What kind of pressure gauge gasket to use
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For PN10.0 and applications above 200 degrees, what kind of gasket should be used for pressure gauges? Using red copper does not work well as it often leads to leaks; does anyone have any better suggestions?
On my waste heat boiler, I use pressure gauges rated for PN10.0 and operating at 380 degrees; the gaskets used are made of red copper (after quenching), and they perform quite well. It would be better if you checked the installation status.
Gaskets made of red copper need to be annealed; aluminum gaskets can also be used
According to HG20610-97, for steel pipe flanges using spiral gaskets (European system), metal spiral gaskets can be used
The gasket mentioned upstairs seems inappropriate; pressure gauges are usually connected using M20*1.5 threads, and quenched copper gaskets or aluminum gaskets can be used. If the temperature does not exceed 250 degrees, PTFE gaskets can also be used.
Copper pads at 200 degrees must be annealed; otherwise they cannot be pressed tightly as they are too hard
Shouldn’t a pressure gauge be fitted with a gasket? ? Haven’t heard of it
An annealed copper gasket is generally used for high pressures
An annealed copper gasket or an aluminum gasket can be used. As for what the original poster said about copper gaskets not working well and causing leaks frequently, one should actually consider whether the installation method is correct; too many copper gaskets should not be used – one is sufficient. But it is best to use new gaskets when reinstalling a pressure gauge after removing it. Check it each time after the system is depressurized and before re-pressurizing it. Previously, we required that tightening be carried out while the system was under pressure once it had reached a certain pressure level, and generally there were no issues. This post was last edited by ZZD109 on 2009-4-6 21:00]
It’s better to use quenched copper gaskets. Also, remember to heat-seal ； Moreover, the pressure gauge should be installed with an expansion bend.
Shims must be used. In the past, rubber-asbestos gaskets were commonly used when pressure was low, but asbestos is no longer allowed to be used, so polytetrafluoroethylene gaskets are used in most cases. If the temperature is too high, flexible graphite gaskets or copper gaskets can be considered; metal wound gaskets are not suitable and cannot be used.
Answer to User on Floor 19: For pressure gauges with threaded connections, if it is a pipe thread with threaded sealing, such as NPT (American standard), Rc (ISO, British standard, Japanese standard, etc.), ZG (Chinese standard), the threads themselves provide sealing; no gaskets are needed. You can wrap Teflon tape around them (or not) and then tighten them. For pipe threads that do not provide a threaded seal, such as G (national standards, ISO, British standards, Japanese standards, etc.), the threads themselves do not have any sealing function; it is necessary to use sealing materials such as gaskets. For standard metric threads, such as M12x1.5, the thread itself does not provide any sealing function, so gaskets are required. For the gauge gasket mentioned by the poster, under such processing conditions, a graphite-wrapped metal gasket can be used.