1、阀体孔对O形圈槽的同轴度超过规定值时，O形圈放在槽内，一侧压缩量很大，另一侧压缩量较小，轻者发生漏油，超差严重时，往阀孔内装阀芯时会将O形圈切掉半圈或一圈。在试验台上作出厂试验，由于时间短、油温低又无背压，不会发现漏油，当在成型液压机设备上使用一段时间后就开始漏油。
2. The coaxiality of the O-rings at both ends of the valve body and the main valve hole is qualified. The chamfer at both ends of the valve core should be 15 ° and 20 °. If it is greater than the specified value, the O-rings will also be broken.
3、两者都是合格的，在装配时未向阀孔、O形圈及阀芯上涂润滑油(进口润滑油使用误区)，往四柱液压机阀体装阀芯时也可将O形圈切掉一块。
To prevent the molding hydraulic press control valve oil leakage, from the processing and assembly of the two processes to start, to ensure that the hydraulic components do not leak.