Unplasticized PVC Pipes for Potable Water Supplies
2000 Edition

The standard prescribes specific dimensional tolerances primarily outlined in Table 1. The outer diameter at any point must fall within defined minimum and maximum limits, generally ranging from ±0.5% to ±1% of the nominal diameter depending on pipe size and pressure class. Wall thickness tolerances typically allow a ±10% variation from the nominal value. Length tolerances are usually maintained within ±1% of the nominal pipe length. These tolerances ensure compatibility with fittings and maintain the designed pressure ratings.

Chemical safety is assured by mandating that UPVC pipes are manufactured from resins compliant with IS 10148 and IS 10151, which certify suitability for contact with potable water and food. The allowable levels of harmful substances such as lead, mercury, and other toxic organotin compounds are strictly limited to trace amounts. The pipes undergo rigorous testing including extraction tests for heavy metals and sulphated ash content to confirm the absence of contaminants. Markings and color coding further help maintain proper usage and traceability.

To validate performance and durability, the standard requires type tests when introducing new polymer compositions or pipe dimensions. These include internal hydrostatic pressure tests, tensile strength assessments, impact resistance evaluations, and dimensional conformity checks. Hydrostatic tests involve subjecting pipes to elevated pressures at controlled temperatures for specified durations to ensure structural integrity and pressure resistance. Acceptance tests are also conducted on production lots to confirm ongoing compliance.

Pipes must be marked at intervals not exceeding 3 meters with the manufacturer’s name or trademark, nominal outside diameter, pipe class including pressure rating, batch or lot number, and the word 'plumbing' for plumbing pipes. Markings should be applied using ink, paint, or hot embossing on a white background, with inkjet printing in contrasting colors also permitted. Color codes corresponding to pipe classes facilitate quick identification, and pipes may carry the BIS Standard Mark to signify conformity.

The standard emphasizes the use of virgin UPVC resin with additives approved under IS 10148 to ensure safety and durability. Recycled or reworked materials are only allowed if they originate from the manufacturer’s own controlled reprocessing operations and do not compromise the pipe’s mechanical properties or introduce toxic contaminants. Generally, the use of recycled content is discouraged unless it meets all strict quality and safety criteria.

The pipes are designed for water temperatures ranging from 1°C up to 45°C. The maximum safe working stress is 8.6 MPa at 27°C, with pressure classes ranging from 0.25 MPa (Class 1) up to 1.25 MPa (Class 6) at 27°C. For temperatures above 27°C, pressure ratings are reduced according to derating factors specified in the standard. Hydrostatic test pressures vary based on test type but generally include endurance tests at 1.16 times the nominal pressure for 1000 hours at 60°C and acceptance tests at 4.19 times nominal pressure for 1 hour at 27°C.

Socket ends must be manufactured following dimensional specifications and minimum wall thickness criteria provided in the standard's tables and figures. The minimum depth of engagement depends on pipe diameter and is calculated using formulas incorporating nominal outside diameter and actual dimensions. Socket ends should maintain parallelism to the pipe axis to ensure proper sealing. Joint integrity is verified through hydrostatic pressure tests at specified pressures and durations, with different test parameters for pipes below and above 90 mm diameter, ensuring the joint withstands operational stresses.