Patent ID: 8359743

Claim:
In a sealant fitting (A) comprising a sealant body ( 100 ), a vent cap ( 200 ), and a ball seat ( 120 ), the sealant body having a cap coupling screw part ( 101 ) disposed on an outer upper end of the sealant body, a valve coupling taper screw part ( 101 - 1 ) disposed on an outer lower end of the sealant body, a sealant injection hole ( 102 ) disposed on an inner upper end and a ball installation groove ( 103 ) disposed on an inner lower end, the ball installation groove ( 103 ) having a ball ( 110 ) while the ball seat ( 120 ) and a coil spring ( 130 ) being sequentially disposed downward from the ball installation groove, the vent cap having a protrusion ( 210 ) for discharging an inner air and additionally blocking the sealant injection hole ( 102 ) and one or more punched vent grooves ( 220 ), the vent cap being coupled to the cap coupling screw part ( 101 ) of the sealant body ( 100 ), the vent cap ( 200 ) having a coupling groove ( 230 ) with a constant diameter inside the vent cap, an internal screw thread ( 240 ) formed on an inner wall of the coupling groove ( 230 ), the protrusion ( 210 ) protruded from an inner central position of the coupling groove, one or more vent grooves ( 220 ) punched on an upper end of the vent cap, and a marking part ( 250 ) formed on an upper surface of the vent cap, the ball seat ( 120 ) having an inner groove ( 121 ), a lower spring sustaining protrusion ( 122 ), and a groove ( 123 ) for tight contact with the ball and fluid communication, a method of manufacturing the vent cap ( 200 ) and the ball seat ( 120 ), comprising the steps of: selecting one or more metal powder materials S meeting a certain mechanical property and mixing the one or more metal powder materials together; injecting the one or more metal powder materials S into a separate mold die ( 50 ) with an inner pin ( 40 ) having a certain shape and being fixed in the die, and pressing the metal powder materials by means of a mold-pressing device ( 10 ) composed of an upper punch ( 20 ) and a lower punch ( 30 ) processed according to shapes of the ball seat ( 120 ) and the vent cap ( 200 ) of interest to be molded to mold the materials into a predetermined shape; sintering the predetermined shape of the materials at a temperature that is substantially high, constant, and adjusted to a degree not greater than a melting point so that the pressed metal particles have a sufficient metallic bonding property; and performing post-processing by carrying out surface heat treatment required for a portion or an entire part of the sintered alloy mold and removing a bur or a sharp edge that may be present on the surface by means of brushing.