That would probably work, as long as you have enough vapor space in the system. Most liquids do not expand very much with temperature, but the pressure rise can be tremendous due to thermal expansion if the fluid is blocked in (in other words, the liquid has a fixed volume). Many people use a...
Assuming the fluid is a liquid, the pressure rise will be tremendous. You should have a pressure relief system if there is any way the pipe could be blocked off.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
Thanks, Jack. I have looked at the ASHRAE handbooks and found them to be very valuable. The 3E software came out with a value that was within the expected range for an outdoor ammonia storage tank, so I feel good about the calculations.
Tony Miller
Cornerstone Engineering Group, p.c...
Thank you very much for your reply. I used the 3E heat transfer software and I think that will do very nicely.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
I need to calculate the heat flux into a large, outdoor vessel, which is about 60 feet diameter and 40 feet tall, with a domed roof. I have all the dimensions and insulation details. The insulation is styrofoam with a reflective metal jacket. The vessel is about -20 F inside.
My question is...
Yes, that is advice well given and well taken. This particular vessel has a vent line that is always open to atmosphere.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
Thanks for all of the comments. I do have software to calculate the rating, but I discovered that there are no credible scenarios for creating a vacuum. It is an ammonia plant, so all vessels are normally under pressure (not vacuum) but the existing PSV also had vacuum protection.
I guess the...
Thanks for the responses. It is an old vessel and unforunately there is no vacuum rating.
I am at home now, and do not have the vessel's details. . .
I guess I'll recommend some kind of device that will prevent a vacuum.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
Is this a very large pipeline? Normally thermal relief requirements are very small.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
Go here:
http://digitalsolutions.org/Single_Phase.doc
There is a table on page 17.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
I am working on a relief system for a Section VIII vessel rated at 60 psi MAWP. I am familiar with overpressure protection, but I am wondering about vacuum protection on this vessel.
If a scenario exists that could produce a vacuum, do I need to provide a vent for that? The U1 report for the...
Thank you for your reply. I have done many thermal expansion relief scenarios, and the flow for liquid thermal expansion has always been very small compared to a fire case boiling scenario. Nevertheless, I will check into it. The calculation is easy enough, as you said.
I'm calculating the relief valve requirement of a fire case for a water-filled jacket on a vessel. I'm planning to calculate the heat from the fire, calculate the vapor generation, and then convert it to the same volume of liquid (at relief pressure) since liquid will be pushed out the relief...
I can assist you, but I do not think I can do it through this forum. Pressure relief valve sizing is just too complex. Contact me through the URL below if you would like some assistance.
Someone please let me know if this post is inappropriate.
Tony Miller
Cornerstone Engineering Group...
I understand that recoverable losses (such as due to velocity change in an enlarger) are NOT considered in pressure drop calculations for the inlet piping for a relief valve (API RP 520).
Does the same apply to the exit piping? Sometimes considerable enlargements in the outlet piping take...
Wow, you folk are amazing. Thanks for the help.
hacksaw, the conditions are 170 F and 175 psig. Cp looks like about .205 BTU/lb-f.
Molecular Weight 100.016
Atm Boiling Pt, F -105.3
Freezing Point, F -224.5
Critical Temperature, F 91.9
Critical Pressure...
I have heat capacity at constant pressure, Cp (but not Cv), critical compressibility, critical pressure, temperature, volume, and some other physical properties of the gas. The gas is tetrafluoroethylene, otherwise known as TFE or R1114.
Does anyone know of a way to estimate or calculate the...
Do you know if the referenced method uses the homogeneous flow theory approach? I have found a good discussion of that approach. Also, I am familiar with it because of my work with pressure relief valves.
Thank you for your responses.