【Weekly Topic】What type of valve is best for on-site drain valves? Why? (2011620--2011625)
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This post was last edited by shmily327 on 2011-6-20 23:27. What type of valve is best for use as a local drain valve? Why?
For on-site drain valves, it is best to use globe valves connected by flanges (rather than socket-welded ones) – the main purpose is to facilitate maintenance in case there are problems with the drain valve, without the need to shut down the system. Because on small pipe diameters, globe valves provide better sealing performance than gate valves.
Agreed; especially in the case of internal leakage in the valve, it’s simply sufficient to use a blind flange to seal it off. Sometimes, internal valve leakage prevents maintenance without shutting down the system
Globe valves can also be chosen when the pressure is low and the hazard of the medium is not significant.
Actually, either a gate valve or a globe valve can be chosen. The design institutes I was in contact with before basically used gate valves. And they are all socket-welded valves! 800BL. In our current design process, socket welding of gate valves is also used. If the medium is highly corrosive or poses a significant risk, a dual-valve system or a plug can be used. Furthermore, compared to flanged valves, butt-welded valves result in a smaller overall size, which prevents the pipeline height from exceeding EL+500BOP due to the need for a backflow preventer.
Globe valves are generally used for drain valves; the main purpose is to facilitate maintenance in case there are problems with the valve, without the need to shut down the system. They also serve a regulating function, making it easier to prevent unwanted substances from being discharged
Of course, it is best to use a globe valve with flange connections, as this facilitates maintenance in case there are problems with the drain valve. In some cases, gate valves can also be used; under no circumstances should ball valves be used
A gate valve can also be used; just add an extra plug.
It can be determined based on the properties and pressure of the medium flowing in the pipeline. Nowadays, gate valves are commonly used in such installations, connected via flanges; if internal leakage occurs, a blind plate can be installed.
We mainly use globe valves here, whether for steam, circulating water, or other fluids; only in a few cases do we use gate valves, and when the pressure is relatively high, we use two gate valves.
Globe valves with flange connections are generally used; if internal leakage occurs, a plug is installed