Valve leakage problem seriously threatens the normal operation of the device, and operation of the valve and its hard to find whether there is leakage, results show that the petrochemical enterprises in the use of a different degree of valve leakage problem.The reasons of disc, seat sealing surface of the material do not conform to the requirements of the use, the machining accuracy is not enough, the valve plate gate valve, the seat of the wedge Angle is not matching, sealing surface or width, alignment, ram does not reach the designated position, closed tightly and other factors.

As for Z41Y - 25, seal face material code should be Y refers to seal in the relatively soft sealing surface hardness material, the corresponding also clearly at least another sealing surface material should be cemented carbide, and actually some valve only in one of the overlaying welding carbide seal face, and another seal face material is carbon steel frame, put into use after the time is not long because of the wear phenomenon of leakage.

In addition, the butterfly valve is selected for the pipe system, and the seat sealing material adopts ptfe.From the point of working condition, demand is not high, atmospheric pressure, but found that the number of the valve in the process of commissioning is lax, severe leakage, so cant normal use, finally had to replace gate valve.The inspection revealed that there was a large gap between the disc and seat in the closed state, and even light.

There may be several reasons for this analysis!The structure design of valve seal is not reasonable or manufacturing and assembly precision cannot meet the requirements;The valve installation does not work as required to withstand excessive force;During the construction process, the sealing effect is affected by welding slag, sand, metal debris and other impurities into the cavity.In fact, the most fundamental reason is that it is not required to do so in the process of manufacturing, transportation or installation.