Hydro Test of Nitrogen Cylinders

[ak1965]

What should be the frequency of hydrotesting of pressurized Industrial Nitrogen Cylinders?

I feel that once it is hydrotested at supplier's shop, should not require a retest untill some problem is evident.

Any comments please...?

 

[metengr]

ak1965;
Check with your local Jurisdiction that regulates pressure vessels. In some applications, like pressurized fire extinguishers they are small pressure vessels, and are hydrotested once every 3 or 5 years.

If these vessels are not regulated in lieu of hydrostatic testing, a visual inspection should be performed with at least UT of wall thickness to ensure safe operation once every 3 to 5 years. I would not wait until a problem develops.