The DN50 purge gate valve for 1.0MP steam keeps leaking; it has been replaced three times – what’s the issue?
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The DN50 purge gate valve for 1.0MP steam keeps leaking; it has been replaced three times (almost once a month). What’s the reason?
First, there are quality issues with the valves in this batch themselves； Second, the issue of valve material selection
By using a stop valve, the gate valve does not open fully during use, and high-speed fluids can erode the valve disc.
The DN50 purge gate valve for 1.0MP steam is constantly leaking; replace it with a globe valve
It is recommended to attach a photo of the site to check the piping there Including what medium is behind the valve?
It might be due to a quality issue with the material of the sealing surface on the part of the manufacturer. I previously used J41H-16C check valves for low-point drain bypasses on the pipelines for low-pressure steam (0.8 MPa, 200°C); however, these valves started leaking internally after a short time. After temporarily replacing them with valves of the same model from another manufacturer, no more internal leaks occurred. I guess it’s a quality issue with the valve.
Try a different deadline, or switch to a different manufacturer
Personally, I think it’s certain that the relief valve on this steam line doesn’t close properly; it’s just a matter of how long it takes. Of course, if you’ve never turned it on or off before, it can be ensured that there will be no leaks; but once it’s been used, it’s hard to keep it sealed properly. I think this is related to the steam as the medium used
During use, blowdown gate valves are subject to the presence of debris in the pipes caused by steam; over time this can damage the surface of the gate. Additionally, since the gate of such valves is fixed within a groove, some debris remains in that groove, preventing the gate from being pressed tightly against its seat, which leads to leaks. For main steam valves, regular inspections are necessary; whereas for distribution valves, replacing them with globe valves should resolve the issue.
Gate valves are not really recommended for use in steam pipelines; I suggest trying a globe valve instead. Be sure to choose one with a hard-sintered surface to prevent damage from steam erosion