초록 ▼

A hammer union comprises a thread end, a nut end and a hammer nut which, when cinched up, compresses a composite seal assembly thereby preventing leakage. The seal assembly comprises a metal insert of a size to pass into the seal groove of conventional hammer unions and a small seal acting between t

A hammer union comprises a thread end, a nut end and a hammer nut which, when cinched up, compresses a composite seal assembly thereby preventing leakage. The seal assembly comprises a metal insert of a size to pass into the seal groove of conventional hammer unions and a small seal acting between the insert, the thread end and the nut end. The small seal is conveniently an O-ring and is of a size that is compressed when the seal assembly is inserted into the thread end of the hammer union, thereby preventing the seal assembly from falling out of the threaded end when it is inverted.

대표청구항 ▼

1. A hammer union comprisinga thread end having a conduit section providing a first flow passage, a set of coarse external threads, a first groove for receiving a seal assembly and an outwardly diverging mouth merging with the first groove,a nut end having a first terminus providing a nose having a

1. A hammer union comprisinga thread end having a conduit section providing a first flow passage, a set of coarse external threads, a first groove for receiving a seal assembly and an outwardly diverging mouth merging with the first groove,a nut end having a first terminus providing a nose having a seal seat transverse to the first flow passage and an outwardly diverging body merging with the seal seat and abutting the outwardly diverging mouth, a second terminus and a second flow passage, between the first and second termini, communicating with the first flow passage,a seal assembly comprising an annular metal insert received in the first groove and providing a second groove facing the thread end and facing the seal seat, and a resilient seal in the second groove sealably abutting the thread end and abutting the seal seat and substantially isolated by the annular metal insert from the first flow passage, anda hammer nut comprising a collar surrounding the nut end and having coarse internal threads mating with the coarse external threads thereby captivating the thread end to the nut end, drawing the outwardly diverging body into abutting relation with the outwardly diverging mouth and compressing the resilient seal and at least one ear projecting from the exterior of the collar for receiving an impact from a hammer. 2. The hammer union of claim 1 wherein the first groove is annular having a main seal receiving section of generally rectangular cross section. 3. The hammer union of claim 2 wherein the first groove provides a rim of larger diameter than the main seal receiving section. 4. The hammer union of claim 1 wherein the metal insert is loosely received in the first groove and capable of dropping out of the threaded end when the threaded end is inverted and the seal is of a sufficient size to wedge the insert in the first groove if the threaded end is inverted. 5. The hammer union of claim 4 wherein the hammer union is of a nominal 2″ diameter having a first groove of a nominal 2{fraction (11/16)} diameter, the insert having an external diameter of not more than 2.650 inches. 6. The hammer union of claim 5 wherein the second groove is of square cross-section having a first face parallel to the first flow passage and a second face perpendicular to the first flow passage, the first and second faces having a dimension of about 0.165 inches. 7. The hammer union of claim 1 wherein the seal is an O-ring. 8. The hammer union of claim 1 wherein the seal is of polygonal cross-section. 9. The hammer union of claim 1 wherein the seal is made of a material selected from the group consisting essentially of rubber, rubberoid material and mixtures thereof. 10. The hammer union of claim 1 wherein the second groove opens along an edge of the annular metal insert. 11. The hammer union of claim 1 wherein the metal insert provides a butt end, a seal end, and an outer wall of cylindrical shape generally perpendicular to the butt end providing an external diameter, the second groove opening along an edge of the insert through the seal end and through a portion of the outer wall and having a face generally parallel to the outer wall and spaced from the inner diameter, and wherein the resilient seal is an O-ring seal in the second groove extending beyond the external diameter and beyond the seal end. 12. A seal assembly for a conventional hammer union of the type having a thread end, a nut end, a hammer nut connecting the thread end and the nut end, the thread end and the nut end providing an axial flow passage therethrough and a seal cavity therebetween having a length in the direction of the flow passage, the length being variable between hammer unions, the seal cavity being bounded at one end by a non-adjustable rigid shoulder provided by the thread end and a seal seat on the nut end, comprisingan annular metal insert providing a butt end for abutting the non-adjustable shoulder, a seal end for abutting the seal seat of the nut end, an internal diameter providing a flow passage and an outer wall of cylindrical shape generally perpendicular to the butt end providing an external diameter and having a groove opening along an edge of the insert through the seal end and through a portion of the outer wall and having a face generally parallel to the outer wall and spaced from the inner diameter, the insert being sized and shaped to fit into the seal cavity and having an axial length parallel to the length of the seal cavity, the axial length of the insert being substantially less than the external diameter so the insert fits into the seal cavity; anda resilient seal in the groove extending beyond the external diameter and beyond the seal end,the metal insert substantially isolating the seal from abrasive contact with materials flowing in the flow path. 13. The seal assembly of claim 12 wherein the seal is an O-ring, the O-ring being smaller, in an unstressed condition of the O-ring, than the groove internal diameter so the O-ring may be rolled into the groove thereby tensioning the O-ring. 14. The seal assembly of claim 12 whereinthe seal assembly is for a nominal 2″ diameter hammer union and the annular metal insert has an outer diameter of not greater than 2.650 inches and not less than 2.250 inches so the metal insert will fit in an existing seal groove of nominal 2″ diameter hammer unions without machining the hammer union.