Classification opinions
… … 2. Pneumatic actuator valve, for regulating the flow of various liquids and gases, in which the position of the plug … A stem gasket, of plastics; (iv) A stem, of plastics; (v) A housing, of plastics; (vi) A steel spring; (vii) A diptube, … the valve opens, thereby allowing the flow of air into or out of the tyre, depending upon the pressure differential. …