7 replies to this topic

[avsp]

Hi,

Currently, I am working on a LPG Cavern Storage project, in which the client is looking into the possibilities of installing a particular Relief valve with a flow alarm / switch connection, integral with the valve body.

Actually, for this particular relief valve, the client wanted that whenever there was an occurence of this relief valve relieving, there should be an alarm in the control room. At the same time, he is not comfortable with the idea of having the flow switch installed in the discharge pipe of the relief valve. I have asked around in my company and also searched the net but all this was of no help.

Can anybody help me in locating relief valve vendors, who are in a position to supply such relief valves?

I shall be grateful to anyone for any help in this regard.

Cheers ,

[gvdlans]

avsp,

I cannot give you a direct answer to your question (I never heard of a relief valve with an integrated flow switch), but would like to give some comments.

I was involved in design and engineering of a propane storage cavern a few years ago. Here we also had some relief valves with a flow switch (pitot tube) in the discharge line. Can you explain why your client is not happy with this?

In my case the flow switches not just generated an alarm but also had a shutdown function (e.g. close valves in cavern fill line or trip cavern propane pumps).

[avsp]

gvdlans,

The current design of this LPG Project, by the concerned process licensor, talks of the same kind of arrangement i.e. pitot tube flow switch, which you had described in your reply. However, the client basically would like to keep his relief valve discharge piping as simple as possible sans any kind of valves, fittings etc. (Nevertheless, I did try advising the client that a pitot type flowmeter as a flow instrument does not introduce any kind of major fittings, except one small pitot tube extending into the pipe and introduces minimal pressure drop in the line). He was just exploring the possibilites of an alternative solution to this. Probably, if this kind of an arrangement is not available in the market, he may go with what is being originally suggested i.e. pitot tube arrangement.

Thank you very much for your quick response.

Cheers ,

[gvdlans]

I just checked the legends of the P&IDs of the cavern project and saw that we had a "target type sensor", and not a pitot tube as I originally wrote. A pitot tube would work as well I would say. An example of such a target type sensor can be found on http://www.deltacnt.com/624.htm

[avsp]

gvdlans,

Thank you very much for this useful piece of information.

I am not very sure whether the client is amenable to this kind of an istrument but nevertheless, I am going to communicate with the client, right away, with this information. Honestly, I have never come across this type of a flow instrument and this information is going to be useful for me in the future as well.

Just one more thing I would be interested in is a rough cost estimate for this instrument and an approximate delivery schedule (considering the fact that this particular LPG Cavern project is in India).

Thanking you in anticipation,

Cheers ,