1 Scope
2 Normative references
3 Definitions
3.1 Safety valve
3.2 Pressure
3.3 Lift
3.4 Flow area
3.5 Flow diameter
3.6 Discharge capacity
3.7 Notified body
3.8 Inspection authority
3.9 Nominal size
4 Design, materials and construction
4.1 General
4.2 End connections
4.3 Materials
5 Integrity testing in the factory
5.1 Purpose
5.2 General
5.3 Hydraulic test
5.4 Pneumatic testing
5.5 Adjustment of cold differential test pressure
5.6 Seat leakage test
6 Operating and flow characteristic tests
6.1 General
6.2 Operating characteristics
6.3 Flow characteristics
6.4 Determination of coefficient of discharge
6.5 Certification of valves
7 Determination of safety valve performance
7.1 Determination of coefficient of discharge K[d]
7.2 Critical and subcritical flow
7.3 Discharge capacity at critical flow
7.4 Discharge capacity for any gas at subcritical flow
7.5 Discharge capacity for liquid
8 Sizing of safety valves
8.1 Valves for gas and vapour
8.2 Calculation of capacity
9 Marking and sealing
9.1 Marking on the body of a safety valve
9.2 Marking on an identification plate
9.3 Sealing of a safety valve