This is covered in API 520 Part 2 section 8. The norm is to provide block valves that are full bore but the actual verbiage in the code is that the flow area of the isolation valves has to be at least equivalent to the relief device inlet and outlet connection area and definitely greater than...
To take credit for these secure air supplies you will need to have a very robust inspection & maintenance regime to ensure they are holding tight. The volume bottles may also need to be fitted with an alarm and dual class 1 check valves to ensure a robust secure design.
My plant's vent and...
Hello
I am hoping someone may have some advice on an issue I'm having with rating a control valve in supercritical gas Service. The gas is High pressure, low temperature hydrocarbon gas at 105.5 bar(g) and -15 degC. Molecular weight is in the range 20 - 22 kg/kmol. The valve is an emergency...
Thanks for your post PaoloPemi. Your mention of Masoneilan prompted me to check their sizing handbook and they are explicit in their note that the "rho1" is at flowing fluid temperature. Therefore the SG is simply the flowing fluid density at upstream conditions divided by water at 15 degC
Thanks
Hi all.
Hoping someone can help me with the following query:
ANSI/ISA-75.01.01 equations for incompressible fluids make use of the fluid relative density. The symbol used in the equations is "rho1/rho0" and in section 5 it defines "rho1" as the density of the fluid at P1 and T1. Therefore, is...
Thanks very much for the responses, much appreciated.
@mk3223 - Operations did not check the flange break tags on the downstream joints - they assumed they were all torqued and that a single valve isolation was adequate just to get the upstream system up to test pressure. They did not envisage...
Hi
It is not impossible - you have the information that you require.
You have defined the required flow rate and the upstream pressure and therefore you can either assume a downstream pressure to calculate the orifice size for the flow you require to pass or else assume an orifice size to...
Hello
I apologise in advance for any ignorance here as I am not a mechanical engineer.
I am wondering if there are any industry standards or recognised best practice documents available for flange break management? I will try and articulate the specifics of what I am looking for below...
We...
Hi George - there is no suction scrubber per-se on this system...the upstream "scrubber" is a demethaniser column. Dry sales spec gas from the top of the demethaniser is boosted via recompressors driven by turbo-expanders and warmed through the gas-gas exchangers. This upstream system is...
Sorry George but I'm not permitted to share the P&ID due to company information disclosure guidelines.
Machine is a 2 stage centrifugal compressor with a single "long recycle" line (i.e. 1 recycle valve for both compressors via the coolers) and a "hot gas bypass"/quick recycle.
The suction...
@LittleInch - Thanks for the detailed response. I feel that we are on the same page & agree that there are other options worth looking at. Hydrotesting this section of plant is the last thing I want to do. Thanks for the prompt regarding the weight - will have our Civil/Sturctural Engineer...
@georgeverghese - yes suction pipework design pressure can be exceeded in certain cases as identified by the HAZOP i.e. max mol wt case with MOP at the suction side and max feasible head across the machine. This has not happened in the past but it is feasible and credible.
@EdStainless - we...
Don't forget to consider the entire operating envelope of the pipeline e.g. if the fluid is retrograde - at higher export rates & lower landed pressures at the LPG plant more liquids will drop out in the pipeline.
You can use the Cunliffe method to get a simple feel for slugcatcher size...
Hi all.
I have run a quick search on the forum be couldn't find anything that covered this topic so hence the question.
Caveat...I'm a process engineer rather than mechanical so I apologize in advance for any ignorance below.
The question is...Is it safe to complete a hydrotest on an...
Hello
I am currently assessing hydrocarbon pool fire formation from leak sources in an NGL/LPG service. My company has an internal quick reference flow chart to decide whether or not hydrocarbons released in the form of an aerosol jet could rain out and form a pool of liquids at grade. This...
