seal material for argon flow

Argon is an inert gas. http://www.coleparmer.com/techinfo/chemcomp.asp

Hi vscid,

You can use any seal for argon gas.

of course, any seals can be used. but you should choose the best seal for it. Any is a dump advice.

I disagree, 'Any' is quite reasonable advice given the lack of information in the original question. vscid is now able to make a decision based on the other parameters of his valve; as Beej50 says, Viton would suit high temperatures. EPDM would suit low temps and Buna N would do if cost was a major factor.

Drew

In general, "any" is quite reasonable advice given the lack of information, but in specific cases, it must be clear.

Please give us more clearly informations such as Liquid or gas Argon, temperature, pressure, flow.

But I think the best seal for argon is rubber in normal condition.

Find clear informations below, man!

You only need to consider Viton for high temperature. Argon is fairly cold!

You only need to consider Viton for high temperature. Argon is fairly cold!

That makes no sense. The seals can be whatever temperature your parts are working in or as hot as the heat balance (heat created +/- heat transfer in or out) makes it. If you valve cycles often and/or is energized for a long time (high duty cycle) and is thermally isolated you might have a significant increase in internal operating temperature over ambient air temperature, therefore the Argon gas inside could get quite hot requiring Viton seals! Also, he says nothing about what the Argon is used for, so the temperature of the Argon flowing through the valve is totally unknown! It could be hot or cold.

My answer at #4 was based on the fact that I have never heard of hot argon and if it was the fluid in an operating valve, presumably it would have some pressure drop and therefore be cooling!

You will note that I didn't give a recommendation as to the type of seal to use!

The question as posed only warranted a 'one liner' and, with that, we cannot cover all bazaar conditions!

According to a fluid compatibility guide that I have from Aro, Buna N and Neoprene are listed as " not recommended"

Acetal, EPR, EDPM, Low and High Density Polyethylene,Polyurethane, Urathane, Teflon, and Viton are listed as "recommended, performance is not affected"

Hope this helps.

Both are compatible for argon. Viton has higher heat rating.

wow! this one's stirred quite a debate!

well, I am using this argon as a shielding gas in robotic TIG welding, so I belive its not in liquid form.The gas will probably flow at about 30 cfh.

Also,atleast one of the compatibility tables tell me that argon is compatible with Buna N.

However,1 valve manufacturer told me that argon was not compatible with its valve seals (Buna-N) , whereas another one told me that it was. (Interestingly, both the valves are similiar is most aspects).

Hence, I am confused.

If the information is different from two vendors that want to sell you something, get an opinion from someone that has no profit to gain from the product you buy.

As I see it, based on the information provided by others above, it appears that your two manufacturers have different design priorities.

Since the compatibility is worded merely as "Not recommended", and not something stronger like "Incompatible", or "Not allowable", it seems that one of the manufacturers is more concerned with reliablity and safety than cost, while the other is content to accept a certain amount of risk in order to keep costs low.

You have to make the same decision in your application, risk (and consequences of failure) versus initial purchase cost. Many engineers and manufacturers would say that such a decision, if significant, might warrant completing a FMEA (Failure Mode and Effects Analysis) and, based on that, make your decision. Of course an FMEA is just a more formal way of doing what engineers do every day based on experience and knowledge. You may be able to reason through the process informally and come to your own decision. Assuming there is a cost difference, you can decide to go with the manufacturer who decides it is better to err on the side of caution by absorbing a little extra cost, or to select the manufacturer who feels that risk is minimal and produces a design that will have a lower cost and work fine in the majority of applications. If the two items are price competitive then the decision is a no brainer, go with the one with the upgraded seals.

A wise old engineer once told me early in my career, not unlike something you might find in a fortune cookie, "The sweet taste of initial lower cost and satisfactory performance often turns into a bitter aftertaste when the REAL long-term costs of selecting the cheaper product are measured."

The complete wording in the compatibility chart was " Not Recommended, Material Is Unsuitable For Service" The cost between Buna "N" and Viton should be less than 1% of the cost of the solenoid.