一、 alloy steel valve and High pressure valve should be checked by disintegration no less than once for 10% of each batch. Equipment .if unqualified be found , the all should be checked by disintegration one piece at once.
二、When alloy steer valve and high pressure valve be checked by disintegration ,the following terms should be abided :
1、 inner parts of alloy steel valve and those of high pressure valve should on spectral analysis .  and the material should be concrete。
2、 the seat should be combined with body firmly.
3、 There is no defect and the connection between spool and seat should be OK.
4、 There should be flexible and reliable connection between stem and spool.
5、 Stem should have no curl, no rust and suit to filler lid. And the thread have no problem.
6、 The lid and the body combined well.
7、 Gasket , filler , bolt and other thing are completed with no fault.
三、the following terms should be obeyed when want to change filler:
1、 the interface of filler oblique by 45 degree . and the upper and the  lower clamp tightly.
2、 Use the special tools or tire tools Press-fit , rather than screwdriver when fix the filler. The first circle filler should be pressed good.
3、 Each interface of circle filler should have 120 degree apart from those of the others.
4、 Not to press too tightly . after press the filler one or two circles , the handwheel should be turned to make stem up-down or rotate.
5、 Force should be uniform when fasten the filler lid . the space between lid and stem should be kept the same with around in case of inclining up . the lid deep into the filler no more than 5 mm and keep extra space for press tightly.