30 replies to this topic

[Dilu]

Thanx Fallah .... Can you have any sizing sheet for rupture disc (fire case). And what would be the relief temperature in this case ?

[fallah]

Thanx Fallah .... Can you have any sizing sheet for rupture disc (fire case). And what would be the relief temperature in this case ?

 

Dilu,

 

I haven't a sizing sheet at the moment, but i did explain for sizing in the post No. 11 and for relieving temperature in the post No. 14 of this thread. Start the sizing and if you would have any question/clarification let's know to answer...

[Dilu]

Thanx ... I waz actually confused as relief temperature waz 206 at ibp while design was 72. Oka I wil consider 206 C as releiving temperature is it ok ..?

[fallah]

Dilu,

 

If it is "initial bubble point corresponding to relieving pressure", no problem...

 

One more thing; be careful, you are using standard relief valve sizing formula and RD inlet/outlet lines lengths shall be very short and the outlet shall be discharged directly to atmosphere...

[Dilu]

Thanx Fallah .... Done..

[staffel]

Dilu,
as suggested by Fallah if you have a vessel containing liquid
the bubble point temperature is a correct criteria but you
need liquid composition which changes according vessel's pressure and temperature
(ok, no problems for pure fluids)
and you need to iterate (you know the discharging pressure,
not the discharging temperature) untill you'll find correct values,
this is a quite tedious procedure and a more simple and direct solution
(solving a flash at specified volume and pressure)
has been described in my previous post #16,
by the way you may wish to compare as the predicted temperatures may differ,
also consider that is only the initial step and the conditions
inside the vessel , I mean P and T (as the properties of discharged fluid)
will change depending from external fire and conditions and
composition of fluid in vessel.

Edited by staffel, 28 November 2013 - 06:16 AM.