could I find answer for these questions
1- regard the safety valve hydrolyic test is it required to performe the test with working media (water,gas, etc).if we use air to conduct the test for reuired setting press is it quite enough, I mean is it give the same result.
2-what is optimum frquency for testing the safey valve,
1/year, 2/year etc

1. Are you an authorized test shop? If you are, then you should already have the answer to your question. If you are not, then you cannot test the PSVs yourselves if you intend to have them certified.

2. This is an on-going debate. Usually your facility will have some plan as there does not appear to be any direct requirements as far as I know. I've heard anywhere from one year to 5.