Cashco PGR-1 User Manual
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
IOM-PGR-1
MODEL PGR-1
DIRECT-ACTING, PRESSURE LOADED
PRESSURE REDUCING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
Model PGR-1 is a pressure reducing regulator used to control downstream (outlet or P2) pressure. Sizes are
1/2" (DN15), 3/4" (DN20), 1" (DN25), 1-1/2" (DN40), 2" (DN50), 3" (DN80) and 4" (DN100). This model is applied
primarily in gaseous service.
SECTION II
03-14
II. REFERENCES
Refer to Technical Bulletin PGR-1-TB for tech ni cal
specifi cations for this reg u la tor.
SECTION III
III. INSTALLATION
1. Regulator may be rotated around pipe axis 360
degrees. For ease of maintenance, the rec om mend ed position is with the cover dome (2)
up wards.
2. Provide space below, above, and around reg u la tor for removal of parts during maintenance.
3. Install block valves and pressure gauges to pro vide means for adjustment, operation, bypass,
or removal of the regulator. A pipeline strainer
is recommended before inlet to remove typical
pipe line debris from entering valve and damaging
internal “soft goods”, primarily the dynamic seal.
ABBREVIATIONS
CW – Clockwise
CCW – Counter Clockwise
ITA – Inner Trim Assembly
CAUTION
Installation of adequate overpressure pro tec tion is recommended to pro tect the reg u la tor from overpressure and
all down stream equip ment from damage in the event of
regulator failure.
Model PGR-1
SECTION IV
CAUTION
DO NOT HYDROSTATIC TEST THROUGH AN IN STALLED
UNIT; ISOLATE REGULATOR FROM TEST. The "OUTLET
RATING" as printed on the name plate is the rec om mend ed
“upper op er at ing limit” for the sens ing di a phragm. Higher
pres sures could cause internal dam age. In ad di tion, note
on the nameplate that the Inlet and Outlet pres sure and
temperature ratings are at different levels.
IV. PRINCIPLE OF OPERATION
1. When a loading pressure – P
the top side of a diaphragm, the outlet controlled
pressure – P
– will balance at approximately
2
.90 – .98 of the loading pressure - PL.
– is applied to
Load
SECTION V
V. STARTUP
1 Start with the block valves closed.
2. Movement occurs as pressure variations register
on the diaphragm. The registering pressure is the
outlet, P
, or downstream pressure. The loading
2
pressure fl uid op pos es di a phragm move ment.
As outlet pres sure drops, the loading pressure
push es the di a phragm down, opening the port; as
outlet pres sure increases, the diaphragm pushes
up and the port opening closes.
3. A diaphragm failure will tend to cause the reg u la tor
to fall below setpoint. A loss of loading pres sure
while inlet pressure is imposed will cause the
regulator to fail close.
pressure upwards until the main valve is fl owing.
Observe the outlet pressure gauge to ensure not
overpressurizing.
CAUTION
Do not walk away and leave a bypassed reg u la tor unattended!
2. Rotate the adjusting screw (47) on the pilot valve
CCW so that main regulator is trying to be con trolled
at 0 psig pressure. DO NOT rotate the adjusting
screw on the stabilizer, stabilizer was preset and
calibrated at the factory.
3. DO NOT rotate knob on metering valve, it was
preset at the factory at 2.5 to 3 full revolutions from
closed position. DO NOT close metering valve.
4. 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) pressure 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.
5. Crack open the outlet (downstream) block valve
to approximately 10% full open.
6. Slowly open the inlet (upstream) block valve to
about 25% open. Rotate the adjusting screw
(47) on the pilot valve CW to increase setpoint
7. Continue to slowly open the inlet (upstream) block
valve until fully open.
8. Continue to slowly open the outlet (downstream)
block valve, especially when the downstream piping system isn’t pressurized. If the outlet (down stream) pressure exceeds the desired pres sure,
close the inlet block valve and go to Step 2. Close
bypass valve approximately 25%, and re peat
pro ce dure.
9. When fl ow is established steady enough that the
outlet (downstream) block valve is 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 set point by
rotating the adjusting screw (47) on the pilot valve
CW to change the setpoint to the desired outlet
pressure level. If system pressure is unstable
rotate knob on metering valve in quarter turn increments CW or CCW to combat instability. DO
NOT rotate knob more than 6 full revolutions from
the closed position.
11. Reduce system fl ow to a minimum level and
observe pressure set point. Outlet pressure will
rise from the set point of Step. The max i mum rise
in outlet pres sure on de creas ing fl ow should not
exceed the 10%. If it does, consult factory.
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IOM-PGR-1
VI. SHUTDOWN
1. Shutoff inlet block valve.
SECTION VI
4. Relieve any trapped upstream and downstream
pressure and loading pres sure from PGR-1.
2. Allow suffi cient time for the line pressure down-
stream of the inlet block valve to bleed down.
3. Shutoff the outlet block valve.
SECTION VII
VII. MAINTENANCE
WARNING
SYSTEM UNDER PRESSURE. Prior to per form ing any
maintenance, isolate the reg u la tor from the system and
relieve all pressure. Failure to do so could result in personal injury.
A. General:
1. The main regulator body may be serviced
without re mov ing the regulator from pipeline.
The reg u la tor is designed with quick-change
trim to simplify maintenance.
2. Record the name plate information to req-
ui si tion repair parts for the regulator. This
in for ma tion should include: Serial Number
and Product Code.
5. The regulator may now be removed from the
pipe line or disassembled for inspection and pre ven ta tive main te nance while in-line.
Item Dynamic
No. Seal Type Part Description
4 .......................All....................................................Cage
5........................All......................................................Plug
9 ......................All .....................................Guide Bearing
10......................All......................................................Seat
13 .....................All ................................. Static Stem Seal
13.1 ............... All ...................... Upper Static Stem Seal
13.2 ............... All ......................Middle Static Stem Seal
13.3 ............... All ...................... Lower Static Stem Seal
14 ......................All..................................Cage O-ring Seal
15......................OR...........................Dynamic O-ring Seal
15.1...............UC............................Dynamic U-cup Seal
15.2............... UC.......................................Seal Retainer
B. Main Valve Disassembly:
1. Shut down system in accordance Section
VI.
2. Disconnect the external sensing line from
the pilot valve sensing port.
3. Refer to Section IX for recommended repair
parts. Only use original equipment parts
sup plied by Cashco for re build ing or re pair ing reg u la tors.
4. Owner should refer to owner's procedures
for removal, handling, cleaning and disposal
of nonreuseable parts, i.e. gaskets, etc.
NOTE: On regulators originally supplied as
“special clean” – Opt-56, maintenance must
include a level of cleanliness equal to Cashco
cleaning standard #S-1542.
5. The Inner Trim is re moved and replaced back
in the body (1) as an assemblage of parts.
The Inner Trim Assembly, here in af ter called
ITA, consists of following parts: (See Figure
1)
A detailed view of the dynamic side seal
parts is shown on page 5.
3. Though it is possible to disassemble the
valve unit while installed in a pipeline, it is
rec om mend ed that all maintenance be done
in a shop. The instructions hereafter will assume in shop disassembly. Remove valve
from pipeline.
4. Place the main valve unit in a vise with the
cover dome (2) upwards.
5. Loosen all fi tings and remove tubing that
connect the inlet fi lter to the stablizer, the
cover dome to the metering valve and the
outlet of the metering valve to the outlet of
the body.
6. Loosen and remove the two nuts (24) that
secure the mounting bracket (3) and pilot to
the cover dome (2). Set pilot assembly aside.
Place match marks on the cover dome fl ange
to mark the location for the mounting bracket
and two longer bolts (23).
IOM-PGR-1
3
7. Loosen the diaphragm fl ange bolts (23) and
nuts (24) uniformly and remove.
8. Place matchmarks on body (1) and cover
dome (2) fl anges. Remove cover dome.
9. With wrench grasp and hold the milled “fl ats”
on top of the valve plug (5) stationary. Rotate
di a phragm nut (11) CCW and remove .
10. Remove upper diaphragm plate (7).
11. Remove diaphragm (6) and o-ring upper stem
seal (13). Examine diaphragm to determine
whether failed; determine if op er at ing conditions are ex ceed ing pressure, pressure drop
or temperature limits.
12. Re move lower diaphragm pusher plate (8).
13. Rotate the cage bolts (22) CCW evenly in single
revolution increments. Regulator con tains a
lower return spring (18); the ITA should rise
up as the cage cap screws are evenly backed
out. A down wards holding force should be
ap plied to the top of the guide bearing (9) to
pre vent the ITA from pop ping up as the last
threads of the cage bolts are backed out.
14. Remove the ITA by pulling up on the valve
plug (5). Set ITA aside.
d. Examine the com po nent(s) (15 or 15.1,
15.2) of the dy nam ic side seal to de ter mine if sig nifi cant leakage was oc cur ring.
If the dy nam ic side seal shows signs of
sig nifi cant leakage, de ter mine if op er at-
ing con di tions are ex ceed ing pres sure,
pres sure drop, or tem per a ture limits.
Remove dynamic side seal com po nents.
Special care should be taken when using “tools” to remove the components to
ensure that no scratches are imparted
to any portion of the guide bearing (9)
groove.
e. Remove o-ring lower stem seal (13) from
plug (5).
f. Remove seat (10); examine for signs of
leakage. If seat ring shows signs of signifi cant leakage, determine if op er at ing
con di tions of pressure, pressure drop, or
temperature are ex ceed ing limits.
913
15
14
4
15. Remove the lower return spring (18) from
within the body (1) cavity.
16. Remove cage o-ring seal (14). It may have
been removed when the ITA was lifted out of
the body.
17. Remove internal sensing drilled plug (19) using 5/32" (4 mm) allen wrench.
18. Remove body (1) from vise. Clean all re us able
metal parts according to owner's pro ce dures.
C. Disassembly of the ITA:
1. See Figure 1 for details:
a. While holding the cage (4) pull the valve
plug (5) down wards and thru of the guide
bear ing (9) and out the bottom of the cage.
b. Remove the guide bearing (9) from the
upper end of the cage (4).
c. Remove o-ring middle stem seal (13) from
guide bearing (9).
5
10
Figure 1: Assembled ITA,
D. Inspection of Parts:
1. After inspection remove from the work area
and dis card the old “soft goods” parts (i.e. orings, di a phragms, seals, gaskets, etc.) after
in spec tion. These parts MUST be re placed
with fac to ry supplied new parts.
2. Inspect the metal parts that will be reused. The
parts should be free of surface con tam i nants,
burrs, oxides, and scale. Rework and clean
parts as necessary. Surface con di tions that
affect the regulator performance are stated
below; replace parts that can not be re worked
or cleaned.
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IOM-PGR-1
3. QC Requirements:
a. Valve plug (5);
1. 16 rms fi nish on its seating surface
for tight shutoff.
2. No major defects on bottom guide
spin dle.
b. Cage (4);
1. 16 rms fi nish on cylinder bore. No
“ledges” formed due to wear from
moving dynamic side seal (27) or
wiper seal (16).
c. Lower guide bushing (24) (non-re place-
able):
1. 16 rms fi nish on bore.
2. Max 0.015 inch (0.38 mm) clearance
be tween valve plug (20) spindle and
lower guide bushing (24).
d. Internal sensing drilled plug (32);
1. Ensure that bore is minimum 0.125
inch (3.20 mm). Drill out as required.
4. Staging Material for Reassembly.
a. Inspect and clean parts, as necessary,
from the spare parts kit. (See Article VII
A.4. comments concerning special cleaning.
b. Lay out all the regulator parts and check
against the bill of material.
E. Reassembly of the ITA:
1. Installation of dynamic side seal (15).
a. Type OR:
1. Stretch o-ring seal (15) over lower
cir cum fer ence of guide bear ing (9),
tak ing care not to “cut” o-ring seal.
Using thumbs, work the o-ring seal
up and into the groove of the guide
bearing. NOTE: A very slight amount
of fl uid and elas tomer compatible
lu bri cant is rec om mend ed as an
in stal la tion aid.
2. Position guide bearing (9) over top
of the upper end of cage (4) properly
oriented. Using thumbs, evenly press
guide bearing into the cage, ensuring not to “cut” o-ring seal. Continue
pressing guide bearing into cage until
in ap prox i mate fi nal position.
b. Type UC:
1. Stretch u-cup seal (15.1) over lower
circumference of guide bear ing (9),
taking care not to “cut” u-cup seal on
the protruding shelf that is part of the
guide bear ing's groove. Ensure that
the u-cup seal is oriented with the
center-open-downwards as shown
in image below, as the u-cup seal
depends upon the P1-Inlet Pres sure
to pressure activate the seal for proper
sealing action.
2. Position guide bearing (9) over top
of the upper end of cage (4) properly oriented, until the cup seal edge
touches the upper lip of the cage
(4). While gently applying force to
press the guide bearing (9) into the
cage, simultaneously use fi ngers to
lightly press the edges of the u-cup
seal inwards into the groove of the
guide bearing until the u-cup seal
(15.1) “slips into” the cage (19). DO
NOT USE TOOLS, LUBRICANT, OR
HEAVY FORCE TO ENGAGE THE
U-CUP SEAL INTO THE CAGE .
IOM-PGR-1
Type OR — O-Ring
Dynamic Seal
Type UC — U-Cup
Dynamic Seal
5
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