A closed valve has to be filled with water under pressure and must be completely enveloped in flames with an environmental temperature in the region of the valve of 750- 1,000°C for a period of 30 minutes.
The objective is to completely envelop the valve in flames to assure that the seat and sealing areas are exposed to the high burn temperature.
The intensity of the heat input is monitored using thermocouples and calorimeter cubes as specified in the standard.
During this period the internal and external leakage is recorded. After a (forced) cooling down, the valve is hydrostatically tested to assess the pressure containing capability of the valve shell, seats and seals.
If all results are within the prescribed parameters, the valve will be considered as ‘fire safe’ and receives a test report with a certificate. As an independent leak testing company, ITIS often sees misinterpretations regarding valves and fire safe testing.