You need to give us definition of what about you are looking for. You could also do some research on the internet yourself.
I found:
LFE - LA(E) & LF(E) Series De-Superheating Expansion Valves
LFE - Low Fugitive Emission Valves
LFE - Laminar Flow Elements
LFE - LFE gland packing
They are valves which have low fugitive emissions. Sounds obvious, but if your contents are particularly hazardous or toxic, then any minute (fugitive) leakage is not permitted or a very low overall figure, hence if you have a lot of valves then the permitted leakage per valve can be very low. This is usually around the stem seal of what ever type of valve you have.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
lhwingking,
Okay, we now have the confirmation on the definition for the acronym LFE (special criteria for the valves) but we do not know if you want recommendations.
Did you only want the definitional or is there more?
Fugitive emission from valves are counted into the total allowed air emissions from the sites environmental permits. The air emissions from an operating plant are specified in the environmental operating permit (called a title V operating permit) that has a set maximum limit on particular chemicals such as benzene. In order to meet the title V permit conditions (in lbs per year discharged), it is necessary to use low fugitive emission valves, especially on chemical plants and oil refineries.
Dear Pennpiper, I knew the expansion. I wanted to know what it is and why it is used.
Dear Littleinch, our process engineering team says they want these LFE valves in the sour water stripper acid gas lines. Then I am thinking LFE valves are used here just to avoid H2S leakage? Because we have other toxic services where we do not use LFE valves.
Sounds like a good idea to me. Why they are not used on other toxic service I cannot comment unless the plant is quite old.
H2S is highly toxic and past a very low concentration cannot be smelt anymore, so human "detectors" are not able to be used.
Exactly how an LFE valve is different from a non LFE valve you would have to ask each vendor, but it is all about the stem seal type and packing / seals used.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
