Double seal thermostat

摘要

A choke type thermostat is provided with dual choke seals including a conventional primary choke and a secondary choke which seals with the valve seat of the thermostat prior to the sealing of the primary choke. The secondary choke provides additional sealing for the valve and also functions to strain the flow of coolant which is allowed to pass over the primary choke, thereby preventing sand or other debris from interfering with the sealing of the primary choke.