Acf Industries, Incorporated

Hamid J Saka

Danny S Meyer

Anthony A Laitkep

Scott W Binegar

A fire-safe valve structure for a valve of the type having a valve body with a flow passage (18, 20) therethrough and a valve chamber which houses a valve element (70) for opening and closing the flow passage, the valve chamber becoming sealed off from the flow passage in the open and closed conditions. An annular metallic seat (110) with a port (200), which extends between its inner and outer annular surfaces (186, 188) and so located as to communicate the valve chamber with the flow passage, is disposed in an annular seat pocket (28) formed around the flow passage (20) on the upstream side of the valve. The seat pocket (28) opens to the valve chamber (50) and the metallic seat (110) is provided with sealing means (196) for sealing with the valve element (70) in the open or closed condition. A relief plug (202) of a selected temperature degradable material is positioned within the port (200) so that when the chamber is sealed off and the plug (202 ) is exposed to the environment within the valve chamber (50), the plug (202) will evacuate the port (200) at the degradation temperature of the plug material or will be ejected from the port (200) at a preselected pressure differential between the valve chamber (50) and flow passage (20), whichever first occurs. The pressure build-up in the valve chamber (50) which results from rising temperature is then relieved by communication of the chamber through the port (200) to the upstream flow passage (20).

Fire-safe valve structure

A 'fire-safe' packing arrangement (104) for a valve stem (72) which extends through a packing chamber in a valve bonnet bore (42) to a valve chamber (50) in a valve body (12). The packing arrangement (104) comprises a low temperature packing assembly (112)positioned within the packing chamber between the stem (72) and the wall of the bonnet bore (42) for sealing therebetween at normal temperatures and resting on an inner annular shoulder (62) provided in the bonnet bore (42). A metal spacer ring (116) is positioned within the packing chamber axially outward of the low temperature packing assembly (112) with respect to the flow passage (18, 20) through the valve. The spacer ring (116) has a lower side or inner end (140) thereof resting on the low temperature packing assembly (112). The packing arrangement includes a high temperature packing assembly (114) positioned within the packing chamber between the stem (72) and the wall of the bonnet bore ( 42) and axially outward of the spacer ring (116) with respect to the flow passage (18, 20). The high temperature packing assembly (114) is sandwiched between the outer end portion (138) of the spacer ring (116) and a retainer (106) seated on an annular shoulder (58) provided in the bonnet bore (42). The high temperature packing seals between the stem (72) and the valve body (12) at above normal temperature conditions of the valve body (12) which are destructive of the low temperature packing assembly (112). The packing arrangement (104) effectively seals throughout the range of low and above normal temperatures without imposing frictional drag on the valve stem.

Valve stem packing structure

A gate valve having a gate assembly of the expanding type employing a gate element (34) and segment (36) with adjacent wedge surfaces to expand the gate mechanism in both open and closed positons. Opposed floating seat skirts (68) having integral seat assemblies (52, 54) are positioned on opposite sides of the expanding gate valve and have facing slots (76) therein to receive spacer plates (82) therein which maintain a predetermined spacing between the skirts to minimize any binding of the skirts against the gate assembly and to provide a predetermined minimum clearance between the skirts at all times.

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Houston, TX, United States of America

Hamid J Saka