Armstrong GP-2000CS is a high-performance, externally piloted reducing valve for large capacity requirements. Typical use is on intermittent service, including applications such as heat exchangers, steam coils, rotating dryers, process equipment, and heating systems. With a 20:1 rangeability and high Cv, the GP-2000CS is reliable and accurate (+/-1% of pressure set point from 5% to 100% of flow) over a long, trouble-free service life. Stellited stainless steel working parts are renewable in-line. It is single-seated for dead-end service.

Specifications

Application	Inlet Pressure psig (bar)	Reduced Pressure psig (bar)	Spring Color	Maximum Temperature	Minimum Differential psig (bar)
Steam (NPT)	15 - 450 (1 - 31)	3 - 21 (.21 - 1.4)	Yellow	600°F (315°C)	7 (.48)
Steam (150 lb Flanged)	15 - 140 (1 - 9.6)	15 - 200 (1 - 13.6)	Green	600°F (315°C)	7 (.48)
Steam (300 lb Flanged)	15 - 450 (1 - 31)	190 - 300 (13.1 - 20.6)	Brown	600°F (315°C)	7 (.48)

Materials:

• Body: Carbon Steel WCB ASTM216 A216M-08 (Silver color)
• Main Valve/Seat: Stainless Steel 304 / Stainless Steel Stellite
• Pilot Valve/Seat: 420 Stainless Steel
• Diaphragm: Stainless Steel AISI 301

Dimensions and Weights

Size	L (NPT)	L (150#)	L (300#)	A	F	H Integral	H1	H2	Weight (NPT)	Weight (150#)	Weight (300#)	Cv
1/2" (15mm)	5-15/16"	-	-	7-15/16"	6-7/8"	15-3/4"	6-3/4"	9-5/8"	35 lb	-	-	5.0
3/4" (20mm)	5-15/16"	-	-	7-15/16"	6-7/8"	15-3/4"	6-3/4"	9-5/8"	35 lb	-	-	7.2
1" (25mm)	6-5/16"	-	-	8-15/16"	7-1/16"	15-15/16"	6-15/16"	10"	49 lb	-	-	10.9
1-1/4" (32mm)	7-1/8"	-	-	8-15/16"	7-7/16"	17-1/8"	7-5/8"	11-1/8"	53 lb	-	-	14.3
1-1/2" (40mm)	7-1/8"	-	-	8-15/16"	7-7/16"	17-1/8"	7-5/8"	11-1/8"	53 lb	-	-	18.8
2" (50mm)	9-1/8"	8-9/16"	9-1/8"	10-15/16"	7-11/16"	19-5/8"	8-1/2"	12-5/8"	62 lb	88 lb	92 lb	32
2-1/2" (65mm)	-	10-15/16"	11-1/2"	13-13/16"	8-5/16"	21-3/4"	9-13/16"	14-3/4"	-	159 lb	168 lb	60
3" (80mm)	-	11-3/4"	12-7/16"	13-13/16"	8-3/4"	22-5/8"	10-7/16"	15-3/4"	-	174 lb	185 lb	78
4" (100mm)	-	13-1/2"	14-1/8"	15-13/16"	9-7/16"	25-15/16"	12-5/8"	19-1/4"	-	276 lb	293 lb	120

Installation Instructions

1. An Armstrong Inverted Bucket Steam Trap is recommended to drain the condensate at the inlet of the PRV.
2. An Armstrong Y-Strainer should be installed before the PRV to reduce the chance of dirt fouling.
3. Pressure gauges should be installed before and after the PRV. The downstream gauge should be installed in or near the control pipe (5/16" O.D.).
4. Control pipe connections go into 1/4" tapping on the side of the pilot valve. Be certain the pipe is pitched away from the PRV to drain condensate away from the pilot. Erratic control could result if this is not done. Control pipe length should be a minimum of 10 outlet pipe diameters from the last tee, elbow, or fitting.
5. If a bypass line is needed to allow system operation while the valve is being serviced, install a quality globe valve on the bypass line. Leaking valves will cause system problems.
6. Piping immediately downstream of PRV should be expanded to accommodate low-pressure expansion through a PRV. Approximately 10,000 – 12,000 FPM maximum velocity.
7. Install the PRV with diaphragm chamber down and with flow in the direction of the arrow on the body.
8. Do not install a quick opening or quick closing valve on the downstream side of the PRV. This can cause erratic pressure control and cause safety relief valves to discharge.

WARNING

Improper sizing or adjustment of the pressure reducing valve may cause hunting, scale problems, water hammer, etc., and can heavily damage the main parts of the valve.

Adjustment Procedure:

1. Close the gate valves before and after the pressure reducing valve and blow fluid leisurely through the by-pass line. Adjust the opening of the by-pass globe valve so as not to blow the safety relief valve. After draining, be sure to close the by-pass globe valve.
2. Loosen the lock nut and adjusting screw to relieve the pressure 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 the desired pressure is obtained while watching the pressure gauge at the outlet side.
5. Slowly open the outlet side valve to the full open position.
6. After adjustment, tighten the lock nut.

INFO

Downstream usage must be present in order to set any pressure-reducing valve.

Disassembly and Assembly

DANGER

Before disassembly, check to make sure that the valves before and after the reducing valve are closed, including the valve in the control pipe. Also, make sure that the pressure has been relieved and that the valves are holding.

Disassembly of the Pilot Valve

1. Loosen the lock nut, turn the adjusting screw counterclockwise and turn until pressure is relieved from the spring.
2. Remove the hex head bolts and take out the top spring plate, adjusting spring, bottom plate, and two pilot diaphragms.
3. Remove the pilot valve capsule (hexagonal part at the center of the pilot body). Disassemble pilot valve capsule – place a 7/32” socket over small hexagonal screw in middle of capsule and hold opposite end with a flat-head screwdriver. Turn counterclockwise to unscrew and expose valve stem and seat.

Disassembly of the Main Valve

1. Disconnect the copper tubing on the side of the valve.
2. Remove the four hex head bolts from the pilot body to remove the pilot from the main body. If the pilot is mounted remotely, remove the bolts to the main valve top cover. Care should be taken when doing this – the main valve is held by a spring, which is compressed. Once bodies are apart, remove spring retainer, screen, main spring, and main valve.
3. If the seat must be replaced, remove the four nuts that attach the main body to the top diaphragm case. The main valve seat is tightened from the bottom side of the body using a “T” bar. Loosen with “T” bar and unscrew main valve seat from the top.

Disassembly of the Main Diaphragm

1. Remove all bolts holding the bottom diaphragm cases together.
2. Separate both halves. Remove both main diaphragms, retainer, and main spindle.

Assembly

1. Check to make sure there are no scratches on the main valve, valve seat, or pilot valve. If there are no scratches apply lapping compound and re-lap the valve and seat.
2. Make sure the sliding parts (Pilot valve stem and main valve stem) move freely.
3. Never-Seeze® gasket compound should be used on both main diaphragms and on the bottom of pilot diaphragms.
4. Assemble valve in reverse order from disassembly.
5. Tighten bolts uniformly (crisscross pattern).
6. Verify if your valve has old or new type tubing to assure proper placement of orifices.
7. Be sure fittings and tee fitting are in the correct position and not over tightened.
8. Make sure copper pilot valve gasket and main valve seat gasket are in place before tightening pilot valve capsule and main valve seat.

Troubleshooting

Problem	Cause	Solution
Outlet Pressure does not reach desired value.	Inlet pressure is not adequate.	Raise inlet pressure if possible.
	Adjustment is not proper.	Dismantle and clean.
	Orifice is too large or plugged.	Install proper fitting or clean/replace.
	Pilot valve is clogged.	Disassemble and clean pilot valve seat. Check screen.
	Main diaphragms are damaged.	Disassemble and replace main diaphragms.
	Valve size is too small.	Resize and install larger valve.
Secondary pressure exceeds the pressure setting.	Adjustment is not proper.	Readjust.
	Orifice of fitting is plugged.	Clean or replace fitting.
	Dirt caught between main/pilot valve and seat.	Flush out dirt or lap the valve and seat.
	Dirt between main spindle and guide.	Clean.
	By-pass valve is not shut or is leaking.	Repair or replace.
	Sensing line is plugged or not connected.	Clean, replace, or install sensing line properly.
Operation is unstable.	Orifice fitting is partially plugged.	Remove and clean or replace.
	Sensing pipe installed with too much turbulence.	Install sensing pipe at another location.
	Liquid is collecting in sensing line.	Slant pipe away from PRV.
	Quick opening/closing valve too close.	Relocate PRV.
Excessive noise is present.	Valve size is larger than required (chatter).	Change valve or add orifice plate to outlet.
	Pressure reduction ratio exceeds 20:1.	Use two stage reduction.
	Fluid velocity is too high.	Resize station using two stage reduction or use sound silencer.
	Automatic valve is too close to PRV.	Relocate.