Spectacle blind in PSV inlet line
Spectacle blind in PSV inlet line
(OP)
Can someone help to find a reference regarding spectacle blind in PSV inlet lines?
In general, I don't like to have a spectacle blind in a PSV line from a pressure vessel. For maintenance purposes, the nozzles on the vessel shall be equipped with spectacle blinds. However, for PSV lines I would like to have a removable spool installed as this reduce the risk to have the PSV line blocked during start-up (as the blind can be left in close position.
So, does it exist a reference to a API standard or similar regarding this topic?
In general, I don't like to have a spectacle blind in a PSV line from a pressure vessel. For maintenance purposes, the nozzles on the vessel shall be equipped with spectacle blinds. However, for PSV lines I would like to have a removable spool installed as this reduce the risk to have the PSV line blocked during start-up (as the blind can be left in close position.
So, does it exist a reference to a API standard or similar regarding this topic?





RE: Spectacle blind in PSV inlet line
The only time I've had to provide spectacle blinds on PSV inlet when we installed a new pair of PSVs routed to a flare header in addition to the original pair routed to atmosphere. The ones routed to flare were added because of an ongoing issue with the PSVs to atmosphere lifting when the compressors tripped and relieving the process to atmosphere on a regular basis wasn't acceptable to the client. The PSVs routed to atmosphere were left because during regeneration, the process was full of air and you couldn't relieve that to the flare. As a result of this, the client's environmental group deemed the atmospheric PSVs during normal operation became a fugitive emission point and as we only had a single block valve on the inlet, we had to install the spectacle blnds (due to access, that was preferable due to installing another inlet block valve).
RE: Spectacle blind in PSV inlet line
RE: Spectacle blind in PSV inlet line
Thanks for your response
RE: Spectacle blind in PSV inlet line
Spectacle blinds have fallen out of favor in some companies due to problems with leakage.
RE: Spectacle blind in PSV inlet line
RE: Spectacle blind in PSV inlet line