What are the standard pressure ratings covered by this code?

The standard covers two nominal pressure ratings: PN 1.0 (1.0 MPa) and PN 1.6 (1.6 MPa) as per Clause 3.

What is the required body test pressure for a PN 1.0 valve?

The hydrostatic body test pressure is 1.5 MPa (1.5 times PN), held for 5 minutes without leakage (Table 3).

What material is specified for the valve body?

Grey cast iron conforming to Grade FG 200 or FG 260 of IS 210 is specified for the body (Table 1).

Why use a multi-door valve instead of a single-door one?

For large pipe diameters, a multi-door valve has a smaller slam velocity, which reduces water hammer. It also requires less vertical clearance to open fully.

IS 5312

: 2000

Swing Check Type Reflux (Non-Return] Valves for Water Works Purposes, Part 1: Single-Door Pattern

CurrentSpecializedSpecificationBIMWater Resources · Sanitary Appliances and Water Fittings

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This Indian Standard specifies the requirements for multi-door swing check type reflux (non-return) valves from 450 mm to 2000 mm size for water works purposes. It covers materials, principal dimensions, pressure ratings (PN 1.0 and PN 1.6), manufacturing, testing procedures, and marking.

Swing Check Type Reflux (Non-Return] Valves for Water Works Purposes, Part 1: Single-Door Pattern

Quick Reference Values

Applicable Valve Sizes450 mm to 2000 mm nominal size

Standard Pressure Rating (PN 1.0)1.0 MPa

Standard Pressure Rating (PN 1.6)1.6 MPa

Body Test Pressure (Hydrostatic)1.5 times the nominal pressure (PN)

Seat Test Pressure (Hydrostatic)Equal to the nominal pressure (PN)

Body Material SpecificationGrey Cast Iron, Grade FG 200 or FG 260 of IS 210

Seat Ring Material SpecificationLeaded Tin Bronze, Grade LTB2 of IS 318

Practical Notes

Multi-door designs are used in large diameter pipelines to minimize water hammer (slam) and reduce the head-room needed for the doors to open compared to a single-door valve.

Ensure flange drilling patterns match the connecting pipeline flanges, which typically conform to IS 1538.

The arrow marked on the valve body is critical; it must be installed pointing in the direction of the water flow.