Carbon Steel for Instrument Air Pipe
Carbon Steel for Instrument Air Pipe
(OP)
Hi,
Is it common to have API 5L B (without galvanised) for the instrument piping material?
Based on my previous experience it should be pre-galvanised, however on my current project it is specified as API 5L B without galvanised?
Any advise
Thanks
norzul
Is it common to have API 5L B (without galvanised) for the instrument piping material?
Based on my previous experience it should be pre-galvanised, however on my current project it is specified as API 5L B without galvanised?
Any advise
Thanks
norzul





RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdo/
RE: Carbon Steel for Instrument Air Pipe
So its OK then...
Thanks
OK
RE: Carbon Steel for Instrument Air Pipe
In the long term a lot of money can be saved by having a clean air system.
= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Carbon Steel for Instrument Air Pipe
thread1036-137393
And notice rmw's statement at the bottom.
RE: Carbon Steel for Instrument Air Pipe
Not much choice but to proceed with CS. In any project, besides quality, there are 2 other factors that need to be considered i.e. schedule & cost
Hope for the best....
RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
Most places that I know of use carbon steel without galvanising. I don't know of any sites with all stainless steel instrument air piping system. Stainless steel pipes would cost a lot more. The welding would also be different I would think - although I am not familiar with stainless steel welding.
EdStainless, a quick question to you. What is the instrument air receiver/volume tank made of? If it is carbon steel, does that mean it has a liner?
RE: Carbon Steel for Instrument Air Pipe
Our company standard also doesn't really emphasize on using galvanize or SS. My previous project, as I previously mentioned, specifying galvanized CS...I can't recall why...
RE: Carbon Steel for Instrument Air Pipe
A quick question to you on the material of your instrument air receiver/volume tank. Is it also CS?
RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
I hate to through a plug in here, esp since it isn't my product. I have seen a number of plants run air line using Victaulic Press-Fit http://www.victaulic.com/docs/lit/pb-500.pdf
The last SS tube mill that I worked in ran all SS air (and all gass) lines with long runs of tubing and orbital welded joints.
= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
Thanks edstainless. Is it possible for you to indicate in what part of the world, and what specific industry, you have seen SS instr. air? If you can't, no worries.
It is just such a foreing concept (SS instr. air lines) to me, and my industry here.
I will now definitely keep my eyes open for a SS instr. air system.
RE: Carbon Steel for Instrument Air Pipe
Since then I have seen it in drug plants, breweries, and even is some manufacturing plants that have a lot of air driven equipment. They say that it significantly reduces wear and failure of air cylinders and controls.
= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Carbon Steel for Instrument Air Pipe
Thanks for the context info. I learned something new today. You get a star.
These industries you mention are completely foreign (I typed it correctly this time) to me.
I can see industries such as breweries, drugs, painting, etc. being held to a different standard wrt cleanliness - and therefore SS instr. air systems.
In oil and gas, I guess you can say we are not so fussy. In fact, we don't even always use air all the time. We often also use propane (from bullets) and process gas (the gas we are shipping is also used for instr activation) when air is not available. Where gas of any sort is unavailable, we use self contained hydraulic systems.
Thanks.
RE: Carbon Steel for Instrument Air Pipe
thread378-123404
thread378-122965
rmw
RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
Would you classify "bottled" air as "clean dry air" - the ones used in breathing apparatuses?
RE: Carbon Steel for Instrument Air Pipe
In any case I have never seen inst air used that is not dried and of course filtered. What are people thinking if they are not using dried air for sensative instruments and electronic operators.
Most instrument suppliers will also specify the type of connections and types of gases acceptable for instrument operation. If they haven't then ask them to do so such as to comply with their guarantees.
tcinc002@aol.com
RE: Carbon Steel for Instrument Air Pipe
RE: Carbon Steel for Instrument Air Pipe
As an afterthought, the design that we mostly employ for the instrumentation air is cs from the air reservoir and/or compressor to the vicinity of the instrument then SS or copper, depending on the duty, to the instrument, with of course vibration resistent mounts. We also like to use swagalock fittings (quick disconnects) and sometimes flex couplings or fittings directly on the instrument to reduce any potential leaks from vibration.
The selection of copper vs. SS depends on the duty. Mostly in petrochemical we stick with SS due to the atmospheric corrosion potential and higher pressure requirements of safety items, valve actuators. We also recommend strict compliance to maintenance for the filters, dryers, and periodic soap tests on connections. Dryers are also checked for dew point on a regular basis if not on-line moisture analyser.
tcinc002@aol.com
RE: Carbon Steel for Instrument Air Pipe
Yes, tubing from the instrument air header/piping system to the instrument is usually SS. You won't find much CS tubing.
However, the original thread was about instrument air piping, not the tubing to the instrument.