The relief valve won't really care what your case is. What is the relieving scenario? You're going to get an enormous amount of flow at 43,500 psi regardless of how big the valve is. In the past at our company, we've used the RVP series with the published areas by Autoclave, and a discharge...
Can you just vent the plastic carboy during filling? It shouldn't be pressurized at all, in which case no relief valve required. If you can't vent it to atmosphere you could just put a really low cracking pressure check valve on the thing and run the outlet line somewhere safe? Or alternatively...
AutoClave RVP series will be your friend, or a rupture disc as MortenA pointed out. We've bought these in the past:
http://www.autoclave.com/products/relief_valves/rvp_series/index.html
I feel your pain. I'm going through the same thing with AutoPIPE and just did a big vent in the piping forum! Sometimes you just have to vent somewhere...
All,
I'm just looking for some optimism. We recently upgraded to V11.1 of AutoPIPE at our company, and they have completely changed the interface/menus. It takes me forever to find anything, and you have to toggle around various menus to find commands rather than the old version with the...
ProcessRookie,
It's not too bad to do yourself, I've done it a few times since the plants our company builds are usually in the same category as yours. You can take your total inventory (2m3) and spread that out over your plant layout. Assuming no drainage, take the footprint of the area that...
Set Pressure: Nobody can answer this for you, should be on the P&ID
Built-up Back Pressure: Nobody can answer this for you, need more information. Depends on PSV size, pipe size/layout. It is the pressure drop in the piping at the relief conditions.
Superimposed Backpressure: this is the...
"The Relieving Temperature of 1556 C exceeds the Wall Temp, hence I had to specified the F' value to 0.01 and proceed on with the rest of the calculation, as per API 512 4.4.13.2.4.3."
The unwetted case may be giving you a large orifice because you've arbitrarily set the F' to 0.01, using a...
You definitely shouldn't get a similar orifice size, I wouldn't even consider the unwetted case as a valid case. Operating pressure is so much lower than the design pressure that the vessel would melt long before the set pressure is reached.
For the wetted case, I don't have Hysys so I can't...
What is the hot oil? A heat transfer oil?
If it will vaporize at the relief set pressure, then you can get your relief rate from the rate of vaporization using the equations in API 521. If it doesn't vaporize (i.e. high boiling point), the relief valve will protect against the initial expansion...
If it helps, I've almost never had a case where I've been able to reduce the outlet pipe size to below the flange size and still keep the DP at less than 10% of set pressure. Those rated flows can get you. So if someone showed me a case where the outlet pipe was smaller than the outlet flange...
Fire case is considered when there is a fire. Excess heat case is considered when there could be excess heat (steam). Size for both if they're both applicable.
Whether fire case is applicable... you haven't provided nearly enough information. Are there inventories of burny stuff nearby that...
SrChemE, yes they will react differently, but whether you ordered it for water service or you ordered it for nitrogen service, it would be the same valve. They would only change how they bench test it, and what they would stamp on the nameplate. From the Farris 2700 catalogue that Dejan linked...
Yes, the Farris 2700 can be used for both. The difference is in the discharge coefficient K used for sizing. For air/gas/steam it's 0.878, for water it's 0.676. The nameplate can only be stamped with a capacity for one service though, so yours would be stamped with a liquid capacity.
Some...
David272, have you considered relocating the relief valve to the bottom of the vessel? It could cut down on the size dramatically (liquid service but flashing in nozzle/tailpipe), and make access easier. It's quite a big decision to use an environmental factor so low, I personally wouldn't be...
If you size it for the forward pressure regulator failing open, you'd essentially be using it as a relief device at that point. Not sure if that's the main intent of the regulator, you could end up with something huge (maybe too big for a 1/4" port).
You probably have a heater somewhere in the...
There is rarely a single overpressure scenario that you could pick an orifice for. There will usually be multiple cases. Take the case a relief valve sized for a control valve or regulator failure. You usually size the relief valve for the full flow at the rated Cv of the failed device. What if...
