Specifications Part 1 - Water Supply, Sewerage and Tube Well Works

7.14 Return bendsReturn bends shall be made from heavy tubes, supplied with socket at one endif so specified by the purchaser, and shall conform to the dimensions given inTable 5. IS 1239 (Part-2): 1992. The ends of the bends shall be parallel within±1.5 0 .7.15 Test on Fittings and Sockets7.15.1 The fittings and sockets before they leave the works, shall be subjected toeither of the following pressure tests, as mutually agreed between thepurchaser and the manufacturer:7.15.1.1 The ends of fittings and sockets when subjected to the required pressure, afterhaving been made up wrench tight with the prior application of lubricant, orsealant, or by any other appropriate method shall not show any leakage. Thetest shall be carried out after the fittings and sockets have been screwed andbefore any protecting coating other than galvanizing has been applied.7.15.1.2 The sample size and the acceptance criteria for the pressure test shall be givenin Table 30 below.7.15.2 Expansion Test on SocketsAt the option of the manufacturer any one of the tests described in 7.14.2.1shall be carried out.7.15.2.1 Drift Expanding TestIt shall be carried out on sockets, tubes, blanks, or sockets in accordance withIS 2335: 1963. On a conical mandrel having an included taper on diameter 1 in16 and the minimum increase in outside diameter after expansion shall be asfollows:Nominal Bore mmPercentage of Expansion MinUpto and including 25 2-032 to 40 1.550 to 80 1.0100 to 150 0.5Table No.- 7.10Scale of Sampling and Acceptance Criteria for Pressure TestLot Size Stage SampleSizeCumulativeSample SizeAcceptanceNumberRejectionNumber(1) (2) (3) (4) (5) (6)Upto 1000 First 13 13 0 2Second 13 26 1 21001 to 3000 First 20 20 0 2Second 20 40 1 23001 to 5000 First 32 32 0 3Second 32 64 3 45001 to 10000 First 50 50 1 4Second 50 100 4 510001 and above First 80 80 2 5Second 80 160 6 7Urban Administration & Development Department Page 85