ISO 5171:2019 pdf free
ISO 5171:2019 pdf free.Gas welding equipment – Pressure gauges used in welding, cutting and allied processes
The test shall be carried out using a test pressure gauge of at least class 0,6 and at a temperature of (23±2) °C (STP conditions). Each sample gauge shall be tested over its entire scale, the pressure being increased in at least five steps equally spread over the measurement range to the maximum operating pressure (see Figure 6). The pressure shall then be increased to the maximum scale reading after which it shall be decreased in at least five steps equally spread over the measurement range. The accuracy shall be compared only over the operation pressure range (see 5.2.1.1). The pressure gauge may be lightly tapped during this test.
If a pointer stop is incorporated, the accuracy shall meet the conditions of class 2,5 at the bottom of the scale.
The requirements for this test are given in Clause 5. The complete pressure gauge shall be connected to a gas source of a pressure equal to its maximum scale reading or 30 MPa (300 bar),whichever is the greater. Pressurize the pressure gauge steeply through the inlet. The inlet pressure (measured in front of the test sample) shall be achieved to more than 95 % of the maximum scale reading pressure or 28,5 MPa (285 bar), whichever is the greater, within 20 ms.
If gas is vented during this test, note if the gas is vented safely or not and whether any parts are thrown from the gauge. If the requirements from 5.2.1.5 are not fulfilled, stop the test. If the requirements from Clause 5 are fulfilled, the test is passed.
Following the overpressure resistance test, the leakage test shall be carried out at a pressure corresponding to its maximum scale reading. The leakage test shall be performed according to the method in ISO 9090 or equivalent measuring methods. The total leakage rate shall be measured.
After test A, reduce the pressure equivalent to 90 % of the maximum scale reading and carry out the leakage test again. The leakage test shall be performed according to the method in ISO 9090 or equivalent measuring methods. The total leakage rate shall be measured.ISO 5171 pdf free download.
