cashco 1171 Instruction manual

MODELS 1171 AND 2171
BACK PRESSURE / RELIEF REGULATORS
SECTION I
I. DESCRIPTION AND SCOPE
The instructions in this manual will refer to both models, unless otherwise stated.
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-1171/2171
02-16
SECTION II
Recommended Piping Schematic For Back Pressure/Relief Station
Models 1171/2171
BP/Relief Regulator
Models 1171 and 2171 are back pressure/relief regulators used to control upstream (inlet or P1) pressure. Sizes are
1/4", 3/8" and 1/2" (DN8, DN10 and DN15). The 1171 is a bronze bodied unit; the 2171 incorporates a stainless steel
body. With proper trim utilization, both units are suitable for liquid, gaseous and steam service (the 2171 can also
be used with various chemicals). Refer to Technical Bulletins 1171-TB and 2171-TB for specific design conditions
and selection recommendations.
1. An inlet block valve should always be installed.
2. If service application is continuous such that
shutdown is not readily accomplished, it is rec-
ommended 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 inlet pressure gauge should be located
approximately ten pipe diameters upstream, and
within sight. An outlet pressure gauge is optional.
II. INSTALLATION
5. All installations should include an upstream relief
device if the inlet pressure could exceed the
pressure rating of any equipment or the maximum
inlet pressure rating of the unit.
6. Clean piping of all foreign material including chips,
welding scale, oil, grease and dirt before installing
the regulator. Strainers are recommended.
7. In placing thread sealant on pipe ends prior to
engagement, assure that excess material is
removed and not allowed to enter regulator upon
startup.
Supply
@ P1
SRV System
P1
P1
P2
Discharge
CAUTION
For welded installations, all internal trim parts, seals and
diaphragm(s) must be removed from regulator body prior
to welding into pipeline. The heat of fusion welding will
damagenon-metallicpartsifnotremoved. NOTE:Thisdoes
not apply to units equipped with extended pipe nipples.
CAUTION
This is not a safety device and must not be substituted for a code
approved pressure safety relief valve or rupture disc.
CAUTION
The maximum inlet pressure is equal to 1.5 times the
larger number of the stated range spring on the name-
plate, and is the recommended "upper operative limit" for
the sensing diaphragm. Higher pressures could damage
the diaphragm. (Field hydrostatic tests frequently destroy
diaphragms. DO NOT HYDROSTATIC TEST THRU AN
INSTALLED UNIT; ISOLATE FROM TEST.)
ISO Registered Company

2 IOM-1171/2171
8. Install so the flow direction matches the arrow
cast on the body. Connect the inlet pressure
to the body side connection(s). Fluid will relieve
out of the bottom connection. The double inlet
connections are for in-line installation (plug
one side connection if in-line installation is not
required).
9. Regulator may be installed in a vertical or
horizontal pipe. If it is a steam system, assure
the piping is properly trapped and oriented.
10.A. Basic Regulator - (Refer to Figure 1, Model 1171
or 2171): Regulator may be rotated around the
pipe axis 360°. Recommended position is with
spring chamber vertical upwards. Orient such
that the spring chamber vent hole does not collect
rainwater.
10.B. Cryogenic Regulator - Options 1171-5 and 2171-36
(Refer to Figure 2, Model 1171 or 2171):
1. Start with the block valves closed. A bypass
valve may be used to maintain inlet pressure
in upstream system without changing following
steps.
2. Relax the range spring by turning the adjusting
screw counter clockwise (CCW) a minimum of
three (3) full revolutions. This reduces the inlet
(upstream) pressure setpoint.
3. If it is a “hot” piping system, and equipped with
a bypass valve, slowly open the bypass valve
to pre-heat the system piping and to allow slow
expansion of the piping. Assure proper steam
trap operation if installed. Closely monitor inlet
(upstream) pressure via gauge to assure not
over-pressurizing. NOTE: If no bypass valve is
installed, extra caution should be used in starting
up a cold system; i.e. do everything slowly.
4. Crack open the inlet (upstream) block valve.
5. Slowly open the outlet (downstream) block valve
observing the inlet (upstream) pressure gauge.
Determine if the regulator is flowing. If not, slowly
rotate the regulator adjusting screw counter
clockwise (CCW) until flow begins.
6. Continue to slowly open the outlet (downstream)
block valve until fully open.
IV. START-UP 7. Observing the inlet (upstream) pressure gauge,
rotate the adjusting screw clockwise (CW) slowly
until the inlet pressure begins to rise. Rotate CW
until the desired setpoint is reached.
8. Continue to slowly open the inlet (upstream block
valve. If the inlet (upstream) pressure exceeds
the desired setpoint pressure, rotate the adjusting
screw CCW until the pressure decreases.
9. When flow is established steady enough that both
the outlet and inlet block valves are fully open,
begin to slowly close the bypass valve, if installed.
10. Develop system flow to a level near its expected
normal rate, and reset the regulator setpoint by
turning the adjusting screw CW to increase inlet
pressure, or CCW to reduce inlet pressure.
11. Using a downstream valve, reduce system flow
to a minimum level and observe setpoint. Inlet
pressure will rise from the setpoint of Step 9.
(Ensure this rise does not exceed the stated
upper limit of the range spring (16) by greater than
50%, i.e. 20-80 psig (1.4 - 5.5 Barg) range spring,
at maximum flow the inlet pressure should not
exceed 1.5 x 80 psig (5.5 Barg), or 120 psig (8.3
Barg). If it does, consult factory).
12. Increase flow to maximum level, if possible. Inlet
(upstream or P1) pressure should fall off. Readjust
setpoint as necessary at the normal flow rate.
SECTION III
1. Movement occurs as pressure variations register
on the diaphragm. The registering pressure is
the inlet, P1, or upstream pressure. The range
spring opposes diaphragm movement. As
inlet pressure drops, the range spring pushes
III. PRINCIPLE OF OPERATION the diaphragm down, closing the port; as inlet
pressure increases, the diaphragm pushes up
and the port opens.
2. A complete diaphragm failure will cause the
regulator to fail closed.
SECTION IV
a. Recommended installation is with spring
chamber hanging directly below the body in a
vertical downwards orientation. Allows water
to drain; etc.
b. Recommend inert purge gas to spring chamber
through vent hole and out drain hole.
11. Regulatorsarenottobedirectburiedunderground.
12. For insulated piping systems, recommendation is
to not insulate regulator.
13. Spring Chamber Vent Tap – Option -25: Pipe
spring chamber vent opening to remote location.
CAUTION
Installation of adequate overpressure protection is
recommended to protect the regulator from overpressure
and all downstream equipment from damage in the event
of regulator failure.

IOM-1171/2171 3
VI. MAINTENANCE
SECTION V
V. SHUTDOWN
1. On systems with a bypass valve, and where
system pressure is to be maintained as the
regulator is shut down, slowly open the bypass
valve while closing the inlet (upstream) block
valve. Fully close the inlet (upstream) block valve.
(When on bypass, the system pressure must be
constantly observed and manually regulated.
Close the outlet (downstream) block valve.
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 regulator removal is required.
SECTION VI
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
removal, handling, cleaning and disposal of
nonreuseable parts, i.e. gaskets, etc.
3. Refer to Figure 1, Model 1171 or 2171 for the
basic regulator and Figure 2, Model 1171 or
2171 for the cryogenic regulator. Blow-ups of
options and the composition seat trim are on
either drawing.
B. Diaphragm Replacement - Model 1171:
1. Install the body (1) in a vise with the spring
chamber (2) oriented upwards.
3. Loosen spring chamber (2) by placing wrench
on “flats” and rotating CCW making sure not
to use the flats on either side of the vent hole.
4. Remove spring chamber (2), range spring
(16), spring button (4).
5. Remove the diaphragm subassembly
consisting of the pressure plate nut (7), lock
washer (6), pressure plate (3), diaphragm
(10), piston O-ring (13) and piston (12).
NOTE: Refer to the quantity of diaphragms
(10) incorporated per the bill of materials.
Depending on inlet pressure level, multiple
metal diaphragms (10) may be “stacked”.
6. Loosen pressure plate nut (7) and separate
all parts (3, 6, 7, 10, 12 &13) of the diaphragm
subassembly.
Model's 1171/2171 Diaphragm Subassembly
7. Inspect pressure plate (3) to ensure no
deformation due to over-pressurization. If
deformed, replace.
8. Remove diaphragm gasket (11). (If a
composition diaphragm is used there is no
diaphragm gasket (11)).
9. Clean body (1) and diaphragm flange.
NOTE: On regulators originally supplied as
“oxygen clean”, Option s 1171-5 & -55, 2171-
36 & -55, maintenance must include a level
of cleanliness equal to Cashco's cleaning
standard #S-1134. Contact factory for details.
2. Relax range spring (16) by turning adjusting
screw (5) CCW until removed from spring
chamber (2).
13
10
67
3
12
WARNING
SYSTEM UNDER PRESSURE. Prior to performing any
maintenance, isolate the regulator from the system and
relieve all pressure. Failure to do so could result in
personal injury.
CAUTION
Do not walk away and leave a bypassed regulator
unattended.
CAUTION
To prevent damage to body, use lead jaws when placing
body in a vise. Position body so that vise closes over the
side inlet connections.
WARNING
SPRING UNDER COMPRESSION. Prior to removing
spring chamber, relieve spring compression by backing
out the adjusting screw. Failure to do so may result in
flying parts that could cause personal injury.

4 IOM-1171/2171
10. Reassemble diaphragm subassembly by
placing piston O-ring (13), diaphragm(s)
(10), pressure plate (3) and lock washer (6)
over threaded post of piston(12). Assure the
pressure plate (3) is placed with curved outer
rim down next to the diaphragm (10) surface.
Place a thread sealant compound similar to
Loctite #271 on the threads of the piston's
post (12) prior to tightening the pressure plate
nut (7) to the following torque values:
Sizes Diaphragm Torque
ALL Metal 60 In-lbs (6.8 N-m)
Composition 15 In-lbs (1.7 N-m)
11. Formetaldiaphragm(s)(10),placediaphragm
gasket (11) into body (1) recess (none
required for composition diaphragm). Set
diaphragm subassembly into the body.
12. Place the range spring (16) over the pressure
plate nut (7) of the diaphragm subassembly.
13. Place multipurpose, high temperature
grease into depression of spring button (4)
where adjusting screw bears. Set spring
button (4) onto range spring (16); assure
spring button is laying flat on spring.
14. Rotate the spring chamber (2) CW by hand
into the threaded portion of the body (1)
assuring not to cross thread. NOTES: Inspect
and clean threads prior to reassembly. For
the Model 2171 apply an appropriate thread
lubricant to the spring chamber (2) threads
prior to reassembly to prevent seizing
together with body (1). Continue hand
rotating CW until firmly seated against the
upper diaphragm gasket (11). Tighten the
spring chamber (2) and body (1) connection
to the following torque value: All sizes - 30-35
Ft. lbs (41-47 Nm).
15. Reinstall adjusting screw (5) with locknut (8)
into the spring chamber (2).
16. Pressurize body with air and spray liquid leak
detector around body (1) and spring chamber
(2) to test for leakage. Ensure that an inlet
pressure is maintained during this leak test
of at least mid-range spring level; i.e. 20-80
psig (1.4-5.5 Barg) range spring, 50 psig (3.4
Barg) test pressure minimum.
C. Diaphragm Replacement - Model 2171:
1. Procedures are the same as Model 1171.
2. For SST body (1) and SST spring chamber
(2), use thread lubricant to minimize potential
of seizing threads.
D. Special Instructions for Diaphragm Removal:
1. If the TFE coated diaphragm is utilized on the
Model 2171, the TFE coating is the wetted
side of the diaphragm.
2. If the Option -2 handwheel is utilized, the
adjusting screw (5) and locknut (8) are re-
placed with a handwheel (17) and lock nut
(8). With the Option-22 panel mounting w/
handwheel, the adjusting screw and lock nut
are replaced with a handwheel (17), lock nut
(8) and a panel mounting nut (18).
3. Use only those gaskets manufactured and
supplied by Cashco, Inc.
E. Piston / Seat Replacement:
1. Trim removal requires that diaphragm
subassembly be removed and disassembled.
Refer to previous procedure, Section VI.B.
2. Inspect inside surface of cylinder wall inside
the body. (NOTE: The cylinder is an integral
part of the body. Replace the regulator should
any damage be noted on the cylinder or seat
surfaces). If there are no signs of erosion/
wear on seating surfaces, piston (12) alone
may be replaced.
If composition seat (14) is damaged or worn,
rotate the set screws (15) CCW to remove.
Grasp the seat and pull it out of the piston(12).
Insert new seat into the end of the piston and
install set screws to hold the seat in place.
3. Clean body (1) cavity. Clean all parts to be
reused. NOTE: On regulators originally
supplied as “oxygen clean”, Option's 1171-
5-55, 2171-36-55, maintenance must include
a level of cleanliness equal to Cashco's
cleaning standard #S-1134. Contact factory
for details.
4. Use special care cleaning the body (1) and
cylinder shoulder, as this pressurized joint is
metal-to-metal with no gasket.
5. Reinstall diaphragm subassembly per
Section VI.B., Diaphragm Replacement.
6. Bench test unit for suitable operation. NOTE:
Regulators are not tight shut off devices.
Even if pressure falls below setpoint, a
regulator may or may not develop bubble
tight shut off. In general, tighter shut off can
be expected with composition seat.
7. Spray liquid leak detector to test for leakage
around body (1) and spring chamber (2). Test
pressure should be the maximum allowed by
the range spring (16) at the inlet.

IOM-1171/2171 5
SECTION VII
2. Regulator inlet (upstream) too high:
VII. TROUBLE SHOOTING GUIDE
1. Erratic operation; chattering.
3. Leakage through the spring chamber vent hole.
4. Sluggish operation.
Possible Causes Remedies
A. Oversized regulator. A1. Check actual flow conditions, re-size regulator for minimum and
maximum flow.
A2. Increase flow rate.
A3. Decrease regulator pressure drop; decrease inlet pressure by
placing a throttling orifice in inlet piping union.
A4. Install next step higher range spring. Contact factory
A5. Before replacing regulator, contact factory.
B. Worn piston; inadequate guiding. B. Replace regulator.
Possible Causes Remedies
A. Regulator undersized. A1. Confirm by opening bypass valve together with regulator.
A2. Check actual flow conditions, re-size regulator; if regulator has
inadequate capacity, replace with larger unit.
B. Incorrect range spring (screwing in CW of adjusting
screw does not allow bringing pressure level up to
proper level.
B. Replace range spring with proper lower range.
B.2 Contact factory.
C. Too much rise (build). C1. Review rise (build) expected.
C2. Contact factory.
Possible Causes Remedies
A. Normal-life diaphragm failure. A1. Replace diaphragm.
B. Abnormal short-life diaphragm failure. B1. Can be caused by excessive chattering. See No. 1. to
remedy chatter.
B2. Can be caused by corrosive action. Consider alternate diaphragm
material.
B3. For composition diaphragms, ensure not subjecting to over
temperature conditions.
B4. Upstream (inlet) pressure build-up occurring that overstresses
diaphragms. Relocate regulator or protect with safety relief
valve.
Possible Causes Remedies
A. Plugged spring chamber vent. A. Clean vent opening.
B. Fluid too viscous. B. Heat fluid. Contact factory.

6 IOM-1171/2171
SECTION VIII
NEW REPLACEMENT UNIT:
Contact your local Cashco, Inc., Sales
Representative with the Serial Number and Product
code. With this information they can provide a
quotation for a new unit including a complete
description, price and availability.
–7–
VIII. ORDERING INFORMATION
NEW REPLACEMENT UNIT vs PARTS "KIT" FOR FIELD REPAIR
To obtain a quotation or place an order, please retrieve the Serial Number and Product Code that was stamped
on the metal name plate and attached to the unit. This information can also be found on the Bill of Material
("BOM"), a parts list that was provided when unit was originally shipped. (Serial Number typically 6 digits).
Product Code typical format as follows: (last digit is alpha character that reflects revision level for the product).
PARTS "KIT" for FIELD REPAIR:
Contact your local Cashco, Inc., Sales
Representative with the Serial Number and Product
code. Identify the part s and the quantity required
to repair the unit from the "BOM" sheet that was
provided when unit was originally shipped.
NOTE: Those part numbers that have a quantity indicated
under "Spare Parts" in column "A” reflect minimum
parts required for inspection and rebuild, - "Soft
Goods Kit". Those in column “B” include minimum
trim replacement parts needed plus those "Soft
Goods" parts from column "A".
If the "BOM" is not available, refer to the cross-
sectional drawings included in this manual for part
identification and selection.
A Local Sales Representative will provide quotation
for appropriate Kit Number, Price and Availability.
CAUTION
Do not attempt to alter the original construction of any
unit without assistance and approval from the factory.
All purposed changes will require a new name plate
with appropriate ratings and new product code to
accommodate the recommended part(s) changes.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be
construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right
to modify or improve the designs or specifications of such product at any time without notice.
Cashco, Inc. does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any
Cashco, Inc. product remains solely with the purchaser.

IOM-1171/2171 7
MODEL 1171
Figure 2: Option -5 Cryogenic, Model 1171,
Metal Seat Design
Option –20, Dome Loaded
Option –22 Panel Mounting (handwheel
portion is same for Option -2 Handwheel)
Spring Chamber Thread 3/4"-16 UNF-2A
Figure 1: Basic Model 1171 with
Metal Seat Design
IRepair
Item No. Description Kit B
1 Body
2 Spring Chamber
3 Pressure Plate
4 Spring Button
5 Adjusting Screw or
Handwheel Assy
6 Lock Washer
7 Pressure Plate Nut
8 Adjusting Screw Lock Nut
9 Nameplate (Not Shown)
10 Diaphragm(s) ††
11 Diaphragm Gasket ††
12 Piston ††
13 Piston O-ring ††
14 Composition Seat ††
15 Seat Set Screws ††
16 Range Spring
17 Handwheel
18 Mounting Nut
Composition Seat Design
(NOTE: Mount in Horizontal line with
Adjusting Screw down as shown.)
3
2
7
vent
1/8" (DN6) Drain Hole

MODEL 2171
Repair
Item No. Description Kit B
1 Body
2 Spring Chamber
3 Pressure Plate
4 Spring Button
5 Adjusting Screw
or Handwheel Assy
6 Lock Washer
7 Pressure Plate Nut
8 Adjusting Screw Lock Nut
9 Nameplate (Not Shown)
10 Diaphragm(s) ††
11 Diaphragm Gasket ††
12 Piston ††
13 Piston O-ring ††
14 Composition Seat ††
15 Seat Set Screws ††
16 Range Spring
17 Handwheel
18 Mounting Nut
20 Thrust Bearing
21 Upper Bearing Washer
22 Lower Bearing Washer
(NOTE: Mount in Horizontal line with
Adjusting Screw down as shown.)
Figure 2: Option -36 Cryogenic, Model 2171,
Metal Seat Design
Figure 1: Basic Model 2171 with
Metal Seat Design
Option -20, Dome Loaded
Option -80, High Pressure
Spring Chamber Construction
Composition Seat Design
Option -22 Panel Mounting (Handwheel
portion is same for Option -2 Handwheel)
Spring Chamber Thread 3/4"-16 UNF-2A
2
37
vent
1/8" (DN6) Drain Hole
Cashco, Inc.
P.O. Box 6
Ellsworth, KS 67439-0006
PH [phone]
Fax. # [phone]
www.cashco.com
email: [email protected]
Printed in U.S.A. IOM-1171/2171
Cashco do Brasil, Ltda.
Al.Venus, 340
Indaiatuba - Sao Paulo, Brazil
PH [phone]
Fax. No.
www.cashco.com
email: [email protected]
Cashco GmbH
Handwerkerstrasse 15
15366 Hoppegarten, Germany
PH [phone]
Fax. No. [phone]
www.cashco.com
email: [email protected]