STE4 electro pneumatic control cabinet
Sempell™ STE4 is an electro-pneumatic control cabinet for control of the supplementary loading and opening of safety valves. The safety valve will be equipped with a pneumatic actuator that will be connected to the STE4. One or more valves can be connected to the cabinet. All valves will be given supplementary loading. The cabinet has 3 pressure switches connected to one sensing line each, to the system. At registration of a higher pressure than set on one of the 3 pressure switches, the supplementary loading will be switched off and a chosen valve will be given lifting air and therefore opens. The other valves work now as spring-loaded safety valves. The cabinet will switch back to supplementary loading when the pressure value is lower than set on all 3 pressure switches. The switch will be done by solenoid valves in the control cabinet.
The STE4 cabinet consists of three main components, one impulse unit with pressure switches connected to the sensing lines, one pneumatic unit handling the switch between supplementary loading and lifting air and the third unit is an electric unit. Connection to control room is possible with this unit. E.g. forced opening of the valve.
The set pressure of the valves can be checked with the STE4 control cabinet without operation of the safety valve. No interruption of the plant operation.