Top entry valve for severe industrial applications

A top entry valve for severe industrial applications, said top entry valve comprising:

• a single piece metallic body;
• a rotatable valve structure fitted within said body between valve seats also fitted into said body, said valve seats making sealing engagement with said valve structure, said valve structure having an aperture there-through for passing a fluid flow when in a predetermined open rotational position and for blocking a fluid flow when in a predetermined closed rotational position;
• said body including a top opening sized to accept entry of the valve structure and its associated seats;
• a single piece metal bonnet configured for bolted and sealed connection to the top of said body;
• and
• a rotatable valve operating stem integral with or operatively connected to the top of said valve structure so as to rotate the valve structure when the stem is rotated;
• wherein said bonnet has an aperture at its top sized to accept a sealed upper portion of said stem, and wherein:
• a sealed connection between the body and bonnet comprises a pair of spaced-apart O-rings forming a chamber there-between connected to an input port for a pressurized gas and an O-ring situated closest to the valve structure is configured to pass pressurized gas onward toward the valve structure and internal valve cavities;
• a sealed connection between an upper portion of the stem with respect to the bonnet comprises a pair of rotor seals circumferentially disposed around the rotatable stem and spaced-apart axially along the stem to form a chamber there-between connected to an input port for a pressurized gas and a chamber is configured to pass pressurized gas onward toward the valve structure and internal valve cavities.

A method of making a top entry valve for severe industrial applications, said method comprising:

• providing a single piece metal valve body having a top opening;
• providing a rotatable valve structure sized to fit through said top opening of the valve body,
• fitting said valve structure within said body through said top opening between valve seats also fitted into said body through said top opening, said valve seats making sealing engagement with said valve structure, said valve structure having an aperture there-through for passing a fluid flow when in a predetermined open rotational position and for blocking a fluid flow when in a predetermined closed rotational position;
• providing a single piece metal bonnet configured for bolted and sealed connection to the top of said body and having a top opening therein;
• fitting a rotatable valve operating stem, integral with or operatively connectable to the top of said valve structure, within rotator seals about its circumference, through the top opening of said bonnet so as to rotate the valve structure when the stem is rotated;
• and
• fastening said single piece metal bonnet to said top opening of said single piece metal valve body,
• wherein the sealed connection between the body and bonnet comprises a pair of spaced-apart seals installed on orthogonally related mated faces of the bonnet and body, wherein a chamber is formed between said pair of seals and the chamber is connected to an input port for a pressurized inert gas.