Can safety valves be calibrated online every year?
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I would like to ask whether safety valves can be calibrated online every year? Is there any standard that specifies this?
Safety valves cannot be removed (for example, those that are welded together); only those that cannot be calibrated offline are calibrated online.
Online calibration of safety valves has significant drawbacks: 1. It is not possible to inspect components such as the valve core and valve seat； 2. The sealing test is almost always an omitted inspection ； 3. Cannot be repaired. Which safety valves can be selected for online calibration: 1. Those with opening errors in cold and hot states that exceed the standard requirements ； 2. Safety valves that cannot be removed, such as those welded in place ； 3. Safety valve with a setting pressure greater than 10.0 MPa ；
TSG ZF001-2006 Safety Regulations for Safety Valves – Inspection and Supervision, B6.3