Armstrong GP-1 Installation and operating instructions

Typical Piping For Gas
Bulletin No. AY-758-B
Typical Piping For Steam
This bulletin should be used by experienced personnel as a guide to the installation of the Models
GP-1, GP-18, GP-28 and GP-1000 Pressure Reducing Valve. Selection or installation of equipment should
always be accompanied by competent technical assistance. You are encouraged to contact Armstrong Interna-
tional, Inc. or its local sales representative for additional information.
Start-Up and Adjusting Procedures
Improper adjustment of the pressure reducing valve
may cause hunting, improper control and possible
damage to the valve itself. Adjust the valve as follows:
1. Close the gate valves before and after the pressure reduc-
ing valve and blow fluid leisurely through the bypass line,
adjusting the opening of the bypass globe valve so as not to
blow the safety relief valve if installed. After draining, be
sure to close the bypass globe valve.
2. Loosen the lock nut and adjusting screw to relieve the
tension on the adjusting spring.
3. Slowly open the inlet side gate valve to the full open
position, and open the outlet side gate valve enough so that
a little fluid can flow through.
4. Slowly turn the adjusting screw clockwise until desired
pressure is obtained while watching the pressure gauge at
the outlet side.
5. Slowly open the outlet side valve to the full open
6. Adjust pressure again after system stabilizes and when there
is a load on the system. Turning the adjusting screw: -
Clockwise increases pressure, counter-clockwise decreases
pressure.
7. After adjustment, tighten the lock nut and replace the cap.
DISASSEMBLY PROCEDURE FOR GP-1, GP-18, GP-28
and GP-1000 (Refer to diagram on page 2)
Prior to disassembly, make sure that gate valves
before and after the PRV are closed, and that there is no
residual pressure in the PRV.
Disassembly of the Pilot Valve
1. Remove the cap (5), slightly loosen the lock nut (18), and
turn the adjusting screw (17) counterclockwise to unload
the adjusting spring (21).
2. Remove the hexagon bolts (23) from the spring housing (4),
remove the spring housing, and take out parts 14, 15, 16
and the diaphragm (13). Take out the diaphragm by using a
MODEL GP-1, 18, 28 and 1000
INSTALLATION & MAINTENANCE INSTRUCTIONS
position.

66
66
6
Troubleshooting Guide and Disassembly Instructions
Troubleshooting Guide
CapCap
CapCap
Cap
Lock nutLock nut
Lock nutLock nut
Lock nut
Top PlateTop Plate
Top PlateTop Plate
Top Plate
2121
2121
21
Bottom PlateBottom Plate
Bottom PlateBottom Plate
Bottom Plate
1515
1515
15
1414
1414
14 Spring RetainerSpring Retainer
Spring RetainerSpring Retainer
Spring Retainer
1313
1313
13
2828
2828
28
2323
2323
23
BoltBolt
BoltBolt
Bolt
tool with a sharp edge applied to the notch of the
diaphragm.
3. Take out the pilot valve seat (11) by removing the
pilot valve seat from the center of the top cover (3) by
using a ring spanner or socket wrench. Then pick out
the pilot valve (10) and the spring (20).
Piston Disassembly
1. Remove the hexagon bolts (23) from the top cover (3),
and the top cover from the body, and pull out the
piston (8) and the cylinder (9).
Main Valve Disassembly
1. Remove the hexagon bolts (23) from the bottom cover
(2), and the bottom cover from the body, and take out
the spring (19) and the main valve (6).
Notes to Re-assemble
1. Make sure that the main valve, the valve seat, the pilot
valve and the pilot valve seat have no flaws. Even a
small flaw on the seats may cause leakage.
2. Make sure that sliding movement is smooth.
3. Be sure to replace all gaskets and diaphragms with
new ones. (If cutting a new gasket (28) or (26) make
sure it is the same thickness as the old gasket).
55
55
5
Adjusting ScrewAdjusting Screw
Adjusting ScrewAdjusting Screw
Adjusting Screw
1717
1717
17
1818
1818
18
44
44
4
Spring HousingSpring Housing
Spring HousingSpring Housing
Spring Housing
16
Adjusting SpringAdjusting Spring
Adjusting SpringAdjusting Spring
Adjusting Spring
DiaphragmDiaphragm
DiaphragmDiaphragm
Diaphragm
GasketGasket
GasketGasket
Gasket
1111
1111
11 Pilot Valve SeatPilot Valve Seat
Pilot Valve SeatPilot Valve Seat
Pilot Valve Seat
3333
3333
33 Pilot Valve RingPilot Valve Ring
Pilot Valve RingPilot Valve Ring
Pilot Valve Ring
1010
1010
10 Pilot ValvePilot Valve
Pilot ValvePilot Valve
Pilot Valve
2020
2020
20 SpringSpring
SpringSpring
Spring
33
33
3
Top CoverTop Cover
Top CoverTop Cover
Top Cover
1212
1212
12
StrainerStrainer
StrainerStrainer
Strainer
GasketGasket
GasketGasket
Gasket2929
2929
29
2525
2525
25
3232
3232
32
3434
3434
34
GuideGuide
GuideGuide
Guide
PipePipe
PipePipe
Pipe
GasketGasket
GasketGasket
Gasket
CapCap
CapCap
Cap
PistonPiston
PistonPiston
Piston
RIngRIng
RIngRIng
RIng
88
88
8
PistonPiston
PistonPiston
Piston
99
99
9
CylinderCylinder
CylinderCylinder
Cylinder
BodyBody
BodyBody
Body 11
11
1
77
77
7
MainMain
MainMain
Main
ValveValve
ValveValve
Valve
SeatSeat
SeatSeat
Seat
Main ValveMain Valve
Main ValveMain Valve
Main Valve
1919
1919
19
SpringSpring
SpringSpring
Spring
GasketGasket
GasketGasket
Gasket 2626
2626
26
22
22
2
2222
2222
22
PlugPlug
PlugPlug
Plug
BottomBottom
BottomBottom
Bottom
CoverCover
CoverCover
Cover
11
11
1
BoltBolt
BoltBolt
Bolt
2525
2525
25 Guide PipeGuide Pipe
Guide PipeGuide Pipe
Guide Pipe
GasketGasket
GasketGasket
Gasket
3131
3131
31 Pilot Valve CapPilot Valve Cap
Pilot Valve CapPilot Valve Cap
Pilot Valve Cap
GasketGasket
GasketGasket
Gasket
2727
2727
27
BoltBolt
BoltBolt
Bolt
2323
2323
23
Problem Causes Solutions
The desired
pressure
cannot be
obtained
The inlet pressure is too
low or too high.
Change the pressure to the
appropriate level.
The strainer in the top
cover is clogged by
foreign matter.
Disassemble and clean the
strainer.
The piston-cylinder,
clearance is clogged by
foreign matter
Disassemble and clean the
piston and the cylinder. If
a flaw is found, finish the
surface by using a file or
sand paper.
The valve size is smaller
than what is required.
Change the size to the
appropriate one.
The adjustment is not
appropriate.
Readjust according to the
adjusting procedure (page
1).
The inlet strainer is
clogged by foreign
matter.
Disassemble and clean the
strainer.
The pressure gauge is
out of order. Replace the gauge.
The outlet
pressure
rises higher
than the
specified
pressure.
The main valve or the
valve seat is
contaminated by foreign
matter.
Disassemble and clean the
valve and seat.
The pilot valve or the
pilot valve seat is
contaminated by foreign
matter.
Disassemble and clean the
pilot valve and seat.
The piston-cylinder
clearance is clogged by
foreign matter.
Disassemble and clean the
valve or the seat.
The bypass valve is
leaking.
Repair or replace the
bypass valve.
Abnormal
noise is
heard.
The valve size is larger
than what is required.
Install the correct size
valve.
The reducing ratio is
greater than 10:1.
Reduce pressure by
staging with second PRV.
Water hammer. Install a drip trap at the
reducing valve inlet.
There is a
quick-responding valve
near the PRV.
Provide as long a distance
as possible between the
two valves.
Others
All springs or
diaphragms are
damaged.
Replace all damaged
springs or diaphragms.
Armstrong-Yoshitake, Inc., 221 Armstrong Blvd., P.O. Box 408, Three Rivers, Michigan 49093 - USA Ph: [phone] Fax: [phone]
www.armstrong-intl.com
Bulletin No. AY-758-B 9/99 Printed in U.S.A.