Heat treatment apparatus and valve device for use in the same

A heat treatment apparatus having a reduced pressure exhaust valve with an automatic remote control device and an emergency shut-off device, said reduced pressure exhaust valve comprising:

• a valve body to be rested on a valve seat in a valve closing direction and to be lifted from the valve seat in a valve opening direction by sliding of a valve rod in gas tight manner through a valve casing,
• an urging means for urging said valve body in the valve closing direction,
• an electric drive means for opening/closing said valve body through said valve rod against an urging force of the urging means, and
• interconnection releasing means disposed between the electric drive means and said valve rod for bringing said valve rod and the electric drive means into interconnection with each other, and for releasing the interconnection in an emergency to close said valve body, the interconnection releasing means includes lock pin holes formed both in the electric drive means and the valve rod, a lock pin to be engaged into said lock pin holes, a single acting hydraulic cylinder driving the lock pin, and a control means for deenergizing the single acting hydraulic cylinder in an emergency, the interconnection releasing means disengaging the lock pin out of the lock pin hole.

A heat treatment apparatus having a reduced pressure exhaust valve with an automatic remote control device and an emergency shut-off device, said reduced pressure exhaust valve comprising:

• a valve body to be rested on a valve seat in a valve closing direction and to be lifted from the valve seat in a valve opening direction by sliding of a valve rod in gas tight manner through a valve casing,
• an urging means for urging said valve body in the valve closing direction,
• an electric drive means for opening/closing said valve body through said valve rod against an urging force of the urging means, and
• interconnection releasing means disposed between the electric drive means and said valve rod for bringing said valve rod and the electric drive means into interconnection with each other, and for releasing the interconnection in an emergency to close said valve body, the interconnection releasing means includes an attracting unit disposed on the electric drive means;
• wherein the attracting unit attracting an end of the valve rod by an electromagnet generated thereby, and being deenergized in an emergency to release the end of the valve rod.