Cashco POSR-1 User Manual
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
IOM-POSR-1
12-13
MODEL POSR-1
PILOT OPERATED PRESSURE RE DUC ING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The POSR-1 is a pilot operated pressure reducing reg u la tor used to control downstream (P2) pressure. The
POSR-1-20 is a pressure loaded (no pilot) option. Sizes are 1/2", 3/4" and 1" (DN15, 20 and 25). The unit is suitable
for steam service only. Refer to Technical Bulletin POSR-1-TB for design conditions and selection recommendations.
NOT RECOMMENDED FOR DEAD END SERVICE!
SECTION II
II. INSTALLATION
A. General:
WARNING
Do not dead end (no fl ow demand) downstream of POSR-1
if P1 - Inlet Pressure is greater than max i mum allowable
outlet design pressure.
Max. Allowable
Spring Range Out let Pressure
5-15 psig (0.34-1.03 Barg) 100 psig (6.9 Barg)
10-40 psig (0.69-2.8 Barg) 200 psig (13.8 Barg)
30-80 psig (2.1-5.5 Barg) 200 psig (13.8 Barg)
70-150 psig (4.8-10.3 Barg) 200 psig (13.8 Barg)
B. Piping the Valve:
1. An inlet block valve should always be in stalled.
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 are recommended for NPT
screwed in stal la tions to allow removal from
piping.
PI
Pilot
Valve
Main
TR
HP Cond.
Valve
MP/LP Cond.
TR
FIGURE 1
Recommended Piping Schematic for POSR-1
Airset or
Manual Loader
TR
HP Cond.
Main
Valve
Air
Supply
TR
MP/LP Cond.
PI
FIGURE 2
Recommended Piping Schematic for POSR-1-20
CAUTION
SRV
SRV
4. An outlet pressure gauge should be lo cat ed ap prox i mate ly ten pipe diameters down stream,
and within sight.
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.
5. All installations should include a down stream
re lief device if the inlet pressure could ex ceed
the pressure rating of any downstream equip ment or the maximum allowable outlet pres sure
rating of the unit.
6. Clean the piping of all foreign material in clud ing
chips, welding scale, oil, grease and dirt before
installing the regulator. Strainers are recommended.
use 1/4" OD metal tubing for dis tanc es 4 ft
(1.2 m) or less, and 3/8" OD metal tubing (requires 1/4" x 3/8" tubing adapter) for distances
greater than 4 ft. (1.2 m). The sensing line
should always be sloped down ward so that
condensation will drain away from the pilot.
If regulator pipe line is ex pand ing to a larger
pipe line, always connect sens ing line to the
larger pipe line. NOTE: The POSR-1-20 does
not reguire a sensing line.
CAUTION
DO NOT HYDROSTATIC TEST THROUGH AN IN STALLED
UNIT, INCLUDING PILOT; ISOLATE BOTH PILOT AND MAIN
VALVE FROM TEST. The upper range spring pressure
level listed on the nameplate is the rec om mend ed “upper
op er a tive limit” for the sens ing diaphragm(s) in the pilot.
Higher pres sures could cause internal dam age. In addition,
note on the name plate that the Inlet and Outlet pressure
and tem per a ture rat ings are at different levels.
7. In placing thread sealant on pipe ends prior
to en gage ment, assure that excess material
is removed and not allowed to enter the reg u la tor upon start-up.
8. Flow Direction. Install so the fl ow direction
match es the arrow cast on the body.
9. The POSR-1 comes factory piped between
the pilot supply and pilot loading. Install an
external sensing line from the 1/4" NPT con nec tion opposite the factory piped pilot load ing
port to a point downstream at gauge location;
10. For best per for mance Cashco rec om mends
in stall ing regulator in a well drained horizontal
pipe, prop er ly trapped.
11. Recommended installation is with pilot valve
spring chamber vertical upwards. Orient such
that the spring chamber vent hole does not
collect rainwater or debris.
12. Regulators are not to be buried underground.
13. For insulated piping systems, rec om men da tion
is to not insulate regulator.
CAUTION
For welded installations, all internal trim parts, seals and
diaphragm(s) must be removed from reg u la tor body prior
to welding into pipeline. The heat of fusion welding will
dam age non-metallic parts if not re moved. NOTE: This
does not apply to units equipped with extended pipe
nip ples.
III. PRIN CI PLE OF OPERATION
A. General:
1. The POSR-1 pilot obtains its operating
medium from the main valve body inlet.
Down stream pressure (P2) registers on the
un der side of the main valve’s diaphragm and
the pilot valve’s diaphragm(s).
2. The loading pressure on the top side of the
main valve’s diaphragm is an intermediate
pressure higher than the downstream (P2)
pres sure by the sum of the pressures re quired
to overcome the main valve’s plug unbalance
force and the piston spring’s force.
3. The pilot has a bleed orifi ce that continu-
ously bleeds part of the loading medium
down stream. In op er a tion, the pilot valve’s
plug can fl ow more medium than is bleed-
SECTION III
ing down stream. This increases the loading
pres sure on the main valve’s plug and opens
valve. Partially closing the pilot valve’s plug
will reduce its fl ow to less than the amount
bleed ing downstream, and allows the loading
pressure on the main valve’s diaphragm to
de cay, allowing partial closing of the main
valve’s plug. This continues until steady-state
is de vel oped.
4. The pilot valve’s diaphragm(s) senses the
down stream (P2) pressure and compares
the force generated to the force developed
by the pilot’s range spring.
5. If, during operation, the downstream (P2) pres sure falls below the pilot valve’s setpoint, the
main valve’s diaphragm senses the reduced
pres sure on its underside and instantly moves
down, increasing the fl ow through the main
valve. At the same time, the pilot valve
IOM-POSR-12
senses the reduced pressure and the pilot
valve’s plug increases its opening, elevating
the load ing pressure on the upper side of the
main valve’s diaphragm.The combined actions
increase fl ow enough to restore the down-
stream (P2) pressure to the setpoint.
6. If the downstream (P2) pressure rises above the
setpoint, the force developed by the in creased
pressure on the underside of the diaphragm
instantly moves it upward and partially closes
the main valve’s plug. Si mul ta neous ly, the
pilot valve’s plug partially clos es and al lows
SECTION IV
the loading pressure to decay through the
bleed orifi ce. The reduced load ing pres sure
on the upper side of the di a phragm closes
the main valve’s plug enough to re store the
down stream (P2) pressure to the setpoint.
7. Pressure setpoint is adjusted by changing
the com pres sion of the pilot’s range spring
by turning the adjusting screw either clockwise
(CW) or counter-clock wise (CCW). Turning the
adjusting screw clockwise (CW) will in crease
the downstream (P2) pressure. Turn ing the
adjusting screw counter-clockwise (CCW) will
decrease the down stream (P2) pressure.
IV. START-UP
CAUTION
A. General
1. Start with the block valves closed.
2. Ensure that the needle valve(s) on the sens ing
line is opened and downstream (P2) pres sure
is in di cat ing on pressure gauge.
3. Relax the pilot valve range spring by turning
the adjusting screw counter clockwise (CCW)
(viewed from above) a minimum of three (3)
full revolutions. This reduces the outlet (down stream) pressure setpoint.
For POSR-1-20 use manual loading valve to
set minimum loading pressure.
Outlet Pressure - P2
psig (Barg)
5 (0.34) 15 (1.03) 25 (1.7)
50 (3.45) 60 (4.1) 70 (4.8)
100 (6.90) 110 (7.6) 120 (8.3)
130 (8.97) 145 (10.0) 150 (10.3)
135 (9.31) 150 (10.3) – ( – )
Loading Pressure - P3, psig (Barg)
Minimum @ P1 Maximum
@ P
1
4. Slowly open the bypass valve to preheat the
system piping and to allow slow ex pan sion
of the piping. Assure proper steam trap op er a tion. Closely monitor outlet (down stream)
pressure via gauge to assure not over-pres sur iz ing. NOTE: If no bypass valve is in stalled,
extra caution should be used in start ing up a
cold system; i.e. do ev ery thing slowly.
5. Slowly open the outlet (downstream) block
valve until fully open. Slightly close the by pass
valve at same time.
IOM-POSR-1 3
Do not walk away and leave a bypassed reg u la tor unattended when on manual bypass!
6. Slowly open the inlet (upstream) block valve
ob serv ing the outlet (downstream) pres sure
gauge. De ter mine if the reg u la tor is fl owing.
If not, slightly close bypass valve, and then
slowly rotate the pilot valve adjusting screw
clock wise (CW) (viewed from above) until fl ow
begins.
For POSR-1-20 in crease load ing pres sure
until fl ow begins.
CAUTION
Do not exceed Maximum Loading Pressure limits for P2
set point.
7. Continue to alternate slow ly closing the
bypass valve and then slowly opening the inlet
(upstream) block valve, es pe cial ly when the
down stream piping sys tem isn’t pressurized.If
the outlet (downstream) pressure exceeds the
desired pressure, close the bypass valve until fully closed. If outlet pres sure still re mains
above desired level, rotate pilot’s ad just ing
screw CCW (viewed from above) in 1/2
rev o lu tion in cre ments until out let pres sure
reach es de sired level. If outlet pres sure is
below de sired level, ro tate pilot’s ad just ing
screw CW (viewed from above) until de sired
level is reached.
For POSR-1-20 adjust manual loading valve
to either increase or decrease loading pres sure until desired set point is reached. Do not
exceed limits.
8. When fl ow is established steady enough that
the inlet (upstream) block valve is fully open,
begin to slowly close the bypass valve and
continue until fully closed.
9. Develop system fl ow to a level near its ex pect ed
normal rate, and reset the reg u la tor setpoint
by turning the pi lot valve ad just ing screw CW
SECTION V
(viewed from above) to in crease outlet pressure, or CCW to reduce outlet pres sure.
10. Reduce system fl ow to a minimum level and
observe setpoint. Outlet pressure will rise from
the set point of Step 9. There should be no
more than a 10% vari a tion in outlet pres sure
over the max i mum to min i mum fl ow range.
V. SHUTDOWN
A. General
1. On systems with a bypass valve, and where
system pressure is to be main tained as the
POSR-1 is shut down, slowly open the by pass
valve while closing the inlet (up stream) block
valve. Fully close the inlet (up stream) block
valve. (When on by pass, the sys tem pres sure
must be con stant ly ob served and man u al ly
reg u lat ed.) Close the outlet (down stream)
block valve. Close the nee dle valve on the
pilot valve’s sensing line.
SECTION Vl
VI. MAINTENANCE
CAUTION
SYSTEM UNDER PRESSURE. Prior to performing any
maintenance, isolate the regulator from the sys tem and
relieve all pressure. Failure to do so could result in personal injury.
CAUTION
Do not walk away and leave a bypassed reg u la tor unattended when on manual bypass!
2. If the regulator and system are to both be shut down, slowly close the inlet (up stream) block
valve. Close the out let (down stream) valve
only if reg u la tor re mov al is required. Close
the needle valve on the pilot valve’s sensing
line.
For POSR-1-20 close manual loading valve
and relieve loading pressure.
4. All indicated item numbers that are with
respect to the Pilot Valve will be in pa ren the sis and underscored, i.e. (14), (PV). All item
numbers that are with respect to the Main Valve
will NOT be underscored, i.e. (1), (MV).
5. Refer to Figures 3 and 4 for item num ber
callouts.
A. General:
1. Maintenance procedures hereinafter are based
upon removal of the regulator unit from the
pipeline where installed.
2. Owner should refer to owner’s procedures for
re mov al, handling, cleaning and dis pos al of
non-reuseable parts, i.e. gaskets, etc. Cash co
recommends not reusing any gas kets, but replacing with only new and fac to ry supplied
gaskets.
3. This regulator is supplied from the factory
using a gasket sealing aid, Federal Pro cess
Company, PLS 2, or equal. Such compatible
sealing aids may be utilized by the Owner, if
desired.
6. Most pilot-operated valve operation problems
center around the pilot valve (PV). Cashco
always rec om mends full maintenance on any
POSR-1 pilot valve (PV) once a POSR-1 is
removed from the pipeline.
B. Separation:
1. Observe position of pilot valve (PV) with
respect to main valve (MV) before dis as sem bling.
2. Place main valve body (1) into a vise, oriented
to allow rotation of pilot valve (PV) to geth er
with in ter con nect ing pipe nipple (19).
3. Remove loading tubing (21) at both end fi t-
tings (20) by rotating nut CCW (viewed from
tube-end).
IOM-POSR-14