I want to know what is the allowable limit of oil in Inst Air for Process Control.

 

We have data about Instrument Air Quality :
1. ISA 7.0.01 mentioned that Air Instrument should be free oil, at least max oil content is 1 ppm.
2. However, in our plant, its difficult to acheive standard until free oil, but oil content as 1 ppm, also too dangerous. Therefore, we follow ISO 8573-1 Class 1 that Aerosol oil content is lower or same as 0.01 mg/m3.

 

No oil or water please. Nice dry air eliminates a lot of problems.

regards

 

This is quite easy. Refer to ANSI/ISA–7.0.01–1996, "Quality Standard for
Instrument Air"

"5.3 Lubricant content
The lubricant content should be as close to zero as possible, and under no circumstances shall it
exceed one (1) ppm w/w or v/v. Any lubricant in the compressed air system shall be evaluated
for compatibility with end-use pneumatic devices. For example, the use of automatic oilers is
strongly discouraged."