4 replies to this topic

[afi]

Dear Engineers;

I want to know your opinion in selecting the instrument air quality based on ISO 8573.1 for free oil and dust instrument air (which one has best quality and also most cost effective).

Thanks so much

[Zauberberg]

In all the plant where I have been working so far, the Instrument Air quality was as per the Class 3 requirements. Depending on climate conditions you may need to go for Class 2 or even Class 1 (for lower dew points).

So, the question is not so much in what is the cost-effective solution but rather in what are the minimum site requirements. Filtering of oil and particles is easy to achieve in a relatively small pieces of equipment, air drying can be done with PSA Alumina beds (for dew points down to -40 or -50 degC), or with TSA Mol Sieve beds for dew points below -50 degC.

[afi]

In all the plant where I have been working so far, the Instrument Air quality was as per the Class 3 requirements. Depending on climate conditions you may need to go for Class 2 or even Class 1 (for lower dew points).

So, the question is not so much in what is the cost-effective solution but rather in what are the minimum site requirements. Filtering of oil and particles is easy to achieve in a relatively small pieces of equipment, air drying can be done with PSA Alumina beds (for dew points down to -40 or -50 degC), or with TSA Mol Sieve beds for dew points below -50 degC.

Dear Zauberberg;
Thanks a lot for your answer; therefore if I got correctly, you mean it doesn’t matter to select each class of oil and particle (except dew point)beac
I want to know when we say OIL FREE AND DUST FREE instrument air which class of ISO is at least required.

thanks again

[Zauberberg]

Afi,

No one can answer that question except you - and that is because you are the person who should know what compressed air application you are referring to: is it a process plant? is it a chemical laboratory? or medical institution? in tropical Africa? or in the Arctic Sea?

[ankur2061]

Dear Zauberberg;
Thanks a lot for your answer; therefore if I got correctly, you mean it doesn't matter to select each class of oil and particle (except dew point)beac
I want to know when we say OIL FREE AND DUST FREE instrument air which class of ISO is at least required.

thanks again

Afi,

Have a look at this link:

http://www.coleparme...lter.htm&ID=701

This should guide you for selection of the air quality required by you.

Regards,
Ankur.