Vacuum valve with heater

A vacuum valve with a heater, the vacuum valve comprising:

• a valve casing including a first main port, a second main port, a flow path connecting both the main ports, and an annular valve seat provided in the flow path;
• a cylinder connected to the valve casing;
• a poppet-type valve member provided in the valve casing to open and close the valve seat;
• a hollow rod having a tip end portion connected to the valve member and a base end portion extending into the cylinder;
• a piston disposed for sliding in the cylinder and connected to the base end portion of the rod to be driven by an action of fluid pressure;
• one or more first heaters and temperature sensors mounted to the valve member;
• a terminal block mounted to the piston to be displaced with the piston;
• a connector mounted to an end portion of the cylinder;
• a beater primary conductor and a sensor primary conductor respectively extending from the first heater and the temperature sensor, passing through the rod, and having tip ends connected to the terminal block;
• a heater secondary conductor and a sensor secondary conductor having one ends respectively connected to the heater primary conductor and the sensor primary conductor through the terminal block, having the other ends connected to the connector, and having a spiral portion for expansion and contraction at an intermediate portion.