Bleed Valves and Purge Valves

Oct 25, 2026

Swagelok bleed valves and purge valves provide controlled venting of pressure and removal of system fluids for instrumentation and control devices. The content covers working pressure and temperature limits, compatible wetted materials, and key construction features such as a back stop screw, vent tube, and chrome-plated stem threads. It also includes pressure-temperature rating tables, dimensions and ordering information for multiple end connection types, and testing guidance including low fugitive emission certification criteria and factory test conditions.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages5

Reading Time13 min

AccessFree to download

Bleed Valves and Purge Valves

Bleed Valves

Materials of Construction

Pressure-Temperature Ratings

Dimensions

Ordering Information

Low Fugitive Emissions and Testing

Purge Valves

[swagelok. com](swagelok. com) Bleed Valves and Purge Valves Bleed Valves ■ Working pressures up to 10 000 psig (689 bar) ■ Temperatures up to 850°F (454°C) ■ 316 stainless steel, carbon steel, alloy 400, or alloy C-276 materials Purge Valves ■ Working pressures up to 4000 psig (275 bar) ■ Temperatures up to 600°F (315°C) ■ 316 stainless steel, brass, or carbon steel materials 2 Bleed Valves and Purge Valves Bleed Valves Swagelok bleed valves can be used on instrumentation devices such as multivalve manifolds or gauge valves to vent signal line pressure to atmosphere before removal of an instrument or to assist in calibration of control devices. ■ Compact for convenient installation ■ Male NPT and SAE end connections ■ Orifice of 0.125 in. (3.2 mm); flow coefficient (Cv) of 0.25 Materials of Construction Back stop screw prevents accidental stem disassembly Vent tube directs excess liquid or gas from system lines Chrome-plated stem threads and tip enhance valve life | Component | Valve Body Materials | | | | | --- | --- | --- | --- | --- | | | 316 SS | Steel | Alloy 400 | Alloy C-276 | | | Material Grade/ASTM Specification | | | | | Stem | Chrome-plated 316 SS/A276 | | Alloy 400/
B164 | Alloy C-276/
B574 | | Body➀ | 316 SS/A479 | 1018➁/A108 | | | | Back stop
screw | 316 SS | | Alloy 400 | | | Vent tube | 316 SS/A269 | | Alloy 400/B165 | | | Lubricant | Nickel antiseize, hydrocarbon carrier | | | | Wetted components listed in italics. ➀ Male SAE body has fluorocarbon FKM O-ring. ➁ Carbon steel bodies are plated with cadmium yellow dichromate for corrosion resistance. Pressure-Temperature Ratings➀ | Material | 316 SS | Steel | Alloy 400 | Alloy C-276 | | --- | --- | --- | --- | --- | | Temperature, °F (°C) | Working Pressure, psig (bar) | | | | | –65 (–53) to 100 (37)
200 (93)
300 (148)
400 (204) | 10 000 (689)
9 290 (640)
8 390 (578)
7 705 (530) | 10 000 (689)
9 110 (627)
8 860 (610)
8 555 (589) | 10 000 (689)
8 800 (606)
8 240 (567)
7 960 (548) | 10 000 (689)
9 120 (628)
8 425 (580)
7 800 (537) | | 450 (232)
500 (260)
600 (315)
650 (343) | 7 435 (512)
7 165 (493)
6 770 (466)
6 660 (458) | 8 315 (572)
—
—
— | 7 940 (547)
7 920 (545)
—
— | 7 545 (519)
7 290 (502)
6 850 (471)
6 665 (459) | | 700 (371)
750 (398)
800 (426)
850 (454) | 6 480 (446)
6 335 (436)
6 230 (429)
6 085 (419) | —
—
—
— | —
—
—
— | 6 520 (449)
6 375 (439)
6 265 (431)
6 155 (424) | ➀ Ratings based on all metal seals. Ratings limited to: ■ –20°F (–28°C) min with steel. ■ 450°F (232°C) max with SAE end connections using fluorocarbon FKM O-rings. ■ 4568 psig (314 bar) max with SAE end connections. [swagelok.com](swagelok.com) Bleed Valves and Purge Valves 3 Bleed Valves Dimensions Dimensions, in inches (millimeters), are for reference only and are subject to change. 7/16 in. hex (316 SS, steel, alloy 400) 7/16 in. flat (alloy C-276) | Inlet End
Connection | | Ordering
Number | Dimensions, in. (mm) | | | | | --- | --- | --- | --- | --- | --- | --- | | Type | Size | | A | B | C | D | | Male
NPT | 1/8 in. | SS-BVM2 | 1.34 | 0.94 | 0.41 | 0.75 | | | 1/4 in. | SS-BVM4 | (34.0) | (23.9) | (10.4) | (19.1) | | | 3/8 in. | SS-BVM6 | 1.47 | 1.03 | 0.44 | 0.88 | | | 1/2 in. | SS-BVM8 | (37.3) | (26.2) | (11.2) | (22.4) | | Male
SAE➀ | 1/4 in. ,
7/16-20 | SS-BVST4 | 1.34
(34.0) | 0.94
(23.9) | 0.41
(10.4) | 0.69
(17.5) | | | 1/2 in. ,
3/4-16 | SS-BVST8 | 1.47
(37.3) | 1.03
(26.2) | 0.44
(11.2) | 0.63
(16.0) | | Male
ISO➁ | 1/4 in. | SS-BVM4RT | 1.34
(34.0) | 0.94
(23.9) | 0.41
(10.4) | 0.75
(19.1) | | | 1/2 in. | SS-BVM8RT | 1.50
(38.1) | 1.06
(26.9) | 0.44
(11.2) | 0.92
(23.4) | ➀ Adapts to SAE straight thread boss and SAE J1926/1 boss. ➁ See specifications

FAQs

What are Swagelok bleed valves used for?

They vent signal line pressure to atmosphere before removing an instrument or assist in calibration of control devices. They can be applied on instrumentation devices such as multivalve manifolds or gauge valves.

What pressure and temperature ranges do the valves support?

The document lists working pressures up to 10,000 psig (689 bar) for bleed valves and up to 850°F (454°C) depending on material and ratings. It also provides additional rating limits for lower temperatures and end-connection O-ring constraints.

How are low fugitive emissions and factory tests addressed?

API 624 tests are referenced to verify methane leakage does not exceed 100 ppm during testing, and certificates for low emissions service may be available. Each bleed valve is factory tested with nitrogen at 1000 psig (69 bar) and includes seat and shell leakage acceptance criteria.

Oct 25, 2026

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