What are the standard pressure classes for IS 4985 pipes?

2.5, 4, 6, 8, 10, and 12.5 kgf/cm² (or bar), which represent the working pressure at 27°C (Clause 6.1).

Can these pipes be used for hot water?

No, this standard is for cold potable water services only. uPVC loses strength and stiffness rapidly at elevated temperatures.

What does the 'OD' of a pipe mean?

OD stands for Outside Diameter. IS 4985 pipes are specified by their nominal outside diameter, e.g., 110 mm OD (Clause 5).

What is the purpose of the reversion test?

The longitudinal reversion test (Clause 8.4) checks for induced stresses from the manufacturing process. A high reversion value (over 5%) indicates poor processing and can lead to long-term performance issues.

IS 4985

: 1994

Unplasticized PVC Pipes for Potable Water Supplies - Specification

CurrentEssentialSpecificationBIMWater Resources · Swimming Pools and Sports Facilities

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This standard specifies the requirements for unplasticized PVC (uPVC) pipes intended for potable water supplies. It covers material composition, dimensions, pressure classifications, performance criteria such as impact strength and pressure resistance, and mandatory marking for pipes.

Specifies requirements for unplasticized PVC pipes suitable for carrying potable water, relevant for pool piping.

Quick Reference Values

Working Pressure Classes2.5, 4, 6, 8, 10, and 12.5 kgf/cm²

Standard Test Temperature27 ± 2 °C

Opacity RequirementShall not transmit more than 0.2% of visible light

Max Longitudinal Reversion5 percent at 150 °C

Minimum Vicat Softening Temperature80 °C

Minimum Wall Thickness for 110mm OD, Class 6 pipe4.2 mm

Practical Notes

Pipe pressure rating (e.g., 6 kgf/cm²) is for water at 27°C and must be derated for higher operating temperatures.

Pipes are designated by their nominal outside diameter (OD). Ensure compatibility with fittings which are typically socketed.

Proper jointing using solvent cement (as per IS 14182) is critical to prevent leaks. Both pipe end and fitting socket must be cleaned and primed before applying cement.