BS EN 969:2009 pdf download
BS EN 969:2009 pdf download.Ductile iron pipes, fittings, accessories and their joints for gas pipelines一 Requirements and test methods.
6.2 Straightness of pipes
The pipe shall be rolled on two gantries or rotated around its axis on rollers, which in each case are separated by not less than two-thirds of the standardized pipe length.
The point of maxwnum deviation from the straight axis shaM be determined and the deviation measured at that point.
6.3 TensIle testing
6.3.1 Samples
The thickness of the sample and the diameter of the test bar shall be as given In Table 9.
6.3.1.1 Centrifugally cast pipes
A sample shall be cut from the spigot of the pipe. This sample may be cut parallel with or perpendicular to the
pipe axis, but in case of dispute the parallel with axis sample shall be used.
6.3.1.2 PIpes not c.ntrlfugally cast, fittings and accessories
At the manufacturer’s option, samples shall be either cast inteally with the castings or cast separately. In the latter case they shall be cast from the same metal as that used for the castings If the castings are subjected to heat treatment, the samples shall be subjected to the same heat treatment cycle
6.3.2 Preparation of test bar
A test bar shall be machined from each sample to be representative of the metal at the mk thickness of the sample, with a c,1indricaI part having the diameter given in Table 9.
The test b shaM have a gauge length equal to at least five times the nominal test bar diameter. The ends of the test bar shall be such that they will fit the testing machine.
The surface roughness profile of the cindricaI part of the test bar shaM be such that Rz 6,3.
If the specified diameter of the test bar is greater than 60 % of the measured minimum thickness of the sample, it is allowed to machine a test bar with a smaller diameter or to cut another sample is a thicker part of the pipe.
6.3.4 Test results
Test results shal comply with Table 5. If they do not comply. the manufacturer shall:
a) Wi the case where the metal does not achieve the required mechanical properties, investigate the reason and ensure that all castings In the batch are erther re-heat treated or rejected. Castings which have been re-heat treated ore then re-tested In accordance with 6.3.
b) ii the case of a defect in the test bar, carry out a further test. If it passes, the batch is accepted; if not, the manufacturer has the option to proceed as ii a) above.
The manufacturer may limit the amount of rejection by making tests until the rejected batch of castings is bracketed. In order of manufacture, by a successful test at each end of the interval in question
6.4 Brinell hardness
When Bnnell hardness tests are carried out (see 4.3.2), they shall be performed either on the casting in dispute or on a sample cut from the casting The surface to be tested shall be suitably prepared by local grinding to ensure a flat surface and the test shall be carried out in accordance with EN ISO 6506-1 usrng a ball of 2,5 mm or 5mm or 10mm diameter,
6.5 Works leak tightness test for pipes and fittings
6.5.1 General
Pipes and fittings shall be tested for leak tightness using air or water.
They shall be tested In accordance with 6.5.2 or 6.5.3 respectively. The type of test required shall be on the basis of this standard.
The test apparatus shall be suitable for applying the specified test pressures to the pipes and/or fittings. It shall be equipped with an industrial pressure gauge with an error limit ±3 %.
6.5.2 Centrifugally cast pipes
When the internal hydrostatic pressure test is carried out, the pressure shall be raised steadily until it reaches the works hydrostatic test pressure given in Table 10, which is maintained for a sufficient time to allow visual inspection of the pipe barrel or fitting. The total duration of the pressure cycle shall be not less than 15 s. induding 10 s at test pressure.
