2006-08-14 05:18:12 · 4 answers · asked by pcjames4 2 in Science & Mathematics ➔ Engineering
The whole idea of a spectacle blind is so that one can be absolutely sure that an item of equipment is properly and securely blanked off with no possibility of any flow or leakage through a valve during maintenance. The flow can be diverted to other items of equipment but not just bypassed around the blank as this would compromise the safety function of the spectacle blind. The flow has to valved off and pressure relieved prior to loosening flange bolts and swinging the blind.
2006-08-14 05:48:09 · answer #1 · answered by Robert A 5 · 1⤊ 0⤋
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RE:
What is a spectacle blind and can you change on from open to closed in-service without stopping the flow?
2015-08-08 03:36:36 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Spectacle Blind
2016-10-31 15:09:05 · answer #3 · answered by ? 4 · 0⤊ 0⤋
It is a piece of metal that is cut to an open flange circle on one side, and a blind on the other side. These typically bolt into the pipeline at a flange connection. Usually, you would shut off the flow when you want to switch from open to closed because you have to loosen the bolts of the flange to make the change. If you want to be able to isolate the flow without having to stop the flow first, you need to install a valve.
2006-08-14 05:29:59 · answer #4 · answered by Jeffrey S 6 · 0⤊ 0⤋
A spectacle blind’ is a piping fitting that is used for providing positive isolation. It consists of a pair of metal discs attached to each other . These metal discs are cut to fit between two pipe flanges and usually sandwiched between two gaskets. One of the metal discs is solid and is used for isolating the pipe, during maintenance. The other metal disc has a circular hole to match the pipe internal diameter. The function of this disc is to allow the flow through the pipe during normal operation. Two discs are attached to each other using a metal piece with a small hole in it which can be used for rotating the spectacle blind. So during normal operation the solid disc is outside the pipe and hollow disc allows the flow through the pipe. During maintenance this blind is rotated so that the hollow disc is outside the pipe while solid disc blocks or isolates the fluid flow on one side of the pipe. I think the best thing is to stop the flow in the pipe before changing from solid disc to hollow disc in order to avoid damage to the spectacle blind and also to prevent any occurrence of hazzard.
FROM Asaolu Babatunde Anthony
2014-01-23 01:44:48 · answer #5 · answered by Babatunde 1 · 0⤊ 0⤋