So is the stress in a formed head direction-dependent? Or can it be assumed to be Omni-directional? In a shell, it makes sense to orient an elliptical manway with the shortest diameter in the longitudinal direction (since that places the smallest area normal to the circumferential stress). If...
Hey all,
I am trying to determine which diameter to use in reinforcement calculations for a 12"x16" manway that is inserted into an ellipsoidal head. I know on the shell there is the F factor to take into account the difference between longitudinal and circumferential stresses, but I am not...
@bimr
The concern at the present time is that the designers of the system might have incorrectly designed it so that components are in danger of failure if a regulator fails.
@LittleInch
I know that the 104 is meaningless, but in API 520 terms, its what the relief valve could be set at to...
@bimr
This system has been in use for 10+ years and is a gaseous nitrogen.
@LittleInch
Okay this is all making sense now, but I have one question:
This specific situation has 2 panels. The second panel has no relief valve but is entirely fed by the first panel that has a relief valve d/s of...
@Latexman
The orifice in question has an opening of 0.025" and is definitely smaller than the regulator.
@LittleInch
I am looking at a bunch of nitrogen panels and there are orifices right before a lot of the pressure gauges (which I do not understand) of different pressure ranges. These...
But wont the orifice within the regulator result in a drop in pressure across the regulator even when it fails?
And I know what scfm means, I just do not understand what an orifice rated for 8.1 scfm entails. Flow changes with u/s pressure and incoming flow, so how is it rated for a certain...
Howdy!
I am trying to understand the fluid mechanics theory to understand a problem I am trying to solve.
Say I have a system that has 2640 psig inlet pressure. This flow goes through a regulator and then through an orifice which leads to a pressure gauge that has a range of -30-0-30 psig.
If...
Well, without going into too much detail, I am writing a report that will urge the facility to install a new relief valve. The regulator in question was manufactured in the 60's, so its probably been refurbed a few times. Regardless, ~1800 scfm will take the system to over three times its MOP...
The Cv of the regulator is 0.6.
EDIT: The Cv calculator you provided, when solving the air/gas equation for Q using the Cv for the regulator results in a flow of 703 CFM. Using another Cv equation that I have found from Swagelok and Sandia National Laboratory results in a Q of 731 SCFM...
I can see how both of your viewpoints stem from varying things I have said. I will attempt to start from the beginning but add updated info:
I am trying to determine if the relief valve d/s of a regulator will be able to maintain 120% system MOP if the regulator were to fail.
u/s of the...
Alright, follow up question time. Are manufacturer flow charts applicable for a state of failure for a regulator? Or are they only applicable assuming normal operating conditions? Using Cv equations from literature produce flow rates that greatly differ from manufacturer flow charts.
Thanks again!
I work with a safety office and am definitely aware of the possible ramifications, which is why I want to be perfectly sure that my methods and line of thinking are correct. Thanks to everyone who provided input and helped, it is greatly appreciated.
TD2K, the 230 scfm at 200 psig was from a Capacity Chart for an incorrect relief valve. The RV im looking at does not have any capacity charts for air/gas because it was intended for liquid service. That alone means it will get replaced.
However, due to the lack of a proper capacity chart for...
The upstream volume is massive compared to the downstream. The system layout is as follows:
~1200 cubic feet of compressed helium in the form of four 300 cubic foot tanks runs through a manifold that has its own relief valves, check valves, etc. It then exits the manifold and penetrates a...
