Problems with diaphragm valves
Thread Content
Hello everyone. I’ve run into a problem recently: acid is leaking out from the small hole on the side of the diaphragm valve. After blocking that hole, acid still leaks through the valve stem. This hole isn’t used in normal operations. What is the purpose of the small hole on the side of the diaphragm valve? Please help everyone; thank you all in advance.
I’m not sure what the small hole the original poster is referring to is Are there any photos? The small hole you’re referring to might be a leak in the diaphragm, causing the medium to leak.
It’s ventilating; in your case, the diaphragm is likely damaged
You’d better post a photo! Because it’s hard to get a clear indication just based on this! We’re not able to give you an answer either!
The breathing hole is used to connect with the atmosphere, preventing a negative pressure from forming in the diaphragm chamber when the valve stem moves. If acid leaks, it must be the diaphragm that is damaged; replace it promptly.
Is there such a small hole? There is only a small hole at the valve stem. There was also an iron block stuffed inside.
What are the consequences of creating negative pressure? Could you explain it in detail?
That small hole is a breathing hole; it ensures that no air pressure builds up or creates a negative pressure in the upper part of the valve cover when operating the actuators or handles above and below. In short, its purpose is to make the operation easier. The acid leakage you mentioned must be caused by a damaged diaphragm, or by loose bolts connecting the diaphragm; among these, a damaged diaphragm is the most likely cause. Check it; just replace it with a new diaphragm. As a suggestion as well, for diaphragm valves in critical areas, it is best to use reliable imported or domestic brands to ensure safety.