Fabricated PVC-U Fittings for Potable Water Supplies - Specification, Part 7: Specific Requirements for Threaded Adaptors
2009 Edition

IS 10124 Part 7 outlines that threaded adaptors made of PVC-U must be fabricated to ensure compatibility with pipes conforming to IS 4985, except for dimensional criteria. While the adaptors' dimensions deviate from IS 4985 pipe sizes, manufacturers must guarantee that the base pipes meet all other IS 4985 standards including strength and material quality. The adaptors feature standardized pipe threads (such as BSPT or BSPP per IS 554), with critical dimensions including the adaptor's outside diameter, thread length and pitch, and wall thickness at the threaded section to maintain pressure resistance.

As per IS 10124 Part 7 Clause 4.1, each threaded adaptor must bear clear, permanent markings showing the manufacturer's identification, the adaptor size, and the corresponding pressure class defined in IS 4985. Colour coding is used to denote the pressure rating: green for Class 3 (0.6 MPa), brown for Class 4 (0.8 MPa), yellow for Class 5 (1.0 MPa), and black for Class 6 (1.25 MPa). This system facilitates quick visual identification of pressure classifications on site.

Threaded adaptors must be produced from PVC-U pipes that comply with IS 4985 in all aspects except dimensional specifications, with manufacturers ensuring full adherence to other material and performance requirements. For pressure classes 0.25 MPa and 0.4 MPa, adaptors should not be manufactured from pipes of these same classes but rather from 0.6 MPa class pipes. Adaptors can be either plain ended or socketed, with socket dimensions conforming to IS 10124 Part 1. Sizes of 125 mm and above are generally discouraged for threaded adaptors.

Yes. IS 10124 Part 7 allows threaded adaptors to be either plain ended or socketed, provided the socket dimensions meet the requirements of IS 10124 Part 1. The choice between plain ended and socketed types should be mutually agreed upon by the manufacturer and purchaser. However, threaded adaptors are generally not recommended for nominal sizes of 125 mm or larger.

Threaded adaptors under IS 10124 Part 7 are primarily intended for nominal pipe sizes less than 125 mm. Use of threaded adaptors for sizes 125 mm and above is generally discouraged due to manufacturing and performance limitations. The standard provides detailed dimensional data for nominal sizes 63 mm, 75 mm, 90 mm, and 110 mm, including outside diameter ranges, plain portion lengths, wall thicknesses, and thread details to ensure proper function and pressure ratings.