Pressure balanced bellows seal

A bellows seal assembly for containing process fluid under pressure in a valve comprising:

• a first bellows assembly;
• a second bellows assembly substantially concentric with said first bellows assembly;
• means sealably interconnecting said first bellows assembly and said second bellows assembly in an end-to-end arrangement and preventing a telescoping relationship therebetween;
• a substantially incompressible pressure balancing fluid received within and contacting an inner periphery of said first and second bellows assemblies
• said process fluid contacting an outer periphery of said first and second bellows assemblies;
• said first bellows assembly sealably attached to actuating means;
• said second bellows assembly sealably attached to housing means;
• and
• whereby displacement of said actuating means causes displacement of said first and second bellows assemblies while maintaining a pressure balance between said incompressible pressure balancing fluid and said process fluid.

A bellows seal assembly comprising:

• a first bellows assembly;
• a second bellows assembly substantially concentric with said first bellows assembly;
• means sealably interconnecting said first bellows assembly and said second bellows assembly in an end-to-end arrangement and preventing a telescoping relationship therebetween;
• a housing substantially surrounding said first bellows assembly and said second bellows assembly;
• a substantially incompressible pressure balancing fluid received within said housing;
• said process fluid contacting an inner periphery of said first and second bellows assemblies;
• said first bellows assembly sealably attached to actuating means;
• said second bellows assembly sealably attached to said housing;
• and
• whereby displacement of said actuating means causes displacement of said first and second bellows assemblies while maintaining a pressure balance between said incompressible pressure balancing fluid and a process fluid.