How do we test the tightness of the valve

Date：2021-04-19 08:47:46 Hits：568

Under normal circumstances, our valves need to be tested for gas tightness before leaving the factory to ensure that their leakage is within the specified range.

There is no “ZERO LEAKAGE”

There are actually six different seat leakage classifications defined by ANSI/FCI 70-2 2006 (European equivalent standard IEC 60534-4)

The most commonly used are

CLASS IV

CLASS Vl

CLASS IV is also known as metal to metal. It is the kind of leakage rate you can expect from a valve with a metal plug and a metal seat.

CLASS Vl is known as soft seat classification. Soft Seat Valves are those where either the plug or seat or both are made from some kind of composition material such as Polytetrafluoroethylene (PTFE) or similar.

Leakage Class Designation	Maximum Leakage Allowable	Test Medium	Test Pressure	Testing Procedures Required for Establishing Rating
I	x	x	x	No test required
II	0.5% of rated capacity	Air or water at 50 - 125^o F (10 - 52^oC)	45 - 60 psig or maximum operating differential whichever is lower	45 - 60 psig or maximum operating differential whichever is lower
III	0.1% of rated capacity	As above	As above	As above
IV	0.01% of rated capacity	As above	As above	As above
V	0.0005 ml per minute of water per inch of port diameter per psi differential	Water at 50 to125^oF (10 to 52^oC)	Maximum service pressure drop across valve plug not to exceed ANSI body rating	Maximum service pressure drop across valve plug not to exceed ANSI body rating
VI	Not to exceed amounts shown in the table below	Air or nitrogen at 50 to 125^o F (10 to 52^oC)	50 psig or max rated differential pressure across valve plug whichever is lower	Actuator should be adjusted to operating conditions specified with full normal closing thrust applied to valve plug seat

Port Diameter		*Bubbles per minute*	*ml per minute*
*inches*	mm	*Bubbles per minute*	*ml per minute*
1	25	1	0.15
1 1/2	38	2	0.30
2	51	3	0.45
2 1/2	64	4	0.60
3	76	6	0.90
4	102	11	1.70
6	152	27	4.00
8	203	45	6.75
10	254	63	9
12	305	81	11.5

This is the ANSI B16.104

In the test, the leakage of the valve is lower than Class VI, we will consider it as a qualified product.

Customer satisfaction is our greatest pursuit.

工作时间

早9:00 - 晚18:00

周六日休息