BS ISO 19892 pdf download Plastics piping systems — Thermoplastics pipes and fittings for hot and cold water — Test method for the resistance of joints to pressure cycling
This International Standard specifies a method for testing the resistance of joints to pressure cycling. Itis applicable to piping systems based on thermoplastics pipes intended to be used in hot and cold waterapplications.
An assembly of pipes and fittings is subjected to water pressure cycling between two positive pressure limits,while being maintained at a specified temperature and inspected for leakage.
NOTE lt is assumed that the following test parameters are set by the reference standard (i.e. the standard makingreference to this International Standard), as applicable (see Clause 4):
a)the test temperature;
b)the number of test pieces;c)the test pressure limits;d)the duration of one cycle;e)the number of cycles.
3.1 Pressurizing device,capable of applying and regulating the water pressure in the test piece in asinusoidal or trapezoidal form between pressure limits as specified in the reference standard.
3.2 Pressure measurement device, capable of measuring the water pressure in the test piece to an accuracyof t5 %.The device measurement shall be capable of producing a record of the sinusoidal or trapezoidal waveform.
3.3Test chamber, capable of maintaining the specified test temperature (see Clause 4) to an accuracy of±2°℃.
3.4 Thermometer(s), capable of checking conformity to the specified test temperature (see 3.3).
3.5 End-sealing device, of appropriate size and sealing method for sealing the non-joined end of the testpiece. The device shall be restrained in a manner which does not exert longitudinal forces on the joints.
A typical test arrangement is shown in Figure 1.
4 Test parameters
Unless specified otherwise in the reference standard, the test parameters given in Table 1 shall apply.
5 Test pieces
The number of test pieces shall conform to Clause 4.
The test piece shall comprise an assembly of pipes and at least one fitting joined in accordance with themanufacturer’s recommended practice.
The free length on each side of the fitting under test shall be not less than either 1,5dn or 300 mm, whicheveris the greater, where dn is the nominal outside diameter of the pipe.
In order to include the required number of pipes and fitting(s),several test pieces may be tested simultaneously,provided the failure of one test piece does not affect the others under test.
6.1 Fill each test piece with water so that all the air is expelled.
6.2 Bring the test piece and water therein to the specified temperature (see Clause 4).
6.3 Condition the test piece at the applicable temperature (see Clause 4) in accordance with Table 2 beforeor after connecting the test piece(s) to the pressurizing device. If subsequent connection is necessary, ensurethat all air is again expelled and that the conditioning has been completed immediately before connection to thepressurizing device.
7.1 Unless specified otherwise in the reference standard, subject the test piece to the applicable pressure limits conforming to Table 3 and for the number of cycles and cycle frequency conforming to Clause 4, while, for the duration of the test and on completion
a) maintaining the test temperature,
b) monitoring the test piece for any signs of leaks, and
c) checking wave form at the start, at regular intervals and at the end of the test and recording them