Patent ID: 8056418

Claim:
Method for monitoring the functionality of an actuator for a safety valve, said actuator includes a pneumatic drive and a magnetic valve for controlling said pneumatic drive, comprising the steps of: monitoring said first pneumatic conduit by measuring pressure in said first pneumatic conduit, said first pneumatic conduit interconnecting a position controller of said actuator and said magnetic valve, a second pneumatic conduit interconnecting said magnetic valve and said pneumatic drive; switching said magnetic valve from a first state to a second state at time t 1 , said first state of said magnetic valve interconnecting said first pneumatic conduit and said second conduit enabling communication therebetween, said second state of said magnetic valve venting said magnetic valve, said first and said second pneumatic conduits; switching said magnetic valve from said second state to said first state at time t 2 ; and, when the switching time of said magnetic valve, t 2 -t 1 , is small, said actuator and said safety valve do not substantially change position.