What is the primary function of a valve conforming to IS 10986?

To allow fluid to flow in only one direction and automatically prevent backflow in a pipeline.

What is the required body test pressure?

The valve body must withstand a hydrostatic pressure of 1.5 MPa for a specified duration without showing any leakage (Clause 7.2.1).

What markings should be present on the valve?

The valve should be marked with the manufacturer's name or trademark, the nominal size (DN), and the direction of flow (Clause 8.1).

Can plastic materials be used for these valves?

Yes, the standard allows for the use of suitable plastic materials, provided they meet the performance requirements and are agreed upon between the purchaser and manufacturer (Clause 4.1).

IS 10986

: 1984

Non-Return Valves for Plumbing Systems - Specification

CurrentFrequently UsedSpecificationBIMMEP · Plumbing Fixtures and Valves

Download PDF BIS Portal Google

This standard specifies the requirements for materials, dimensions, construction, workmanship, and performance testing for non-return (check) valves up to size DN 100 used in plumbing systems. It covers various types like swing and lift check valves, ensuring they prevent backflow effectively in water lines.

Covers requirements for non-return valves (check valves) for use in plumbing systems.

Quick Reference Values

Nominal Pressure (PN)1.0 MPa

Hydrostatic Test Pressure (Body)1.5 MPa (1.5 x PN)

Seat Test Pressure (Air)0.6 MPa

Minimum waterway areaNot less than the nominal bore area of the connecting pipe

Practical Notes

Ensure correct installation orientation as many non-return valves are gravity-assisted and only work in specific orientations (e.g., horizontal or vertical-up flow).

The choice between swing, lift, or other types of check valves depends on the application, fluid velocity, and potential for water hammer.

Regular inspection is recommended as internal components can wear out or get stuck due to debris, leading to failure.