„Inching“ is defined as: „required to occasionally drive the valve to a position between fully open and fully closed. “
Class C (modulating) increases the demands on: „required to frequently drive the valve….”
|Notes for the table can be found in the draft standard:
To a) : One cycle consists of nominal 90o angular travel in both directions ( i.e 90o to open and 90o to close), based on an averaged load of at least 30 % of the rated torque with the ability to transmit 100 % of the rated torque for at least 5 % at each end of travel, For angular travel other than 90o the endurance shall beagreed between the purchase and the manufacturer/supplier
To b) : One start consists of a movement of at least 1o in either direction, with a load of at least 30 % of the rated torque.
Additional requirements: The actuator must be able to exert at least 90% of its original torque at the end of the test. The travel must likewise be between 98% and 102% of its original travel at the end of the test.