BS ISO 27895:2009 Vacuum technology. Valves. Leak test
BS ISO 27895 specifies methods for the leak testing of vacuum valves used for control of gas flow or vacuum pressure in a vacuum system. It is applicable to vacuum valves that can be closed to leak rates less than 1 × 10−5 Pa m3/s for trace gas. The methods employ a sealing arrangement for the valve body, which is also given. The methods are suitable for the verification of valve specifications.
A valve leak rate less than the nominal leak rate specified by the manufacturer during and after the operation enables the specification of such valve operating conditions as operating pressure range, permissible pressure difference between ports, bake-out temperature or operating temperature, and life cycle.
Contents of BS ISO 27895:
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Requirements
6 Test methods
6.1 Valve seat leak test
6.2 Valve body leak test
6.3 Leak test on minimum and maximum pressures of compressed air for pneumatic valve
operation (optional
6.4 Leak test on minimum and maximum torques of manual valve (optional)
6.5 Leak test in operating temperature range (optional)
6.6 Leak test after baking (optional)
7 Test report
