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Brand: Armstrong International
Armstrong GP-2000 External Pilot Steam Pressure Reducing Valve
Description
Large-capacity steam pressure reduction with an external pilot
The Armstrong GP-2000 is a high-performance, externally piloted pressure reducing valve for steam, intended for large capacity requirements. Armstrong lists intermittent service as the typical use, in applications such as heat exchangers, steam coils, rotating dryers, process equipment and heating systems. With 20:1 rangeability the valve is described as accurate to plus or minus 1% of the set pressure from 5% to 100% of flow.
Working parts are hardened stainless steel and renewable in-line. The valve is single seated for dead-end service, meets ANSI Class IV shutoff, and is offered in NPT (1/2 in to 2 in) and flanged (1/2 in to 6 in) connections. Cv runs from 5.0 on the 1/2 in size to 250 on the 6 in size, and a 50% reduced port is available from 1/2 in to 4 in.
Technical specification
| Parameter | Specification |
|---|---|
| Service | Steam |
| Operating principle | External pilot, diaphragm operated, single seated, dead-end service |
| Inlet pressure, NPT connections | 15 to 300 psig (1 to 20 barg) |
| Inlet pressure, 150 lb flanged | 15 to 185 psig (1 to 13 barg) |
| Inlet pressure, 300 lb flanged | 15 to 300 psig (1 to 20 barg) |
| Reduced pressure range, yellow spring (low) | 1.5 to 3 psig (0.10 to 0.21 barg); remove one pilot diaphragm, which halves the chart capacities |
| Reduced pressure range, yellow spring | 3 to 21 psig (0.21 to 1.4 barg) |
| Reduced pressure range, green spring | 15 to 200 psig (1 to 13.8 barg) |
| Maximum temperature | 450 F (232 C) |
| Minimum differential pressure | 7 psig (0.48 barg) |
| Rangeability and accuracy | 20:1; plus or minus 1% of set point from 5% to 100% of flow |
| Shutoff | ANSI Class IV |
| Body | Ductile iron, ASTM A536; colour dark gray |
| Main valve and seat, pilot valve and seat | Stainless steel, AISI 420 |
| Diaphragm | Stainless steel, AISI 301 |
| Connections | NPT 1/2 to 2 in; flanged 150 lb and 300 lb, 1/2 to 6 in |
| Port | Full port; 50% reduced port available for 1/2 to 4 in (divide Cv by 2) |
| Certified drawings | CDY #1008 (GP-2000) and CDY #1007 (GP-2000 Flanged) |
Dimensions, weights and Cv by size
| Size, in (mm) | L NPT, in (mm) | L 150#, in (mm) | L 300#, in (mm) | A, in (mm) | F, in (mm) | H integral, in (mm) | H remote, in (mm) | H1, in (mm) | H2, in (mm) | Weight NPT / 150# / 300#, lb (kg) | Cv |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 (15) | 5-15/16 (150) | – | – | 7-15/16 (200) | 6-7/8 (176) | 15-3/4 (398) | 14-1/4 (362) | 6-3/4 (170) | 9-5/8 (244) | 34 (14) / 36 (15) / 42 (19) | 5.0 |
| 3/4 (20) | 5-15/16 (150) | – | – | 7-15/16 (200) | 6-7/8 (176) | 15-3/4 (398) | 14-1/4 (362) | 6-3/4 (170) | 9-5/8 (244) | 34 (14) / 36 (15) / 42 (19) | 7.2 |
| 1 (25) | 6-5/16 (160) | 5-3/4 (147) | – | 8-15/16 (226) | 7-1/16 (179) | 15-15/16 (404) | 14-7/16 (367) | 6-15/16 (175) | 10 (254) | 44 (19) / 48 (20) / 54 (23) | 10.9 |
| 1-1/4 (32) | 7-1/8 (180) | 6-1/2 (166) | – | 8-15/16 (226) | 7-7/16 (188) | 17-1/8 (434) | 15-1/8 (384) | 7-5/8 (192) | 11-1/8 (283) | 51 (22) / 53 (22) / 59 (25) | 14.3 |
| 1-1/2 (40) | 7-1/8 (180) | 7-7/16 (189) | – | 8-15/16 (226) | 7-7/16 (188) | 17-1/8 (434) | 15-1/8 (384) | 7-5/8 (192) | 11-1/8 (283) | 51 (22) / 55 (23) / 61 (26) | 18.8 |
| 2 (50) | 9-1/8 (230) | 8-9/16 (217) | 9-1/8 (232) | 10-15/16 (276) | 7-11/16 (195) | 19-5/8 (498) | 16 (406) | 8-1/2 (216) | 12-5/8 (321) | 75 (33) / 81 (36) / 84 (36) | 32 |
| 2-1/2 (65) | – | 10-15/16 (278) | 11-1/2 (292) | 13-13/16 (352) | 8-5/16 (211) | 21-3/4 (552) | 17-5/16 (440) | 9-13/16 (251) | 14-3/4 (375) | – / 142 (65) / 150 (65) | 60 |
| 3 (80) | – | 11-3/4 (298) | 12-7/16 (315) | 13-13/16 (352) | 8-3/4 (222) | 22-5/8 (575) | 17-15/16 (456) | 10-7/16 (264) | 15-3/4 (400) | – / 155 (69) / 166 (72) | 78 |
| 4 (100) | – | 13-1/2 (343) | 14-1/8 (359) | 15-13/16 (401) | 9-7/16 (239) | 25-15/16 (658) | 20-1/8 (511) | 12-5/8 (321) | 19-1/4 (489) | – / 247 (112) / 264 (119) | 120 |
| 6 (150) | – | 18-1/8 (460) | 19 (483) | 19-3/4 (502) | – | 31-3/4 (806) | – | 16-1/4 (414) | 26-1/2 (673) | – / 507 (230) / 553 (252) | 250 |
Cv is for the full port; the data sheet notes that the 50% reduced port is available for sizes 1/2 in to 4 in and its Cv is half the value shown. Capacity charts are on page 305 of the Armstrong catalogue as cited by the sheet.
Sizing, installation and where it is used
Pick the spring range that covers the set pressure, check the minimum differential of 7 psig (0.48 barg), and size the port from the capacity chart on page 305 of the Armstrong catalogue, which the sheet cites.
The datasheet lists intermittent steam duty at heat exchangers, steam coils, rotating dryers, process equipment and heating systems; in Gulf plants that means plant steam up to the printed 20 barg inlet limit, reduced to process or heating headers. ANSI Class IV shutoff and stainless working parts suit the intermittent flow.
Spring ranges, port sizes and weights
Three pilot springs are listed. The low yellow spring covers 1.5 to 3 psig (0.10 to 0.21 barg) after removing one pilot diaphragm, which halves the chart capacities. The standard yellow spring covers 3 to 21 psig (0.21 to 1.4 barg) and the green spring 15 to 200 psig (1 to 13.8 barg). The inlet limit depends on the connection: 20 barg for NPT and 300 lb flanged, 13 barg for 150 lb flanged. The maximum temperature is 232 C for all, and the valve needs 0.48 barg of differential to operate.
Cv rises from 5.0 at 1/2 in through 10.9 at 1 in, 32 at 2 in and 78 at 3 in to 250 at 6 in. Weight rises from 14 kg for the NPT 1/2 in valve to 230 kg for the 150 lb flanged 6 in valve and 252 kg for the 300 lb. The reduced port option halves the Cv from 1/2 to 4 in, so a 4 in valve with a 50% port has a Cv of 60 (derived). The integral pilot version is 398 mm tall on the 1/2 in size, against 362 mm for the remote pilot version, which is the shorter of the two.
Selection and installation notes
A pilot-operated reducing valve is sized from the steam flow, the inlet and outlet pressure and the pipe size, not only from the line diameter. Fit a strainer and a separator upstream, keep a straight run of pipe on both sides, provide a relief valve downstream where the standard requires one and warm the line slowly. Set the outlet pressure with the pilot while the system is in use and record the setting.
Information needed for a quotation
Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.
Documents and supply information
The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.
Documents and quotation
The Armstrong data sheet (06/2025 revision) is attached. Related items are in the regulators category. Seven Star LLC is an independent supplier in Muscat; send the size, end connection and flange class, inlet and set pressure and flow and we will confirm the valve and spring range against manufacturer data before we quote.
Datasheets & Documents
- Datasheet Armstrong GP-2000 externally piloted pressure reducing valve data sheet (EN, 06/2025) Download
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About brand
Armstrong International is an American manufacturer of steam, air and hot water system products, founded in 1900 by Adam Armstrong as Armstrong Machine Works in Three Rivers, Michigan. The company first made mechanical potato diggers and brought Armstrong's inverted bucket steam trap to market in 1911. It is still family-owned, now in its fifth generation, and based in Three Rivers.
Seven Star LLC is an independent supplier in Muscat. We list Armstrong steam traps and valves, with the official datasheet attached to each product page, for steam users in Oman and the GCC.
Armstrong International company profile
| Founded | 1900, Three Rivers, Michigan, USA, as Armstrong Machine Works |
|---|---|
| Founder | Adam Armstrong |
| Key invention | The inverted bucket steam trap, on the market from 1911 |
| Ownership | Family-owned, fifth generation |
| Product families | 800 and 1800 series inverted bucket steam traps, float and thermostatic traps, thermodynamic traps, SAGE steam trap monitoring, condensate pumps, humidifiers, steam and water mixing stations |
Milestones
- 1900: Adam Armstrong founds Armstrong Machine Works.
- 1911: The inverted bucket steam trap goes on sale.
- 1928: A new Three Rivers plant is built.
- 1939: A Canadian company is formed.
Armstrong product series
Inverted bucket traps include the 200 Series vertical traps and the 800 Series cast iron traps, which handle dirt and water hammer well and suit drip and process duty. Float and thermostatic traps include the A and AI Series cast iron traps, the FT-4000 stainless trap and the JD, KD, L and M Series ultra-capacity traps for large condensate loads on heat exchangers and coils.
Other traps include the TC-300 carbon steel thermostatic capsule trap, the AB-3000 stainless bimetallic trap with strainer and the CD-33 controlled disc trap rated to 600 psig. The GP-2000 is an external pilot steam pressure reducing valve.
Where Armstrong products are used
Steam main drips and tracer lines, heat exchangers, reboilers, air heating coils, process vessels and steam heating systems in refineries, chemical plants, food plants, hospitals and laundries.
Armstrong International products we list
Ordering Armstrong steam traps: what we need
Send the model, pipe size and end connection, steam pressure and differential, condensate load and the application. For pressure reducing valves give the inlet and outlet pressures and steam flow so the valve can be sized.
Facts checked against Armstrong International's own timeline, October 2026.
Browse Armstrong International products by category: Pipes & Fittings.
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Frequently Asked Questions
What does the GP-2000 do?
It is an externally piloted, diaphragm-operated pressure reducing valve for steam, for large capacity requirements on intermittent service.
What accuracy and rangeability are stated?
20:1 rangeability, and plus or minus 1% of the pressure set point from 5% to 100% of flow.
What are the pressure and temperature limits?
Inlet 15 to 300 psig (1 to 20 barg), maximum temperature 450 F (232 C), minimum differential pressure 7 psig (0.48 barg).
What materials are used?
Ductile iron ASTM A536 body, AISI 420 stainless main and pilot valve and seat, AISI 301 stainless diaphragm.
What connections are available?
NPT in sizes 1/2 to 2 in, and 150 lb or 300 lb flanged in sizes 1/2 to 6 in. Shutoff is ANSI Class IV.
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