Lute to maintain Pressure/ Vacuum.

[ZeeStudnt]

Hi,

I am new to lutes. I have been searching online but not able to find much information on "Preston Lute" or "Weir/Dip pipe Lute" or any others that are more modern to the ones I have listed.

https://www.icheme.org/media/9850/xix-paper-63.pdf

This is the only one I have found but not much help on designing it.

I do have tank valves (PVRV) as primary safety on the tank but need to add redundancy in the design. Previously there was a lute fitted on the equipment I am replacing which they do like for some reason. There is no information available for it as its really old. So any help is much appreciated.
Also if there are any recomended liquids (no water) that are not on the non-REACH list.

Any ideas or nudges in the right directions are much appreciated.

Thank you in advance.

 

[LittleInch]

It doesn't take much searching to find out that these are rather old unreliable technology not suited to a new facility or reliable enough to use.

There are many other forms of PVRV available as redundancy including pallet type valves, bursting discs, duplicate PVRVs, instrumented relief valves etc

Also is this thing only going to be used for gas or liquid overflow?

A lute is going backwards in time and all the issues seem to remain so there is a good reason I can't recall seeing one in all my time hanging around storage tanks.

And they are no good in vacuum relief.

All in all it looks like a poor choice to me. All IMHO.

And don't double post.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ZeeStudnt]

Its going to be gas (vapour). Its not under much pressure/vacuum.
Burst discs are not suitable due to not being automatically resetable (if thats the correct word).
Really looking for info on Lutes and where to find - if they exist. I do understand the opinions on them that they are not very reliable compared to other tank valves (PVRV's).

 

[Latexman]

Lute ~ trap ~ P trap ~ S trap.

Good Luck,
Latexman

 

[LittleInch]

Well that paper you link to is about as good as anything I can see.

They are very simple bits of kit so not quite sure what you are asking for?

Height difference between bottom of overflow to first part of the pipe or hole in the down pipe times density of whatever liquid you want to use will give you pressure. The bigger the pit the better to avoid just blowing all the liquid out of the trap.

Hence you need to know something about volumetric flow rate / velocity in the pipe to vent. Anything more than 0.2 to 0.3 m/sec would seem too fast to me coming down the vent pipe.

There is a good reason why no one uses them nowadays....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

These are otherwise called liquid seal drums or pots and typically used in LP / LLP relief or vent or flare header service, but they arent used much these days due to concerns with corrosion or microbial growth from the seal liquid, poor reliability with seal liquid replacement after a relief event, freezing in cold weather. Another variant on this is the simple external liquid sealed gooseneck.
Vaguely recall seeing design guidelines for these in the ExxonMobil standards, and possibly in older editions of the API relating to knockout drum design (API 521 ?).