5 replies to this topic

[eastorca]

Hello seniors,

Please, explain to me why people set up a removable spool before PSV inlet stream?
Usually, For what removable spool is used?

Thank you.

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[breizh]

Hi ,
Inspection port ?
Breizh

[eastorca]

Hi ,
Inspection port ?
Breizh

Thank you sir,

Can you explain me more?

[breizh]

Eastorca

If you remove the spool piece , you can see both side if any foriegn materials can obstruct either the drum or the PSV . My thought , others may think differently .
Breizh

[Dacs]

I think it's provision for isolation of the vessel from the line.

[kkala]

I think it's provision for isolation of the vessel from the line.

Length of this spool, at least on drawing, is same as that of one valve at the line (01-101 or 01-102), so one interpretation is that the spool has replaced a valve intended to be placed there. Concerning the PSV inlet lines there are two practices, (α) to place isolation valve (LO) or (β) not to place. Probably designers shifted from (α) to (β), when piping elements had been constructed. In the drawing there is no valve between vessel and PSV.
In that sense valve 01-105 at PSV discharge could have been removed, but it is Locked Open (LO); evidently PSV discharges to a common header, along with other PSVs.
Initially I thought the removed valve intended to isolate the vessel from its PSV during the vessel hydrostatic test. But this could be realized by a blind, as in other vessel nozzles.
However the spool may be provision for placing a valve there (LO), if needed in future. This makes another interpretation.

Edited by kkala, 06 March 2011 - 05:11 AM.