This standard lays down the requirements for materials, dimensions, and testing of washers used in plumbing fittings for water services, such as bib taps, pillar taps, stop valves, and ball valves. It ensures proper sealing and durability to prevent leaks in water supply lines.
washers for use with fittings for water services
Quick Reference Values
hardness of rubber washers65 to 75 IRHD
max water absorption rubber10 percent by mass
thickness tolerance up to 3mm± 0.2 mm
thickness tolerance above 3mm± 0.3 mm
Practical Notes
Ensure the washer material selected is appropriate for the service temperature; standard natural rubber will degrade rapidly in hot water applications.
Overtightening taps or valves causes excessive compression, often prematurely shearing or crushing the washer even if it meets IS specifications.
For specialized applications like drinking water, ensure the rubber compound is non-toxic and does not impart odor or taste.