Fabricated PVC-U Fittings for Potable Water Supplies - Specification, Part 6: Specific Requirements for Flanged Tail Pieces with Metallic Flanges
2009 Edition

According to IS 10124 (Part 6): 2009, Clause 3.2.2 and Table 1 provide detailed dimensional requirements for PVC-U flanged tail pieces with metallic flanges. These include nominal sizes ranging from 63 mm to 630 mm with specific parameters such as flange diameters (G, D, d), thickness (T), hole count, minimum radii, lengths, and bolt sizes (from M16 to M27). The internal bore diameter (d) typically has a tolerance of +1.0 mm to 0 mm. Tail pieces can be either plain or socketed, with socket dimensions defined in IS 10124 Part 1. These specifications ensure proper sealing and compatibility in potable water piping systems.

As per Clause 3.2.3 of IS 10124 Part 6, the metallic flanges must be manufactured from cast iron with a minimum grade of FG 150 according to IS 210. This material selection guarantees the necessary strength and durability for the flanges. Additionally, marking requirements include manufacturer identification, size and pressure class per IS 4985, along with colour coding to indicate pressure ratings.

Pressure classes for flanged tail pieces are identified through both markings and colour codes. Each fitting is marked with the manufacturer's name or ID, size, and the applicable pressure class as defined in IS 4985. Colour codes correspond to these classes as follows: Class 2 (0.4 MPa) is blue, Class 3 (0.6 MPa) green, Class 4 (0.8 MPa) brown, Class 5 (1.0 MPa) yellow, and Class 6 (1.25 MPa) black. This system facilitates easy visual identification and ensures compliance with safety standards.

Flanged tail pieces may be supplied as either plain or socketed types, depending on mutual agreement between the manufacturer and purchaser, as per Clause 3.2.2.2 of IS 10124 Part 6. When socketed, the socket dimensions must conform to the requirements outlined in IS 10124 Part 1. The dimensional requirements for metallic flanges are detailed in Table 1 and Figure 1 for standard joints, and Table 2 and Figure 2 for elastomeric sealing ring joints, ensuring uniformity and interchangeability.

Manufacturers are required to mark each flanged tail piece clearly and permanently with the manufacturer's name or identification, the size of the tail piece, and the pressure class as specified in IS 4985. Colour coding is applied to denote the pressure class, ranging from blue for Class 2 (0.4 MPa) up to black for Class 6 (1.25 MPa). Additionally, fittings may bear the BIS Standard Mark, indicating conformity with the applicable Indian Standards. These markings ensure traceability, proper identification of pressure ratings, and certification compliance.