). Remove
and replace o-ring (4).
5. With thumb, press down on top of vent cap (25)
to separate piston (5) from sleeve (3). Remove
and replace o-ring (6).
6. Secure piston (5) in a vise using the fl ats on
the sides of piston. Remove vent cap (25) by
turning (CCW).
7. Use a pair of needle nose pliers to grasp top of
poppet (23). Pull upwards to remove poppet,
poppet seat (24) and poppet spring (22).
8. Reinstall poppet spring (22) and poppet (23) in
piston (5). Slide new poppet seat / disc (24)
over poppet. Install vent cap (25) on piston (5),
use (CW) rotation to tighten metal to metal.
9. Insert smallest o.d. of piston (5) into largest i.d.
of sleeve (3). Press tighly together for metal to
metal contact. Press this assembly into body
(1); vent cap (25) oriented upwards.
10. Place spring follower (26) with smallest o.d.
next to piston. Install spring (28).
11. Place upper spring chamber assembly on body
(1). Turn spring chamber (2) (CW) to secure
tight to body. Remove knob cover (39).
12. Rotate vent screw (36) CCW to remove screw
and spring (35). Record number of revolutions.
for removal of screw. _________
13. Lower pin (40) through top / center of adjusting
screw (34), pin should rest on top of poppet (23).
NOTE: insert a small diameter tool through
center of adjusting screw and carefully press
downward on pin (40) to confi rm recoil of the
poppet spring (22).
14. Install spring (35) and vent screw (36) - recalling
the number of revolutions counted for removal
from above. Reinstall knob cover.
C. Piston Replacement - Spring Loaded
Non-Vented Design:
1. Instructions are similar to Vented with exception: Assembly does not include pin (40), per
B. 3, the poppet, (23) and poppet spring (22).
per B.7 & B.8. The poppet seat (24) is replaced
by a solid disc.
IOM-P7
3
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