Document Center is acquired by Nimonik

Scope

1.1 These test methods cover procedures for testing the sources of gas leaking at the rate of 4.4 10 ¹⁴ moles/s (1 10⁹ standard-cm ³/s at 0C) or greater. These test methods may be conducted on any object that can be evacuated and to the other side of which helium or other tracer gas may be applied. The object must be structurally capable of being evacuated to pressures of 0.1 Pa (approximately 10³ torr).

1.2 Three test methods are described;

1.2.1 Test Method AFor the object under test capable of being evacuated, but having no inherent pumping capability.

1.2.2 Test Method BFor the object under test with integral pumping capability.

1.2.3 Test Method CFor the object under test as in Test Method B, in which the vacuum pumps of the object under test replace those normally used in the leak detector (LD).

1.3 The values stated in SI units are to be regarded as standard. The values given in brackets are for information only.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Significance and Use

Test Method A—This test method is the most frequently used in leak testing components. Testing of components is correlated to a standard leak, and the actual leak rate is measured. Acceptance is based on the maximum system allowable leakage. For most production needs, acceptance is based on acceptance of parts leaking less than an established leakage rate, which will ensure safe performance over the projected life of the component. Care must be exercised to ensure that large systems are calibrated with the standard leak located at a representative place on the test volume. As the volume tends to be large (>1 m³) and there are often low conductance paths involved, a check of the response time as well as system sensitivity should be made.

Test Method B—This test method is used for testing vacuum systems either as a step in the final test of a new system or as a maintenance practice on equipment used for manufacturing, environmental test, or conditioning parts. As with Test Method A, the response time and a system sensitivity check may be required for large volumes.

Test Method C—This test method is to be used only when there is no convenient method of connecting the LD to the outlet of the high-vacuum pump. If a helium LD is used and the high-vacuum pump is an ion pump or cryopump, leak testing is best accomplished during the roughing cycle, as these pumps leave a relatively high percentage of helium in the high-vacuum chamber. This will limit the maximum sensitivity that can be obtained.

Keywords

helium leak test; helium mass spectrometer leak test; hood leak test; leak testing; mass spectrometer leak test

To find similar documents by ASTM Volume:

03.03 (Nondestructive Testing)

To find similar documents by classification:

23.040.99 (Other pipeline components)

This document comes with our free Notification Service, good for the life of the document.

This document is available in either Paper or PDF format.