Method of using a bonnet and stuffing box assembly

A method of manufacturing a bonnet and stuffing box assembly comprising:

• casting a bonnet and a stuffing box from a corrosion-resistant material, the bonnet defining a substantially conical bonnet bore portion and the stuffing box defining a substantially conical stuffing box bore portion, the substantially conical bonnet bore portion and the substantially conical stuffing box bore portion together defining an assembly bore;
• precision-machining a stuffing box bushing bore wall of a stuffing box bushing;
• precision-machining a bonnet bushing bore wall of a bonnet bushing, the bonnet bushing and stuffing box bushing together defining a bushing assembly, the bonnet bushing bore wall and the stuffing box bushing bore wall together defining a bushing bore;
• and
• positioning the bushing assembly within the assembly bore;
• and
• securing the stuffing box to the bonnet with a fastener to retain the bushing assembly within the assembly bore;
• wherein:
• securing the stuffing box to the bonnet with the fastener comprises tightening the fastener to press a stem flange of a stem down upon the bushing assembly to seat the bushing assembly in the assembly bore;
• precision-machining the stuffing box bushing bore wall comprises precision-machining a first annular indentation in the stuffing box bushing bore wall;
• precision-machining the bonnet bushing bore wall comprises precision-machining a second annular indentation in the bonnet bushing bore wall;
• the first annular indentation and the second annular indentation together define an annular flange channel;
• and
• the stem flange engages the annular flange channel.

A method of using a bonnet and stuffing box assembly comprising:

• providing a stuffing box, a bonnet, a bushing assembly, and a stem, the stuffing box and the bonnet defining an assembly bore, the bushing assembly received in the assembly bore, the bushing assembly defining a bushing bore, and the stem received through the bushing bore;
• sealing the stem relative to the bushing assembly to prohibit fluid flow through the bushing bore;
• sealing the bushing assembly relative to the bonnet to prohibit fluid flow through the assembly bore;
• and
• turning the stem relative to the bushing assembly, bonnet, and stuffing box to actuate a valve;
• wherein:
• the bushing assembly comprises a bonnet bushing disposed at least partially within the bonnet and a stuffing box bushing disposed at least partially within the stuffing box;
• at least a portion of the stuffing box bushing extends beyond a top end of the bonnet;
• the stuffing box bushing defines a stuffing box bushing bore wall;
• the bonnet bushing defines a bonnet bushing bore wall;
• the bonnet bushing bore wall and the stuffing box bushing bore wall together defines the bushing bore;
• an outer bonnet bushing surface of the bonnet bushing defines a circumferential bonnet bushing groove;
• a packing received in the bonnet bushing groove;
• and
• sealing the bushing assembly relative to the bonnet comprises engaging the packing with a bonnet bore wall of the bonnet.

A method of using a bonnet and stuffing box assembly comprising:

• providing a stuffing box, a bonnet, a bushing assembly, and a stem, the stuffing box and the bonnet defining an assembly bore, the bushing assembly received in the assembly bore, the bushing assembly defining a bushing bore, and the stem received through the bushing bore;
• sealing the stem relative to the bushing assembly to prohibit fluid flow through the bushing bore;
• sealing the bushing assembly relative to the bonnet to prohibit fluid flow through the assembly bore;
• and
• turning the stem relative to the bushing assembly, bonnet, and stuffing box to actuate a valve;
• wherein:
• the bushing assembly comprises a bonnet bushing disposed at least partially within the bonnet and a stuffing box bushing disposed at least partially within the stuffing box;
• at least a portion of the stuffing box bushing extends beyond a top end of the bonnet;
• the stuffing box bushing defines a stuffing box bushing bore wall;
• the bonnet bushing defines a bonnet bushing bore wall;
• the bonnet bushing bore wall and the stuffing box bushing bore wall together defines the bushing bore;
• the stem defines a stem groove;
• a packing received in the stem groove;
• and
• sealing the stem relative to the bushing assembly comprises engaging the packing with one of the stuffing box bushing bore wall and the bonnet bushing bore wall.