PN25
Armstrong GP-1000 Series valves are pilot-controlled for accurate regulation of pressure under wide-ranging flow. The internal pilot design eliminates the need for external components and piping. Internally piloted GP Series valves are capable of larger capacity and greater accuracy than direct-acting valves, providing a 20:1 turndown ratio and +/-5% set point accuracy.
Completely supported by piping, the lightweight GP Series valves install easily with NPT or flanged connections. A stainless steel diaphragm, hardened stainless steel working parts, and an integral removable strainer team up to provide high performance over a long, trouble-free service life. Valves are equipped with a single-seated main valve, piston valve rings for longer life, and an external adjusting screw with a locking nut. All working parts are renewable in-line, and the valves provide ANSI Class IV Shutoff. For air service, a Teflon® valve seat ensures a tight seal.
Specifications and Materials
| Model Number | Inlet Pressure | Reduced Pressure | Spring Color | Application | Max Temp | Min Diff. | Body Material | Main Valve / Seat | Pilot Valve / Seat | Piston / Cylinder | Diaphragm |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NPT GP-1000 | 15 - 250 psig (1 - 17 barg) | 7 - 125 psig (.48 - 8.6 barg) | Black | Steam | 450°F (232°C) | 7 psig (.48 barg) | Ductile Iron ASTM A536 | SS AISI 420 | SS AISI 403/420 | SS AISI 420 / SS AISI 403 | SS AISI 301 |
| NPT GP-1000 | 15 - 250 psig (1 - 17 barg) | 125 - 200 psig (8.6 - 13.8 barg) | Green | Steam | 450°F (232°C) | 7 psig (.48 barg) | Ductile Iron ASTM A536 | SS AISI 420 | SS AISI 403/420 | SS AISI 420 / SS AISI 403 | SS AISI 301 |
| 150 ANSI GP-1000 | 15 - 150 psig (1 - 10 barg) | 7 - 125 psig (.48 - 8.6 barg) | Black | Steam | 450°F (232°C) | 7 psig (.48 barg) | Ductile Iron ASTM A536 | SS AISI 420 | SS AISI 403/420 | Bronze / Bronze ASTM C36000 | SS AISI 301 |
| NPT GP-1000A | 15 - 150 psig (1 - 10 barg) | 7 - 125 psig (.48 - 8.6 barg) | Black | Air & Gas | 175°F (80°C) | 7 psig (.48 barg) | Ductile Iron ASTM A536 | SS AISI 420 / Brass w/NBR | SS AISI 403/420 | Bronze / Bronze ASTM C36000 | SS AISI 301 |
| 150 ANSI GP-1000A | 15 - 150 psig (1 - 10 barg) | 7 - 125 psig (.48 - 8.6 barg) | Black | Air & Gas | 175°F (80°C) | 7 psig (.48 barg) | Ductile Iron ASTM A536 | SS AISI 420 / Brass w/NBR | SS AISI 403/420 | Bronze / Bronze ASTM C36000 | SS AISI 301 |
| GP-1000SS / GP-1000AS | 15 - 150 psig (1 - 10 barg) | 7 - 125 psig (.48 - 8.6 barg) | Black | Steam | 450°F (232°C) | 7 psig (.48 barg) | SS AISI 304 | SS AISI 420 | SS AISI 403/420 | SS AISI 420 / SS AISI 403 | SS AISI 301 |
Notes: Sizes 2" (50 mm) and below are NPT connections. Sizes 2" (50 mm) and larger are flanged connections. GP-1000SS/GP-1000AS are available in 1/2" - 2" only and are flanged with NPT companion flanges.
Dimensions and Weights
| Size (in) | Size (mm) | L (in) | L (mm) | H (in) | H (mm) | H1 (in) | H1 (mm) | Weight lb (kg) | Cv Factor |
|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 15 | 5-7/8 | 150 | 11-1/4 | 285 | 2-1/2 | 64 | 15-1/2 (7) | 1 |
| 3/4 | 20 | 6-1/8 | 155 | 11-1/4 | 285 | 2-1/2 | 64 | 15-1/2 (7) | 2.3 |
| 1 | 25 | 6-5/16 | 160 | 11-7/8 | 300 | 2-5/8 | 67 | 19 (8.5) | 4 |
| 1-1/4 | 32 | 7-1/2 | 190 | 12-3/4 | 323 | 3-1/4 | 82 | 25-1/2 (12) | 6.5 |
| 1-1/2 | 40 | 7-1/2 | 190 | 12-3/4 | 323 | 3-1/4 | 82 | 27-1/2 (12.5) | 9 |
| 2* | 50 | 8-11/16 | 220 | 13-5/8 | 347 | 3-11/16 | 93 | 40 (18) | 16 |
| 2-1/2 | 65 | 9-5/8 | 245 | 14 | 357 | 4 | 100 | 66 (30) | 25 |
| 3 | 80 | 11-3/8 | 290 | 15-7/8 | 404 | 4-13/16 | 122 | 77 (35) | 36 |
| 4 | 100 | 13 | 330 | 17-3/4 | 450 | 5-9/16 | 144 | 116 (53) | 64 |
Notes: GP-1000 is 1/2"-2" (20-50 mm) NPT, 2"- 4" (50-100 mm) ANSI 150 lb flanged. "L" Dimension for 2” 150# flange is 8-11/16” (220 mm).
Capacities
GP-1000 Capacities—Steam (kg/hr)
| Inlet (bar) | Outlet (bar) | 15mm | 20mm | 25mm | 32mm | 40mm | 50mm | 65mm | 80mm | 100mm |
|---|---|---|---|---|---|---|---|---|---|---|
| 1.03 | 0.55 | 18 | 42 | 73 | 119 | 164 | 292 | 456 | 657 | 1,168 |
| 0.34 | 21 | 49 | 85 | 138 | 191 | 339 | 529 | 762 | 1,355 | |
| 2.07 | 1.59 | 23 | 53 | 92 | 149 | 206 | 366 | 572 | 824 | 1,464 |
| .34 - .48 | 35 | 80 | 139 | 225 | 312 | 555 | 867 | 1,248 | 2,219 | |
| 3.45 | 2.90 | 30 | 68 | 119 | 193 | 267 | 475 | 742 | 1,069 | 1,900 |
| 2.07 | 45 | 102 | 178 | 290 | 401 | 713 | 1,114 | 1,604 | 2,852 | |
| .34 - 1.17 | 50 | 115 | 201 | 326 | 452 | 803 | 1,255 | 1,807 | 3,212 | |
| 6.89 | 5.86 | 54 | 124 | 216 | 351 | 486 | 864 | 1,350 | 1,945 | 3,457 |
| 4.83 | 74 | 169 | 295 | 479 | 663 | 1,179 | 1,842 | 2,652 | 4,715 | |
| .34 - 2.9 | 89 | 205 | 356 | 578 | 801 | 1,423 | 2,224 | 3,203 | 5,694 | |
| 10.00 | 8.62 | 83 | 191 | 332 | 540 | 748 | 1,330 | 2,077 | 2,991 | 5,318 |
| 6.89 | 113 | 259 | 450 | 732 | 1,013 | 1,801 | 2,815 | 4,053 | 7,206 | |
| 5.52 | 128 | 295 | 513 | 834 | 1,155 | 2,054 | 3,209 | 4,621 | 8,215 | |
| .55 - 4.6 | 128 | 294 | 511 | 830 | 1,150 | 2,044 | 3,194 | 4,599 | 8,176 | |
| 13.79 | 11.72 | 104 | 240 | 417 | 678 | 938 | 1,668 | — | — | — |
| 10.34 | 131 | 302 | 525 | 853 | 1,181 | 2,099 | — | — | — | |
| 8.62 | 155 | 357 | 621 | 1,009 | 1,398 | 2,485 | — | — | — | |
| .68 - 6.3 | 167 | 383 | 666 | 1,082 | 1,499 | 2,665 | — | — | — | |
| 17.24 | 13.79 | 147 | 339 | 590 | 959 | 1,327 | 2,360 | — | — | — |
| 12.07 | 176 | 404 | 703 | 1,143 | 1,583 | 2,814 | — | — | — | |
| 10.34 | 197 | 454 | 790 | 1,283 | 1,776 | 3,158 | — | — | — | |
| .89 - 8.06 | 205 | 472 | 821 | 1,335 | 1,848 | 3,285 | — | — | — |
Note: For air capacities m3/hr, multiply steam capacities kg/hr by 1.35. For air capacities scfm, multiply steam capacities lb/hr by 0.36.
Installation and Maintenance
Installation Hints
- An Armstrong inverted bucket steam trap (or Liquid Drainer Trap for air/gas) is recommended to drain condensate/liquid at the inlet of the pressure reducing valve (PRV).
- An Armstrong Y strainer (20-100 mesh, depending on fluid quality) with a blowdown valve should be installed before the PRV to reduce the chance of dirt fouling.
- Pressure gauges should be installed before and after the PRV.
- Piping a by-pass line with a globe valve around the PRV will allow system operation while the PRV is being serviced. It is also recommended to flush out the system prior to start-up.
- Do not install quick opening or closing valves downstream of the PRV.
- Install the PRV with the flow in the direction of the arrow on the body.
- Piping immediately downstream of the PRV should be expanded to account for low-pressure expansion of steam.
Startup and Adjustment 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:
- Close the gate valves before and after the pressure reducing valve and blowdown the strainer. If a strainer blowdown valve is not available, blowdown can be done through the bypass line, adjusting the opening of the bypass globe valve so as not to blow the safety relief valve. After draining, be sure to close the bypass globe valve.
- Loosen the lock nut and adjusting screw to relieve the tension on the adjusting spring.
- Adjustment must be made while steam/gas is being consumed at least 1/2 to 3/4 of maximum flow for best results.
- 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.
- Slowly turn the adjusting screw clockwise until the desired pressure is obtained while watching the pressure gauge at the outlet side.
- Slowly open the outlet side valve to the full open position.
- After adjustment, tighten the lock nut to secure the adjusting screw.
Troubleshooting Guide
| 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 pilot body is clogged. | Disassemble and clean the strainer. | |
| The piston-cylinder clearance is clogged. | Disassemble and clean the piston and cylinder. Refinish surface if flawed. | |
| The valve size is smaller than required. | Change to the appropriate valve size. | |
| The adjustment is not appropriate. | Readjust according to the adjustment procedure. | |
| The inlet strainer is clogged. | Disassemble and clean the strainer. | |
| The pressure gauge is not functioning. | Replace the gauge. | |
| The outlet pressure rises higher than specified. | The main valve or seat is contaminated. | Disassemble and clean the valve or seat. |
| The pilot valve or seat is contaminated. | Disassemble and clean the valve or seat. | |
| The piston-cylinder clearance is clogged. | Disassemble and clean the piston and cylinder. | |
| The bypass valve is leaking. | Repair or replace the bypass valve. | |
| Abnormal noise is heard. | The valve size is larger than required. | Install the correct size valve. |
| The reducing ratio is greater than 20:1. | Reduce pressure by staging with a second PRV. | |
| Water hammer. | Install a steam trap at the reducing valve inlet. | |
| Fast closing valve near the PRV. | Provide as long a distance as possible between the two valves. | |
| Others | Springs or diaphragms are damaged. | Replace all damaged springs or diaphragms. |
Disassembly Caution
Be sure that the isolation valves at the inlet and outlet side of the pressure reducing valve are closed and all internal pressure has been relieved before disassembly of the valve.
Disassembly
Pilot Valve Disassembly:
- Loosen the lock nut (10) and turn the adjusting screw (9) to release the spring (8) to no compression.
- Remove the bolts (33) of the spring chamber (4). Remove the spring chamber, spring, top spring plate (6), bottom spring plate (7), and diaphragm (5).
- Remove the pilot valve assembly (19 and 20).
Piston Disassembly:
- Remove the bolts (34) of the pilot body (2). Pick up the spindle (18), and remove the piston ring (16) and the inner ring (17).
Main Valve Disassembly:
- Remove the bolts (35) of the bottom cover (3). Remove the bottom cover, main valve spring (13), and main valve (11).
Reassembly
- Make sure that the main valve and seat, and pilot valve and seat have no flaws. Even a small flaw on the valve or seat may cause leaking.
- Make sure the sliding movement of the piston and cylinder is smooth.
- Be sure to replace all gaskets and diaphragms.
- Reassemble in the reverse order of disassembly.
Lapping Procedure for Main and Pilot Valves
GP-1000 Lapping Procedure for Pilot Valve:
- Remove the GP-1000 pilot spring chamber (4), spring (8), plates (6 and 7) and diaphragm (5).
- Remove the pilot valve assembly (19 and 20) and disassemble.
- Take out the pilot stem and valve (which is one piece). Apply a thin layer of lapping compound (800 grit) on the area of the valve where the valve meets the seat. Place the pilot valve against the seat and by hand, rotate the valve back and forth against the seat. Push firmly. After approximately five minutes, the surface will be clean. Wipe all excess compound off.
- Reassemble the pilot valve assembly back into the pilot body. Test the valve to make sure there are no leaks.
GP-1000 Lapping Procedure for Main Valve:
- Remove the bottom cover (3) from the body (1).
- Remove the main valve spring (13). Check gasket for wear.
- Disassemble main valve (11). Apply a thin layer of lapping compound (800 grit diamond-based recommended) around the radius edge of the main valve where the valve and seat meet. Place the main valve onto its seat (12) and by hand rotate back and forth. Push firmly. For a new valve and seat, it takes approximately 20-40 minutes to create a new clean surface.
- Reassemble and test the valve for leaks.
- Verify the valve has been properly lapped by air testing before putting it back into service. Hook up air supply to the inlet to simulate operation. Adjust screw to shut down simulated flow. Tightly cover the outlet with your hand to feel for leakage. If air pressure is felt, the lapping procedure needs to be repeated.
