Must cut-off valves be installed at both ends of the blind flange?
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Must cut-off valves be installed at both ends of the blind flange? Do all blind plate switches need to be turned off first? But why are the pipelines of many furnaces equipped with a blind plate directly between two flanges?
It shouldn’t be necessary; it depends on the requirements of the piping system.
In fact, 8-shaped blind plates are not used very often in applications; ordinary blind plates are sufficient. For low pressures, metal sheets can be used as a substitute, but when the pressure is high, the thickness of the blind plate needs to increase, and metal sheets are no longer suitable in such cases; it is then that 8-shaped blind plates become necessary
I think LZ is referring to 8-character blind flanges; it’s impossible for a blind flange to be held in place by two flanges
The fact is that they are used so frequently that there aren’t enough blind flanges available during major repairs; moreover, many areas need to be isolated using blind flanges, and it’s impossible to take all such scenarios into account at the design stage. So in most cases, an iron plate is used and secured with flanges. This was something I saw in a large state-owned chemical company that was built not long ago; I assume other chemical companies are similar in this regard. The design only covers the basic aspects, and many adjustments have to be made on the spot during actual production, of course, all while ensuring safety
This post was last edited by zhanong on 2009-10-28 at 10:02. The 8-character blind plate, used as a proper blind plate, is necessary for industrial production and is primarily applied in the following situations: 1. An 8-character blind plate is generally installed at the point where pipelines enter the plant area； 2. The pipeline is frequently switched between blocked and unblocked states, and leaks are not permitted, as the medium is often toxic or flammable and explosive. 3. Others are installed to facilitate process production and maintenance operations. 8-character blind plates should be equipped with isolation valves at both the front and back.
Depending on the flow of the medium on both sides of the blind flange, a shut-off valve is generally required. Since blind plates need to be removed repeatedly to open or close the flow channels, during removal, the upstream side is temporarily disconnected and the downstream side is blocked, which is achieved using double isolation valves.
Theoretically, cut-off valves should be installed at both ends, but in practice it is not necessarily required to do so. It can be determined based on the properties of the actual material! !
Not needed; some are added between the Valans, and the openings can also be removed