What materials are acceptable for washers in fire fittings?

Washers are typically made from vulcanized natural or synthetic rubber, or specific grades of leather, depending on the application and joint type.

Which specific fire fighting water fittings do these washers apply to?

They are designed for delivery hose couplings, suction hose couplings, branch pipes, nozzles, and hydrants.

Why is washer hardness specified?

Hardness is strictly controlled so the washer compresses sufficiently to form a secure seal, but resists permanently deforming or blowing out under high operating water pressure.

IS 937

: 1981

Specification for Washers For Water Fittings For Fire Fighting Purposes

CurrentSpecializedSpecificationFire Safety · Fire Fighting

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This standard specifies the requirements for materials, dimensions, and testing of washers used in water fittings for fire fighting purposes. It ensures that critical components like hose couplings, branch pipes, and hydrants maintain leak-proof joints under high water pressure during emergencies.

Specification for Washers For Water Fittings For Fire Fighting Purposes

Quick Reference Values

Hardness of rubber washers60 to 75 IRHD

Tensile strength of rubber (min)10 MPa

Elongation at break (min)250%

Practical Notes

Regular inspection and replacement of rubber washers is critical, as they tend to harden, crack, or perish over time, leading to dangerous leaks during fire emergencies.

Ensure the washer dimensions precisely match the coupling sizes specified in IS 901 and IS 903 to guarantee a watertight seal.