This international standard specifies test to confirm the pressure-containing capability of the shell of an industrial valve under pressure, and to verify the tightness and pressure-retaining adequacy of the valve seat and closure mechanism

Fluid	Allovable leakage mm³/sec
	Rate A (a	Rate B (b	Rate C	Rate D (c	Rate E (d	Rate F (d	Rate G (d
Liquid	No visually detectable leakage for the duration of the test	0.01 x DN	0.03 x DN	0.1 x DN	0.3 x DN	1 x DN	2 x DN
Gas		0.3 x DN	3,0 x DN	30 x DN	300 x DN	3000 x DN	6000 x DN

Notes:

a) Leakage rate A is intended to apply for soft seat, e.g., elastomeric or polymeric valve closure elements.

b) Leakage rates B possibly will apply for metal seated valves on more critical services.

c) Leakage rates D possibly will apply for metal seated check valves.

d) Leakage rates E to G possibly will apply metal seated valves produced for a warehousing operation, stock or sale via a stock list.