The externally controlled straight way valve is pneumatically operated. It consists of a diaphragm actuator and a 2-way valve body. Between the valve body and the actuator, there is a hermetically sealed diaphragm. The diaphragm actuator moves a spindle with valve disc against a spring and switches the valve. The spindle is designed glandless with a double seal. The actuator housing is made out of epoxy resin.