Do all these valves need to be closed completely during parking for maintenance? If the electric valve in the middle is turned off in the DCS, is it okay not to turn off the local front and rear control valves? It’s a low-pressure steam pipeline, with steam flowing continuously; today I saw something at that flange again
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Do all these valves need to be closed completely during parking for maintenance? If the electric valve in the middle is turned off in the DCS, is it okay not to turn off the local front and rear control valves? It’s a low-pressure steam pipeline, with steam flowing continuously; today I noticed dripping water at that flange.
These two manual valves at the beginning and end are there for maintenance purposes; you need to close them. Moreover, it seems that the stainless steel pipe section at the front, which lacks insulation, is leaking, so it’s even more necessary to close those valves – both at the beginning and at the end. Moreover, ordinary control valves are not reliable even when the computer is completely turned off. . . Especially with control valves that have been in use for many years, internal wear and leakage often occur.
That’s right; it’s just a steam pipe. I guess the leakage in the flange is caused by condensation water from steam.
I agree with what was said on the second floor. Also, I wonder if this electric valve has been included in your maintenance plan? Since maintenance is being carried out while the equipment is shut down, wouldn’t it be beneficial to take this valve into consideration as well to improve the stability of the equipment?
Thank you, that’s exactly right. It should be repaired. Otherwise, steam will leak in the future.
If it is for parking and maintenance, generally only the control valve needs to be closed; the upstream and downstream valves do not necessarily have to be closed… unless that control valve needs to be taken out for inspection
This flange is easy to install, but it leaks very easily; even minor scratches on the sealing surface can cause problems. Why doesn’t the valve have insulation? It’s a waste of energy in that case
Where to carry out the maintenance? Manual valves are used during maintenance; they must be closed, and it’s steam as well
1. For the maintenance of the main unit, the media connected to the outside world must be isolated; from a safety perspective, physical isolation is necessary, such as disconnecting pipelines or installing blind flanges. 2. Automatic control valves have a low level of safety assurance, and the uncertainty in their control power can affect the safety and reliability of these valves