What is the maximum permissible water absorption for vitreous china?

0.5 percent by mass, which ensures the material is highly impermeable and hygienic.

What is the acceptable dimensional tolerance for these sanitary appliances?

Unless specified otherwise, a tolerance of ±4 percent is allowed for dimensions above 75 mm.

Are crazing defects acceptable on the glazed surface?

No, the glazed surface must be completely free from crazing or significant blemishes.

IS 2556 Part 1

: 1982

General requirements for water meters - Part 1: Cold water meters (rotary piston type)

CurrentFrequently UsedSpecificationBIMMEP · Water Supply and Plumbing

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Specifies the general requirements, quality of materials, dimensional tolerances, and inspection criteria for vitreous china sanitary appliances used in plumbing and sanitation.

Specifies general requirements for cold water meters of the rotary piston type for domestic and industrial use.

Quick Reference Values

max water absorption by mass0.5%

general dimensional tolerance±4%

crazing test autoclave pressure0.34 MPa

Practical Notes

Dataset correction: IS 2556 is the standard for Vitreous Sanitary Appliances. The provided title 'Water Meters' is a mismatch (Water Meters are covered under IS 779).

Always verify water absorption test results are strictly under 0.5% to ensure the material qualifies as true vitreous china.

Account for the standard ±4% dimensional tolerance during the initial plumbing layout and rough-ins to avoid installation misalignments.