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Swagelok LD Series Bulk-Gas Diaphragm Valves

Swagelok® Bulk-Gas Diaphragm Valves (LD Series)

LD series bulk gas diaphragm valves offer a combination of strength, flexibility, and cycle life to support a wide range of ultrahigh-purity shutoff, bulk-gas distribution, and isolation applications.

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LD series diaphragm valves have a welded diaphragm construction using three diaphragms welded to the stem to prevent leakage. No use of springs or threads in wetted areas enable cleaner operation, and a unique stem tip design promotes leak-tight shutoff. Flow coefficients up to 13 and a variety of body materials and configurations are available to meet a range of design specifications.


Working Pressure Up to 300 psig (20.6 bar)
Temperature –20° to 300°F (–28° to 148°C)
Flow Coefficient Up to 13
Body Materials CF3M cast stainless steel, forged and bar stock 316L stainless steel
Diaphragm Material 316L stainless steel
End Connections
Type Swagelok® tube fitting, male VCR® face seal fitting, female NPT, female ISO, tube extension
Size 1/4 to 1 in.; 12 to 25 mm

LD Series Bulk-Gas Diaphragm Valves Catalogs

Locate detailed product information, including materials of construction, pressure and temperature ratings, options, and accessories.

Swagelok flow coefficient (C<sub>v</sub>) calculator for valves

The Right Valve Can Make All the Difference

Use our valve flow coefficient (Cv) calculator to chose a valve sized correctly for your needs.

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