Hexagonal Fitting with Threaded Pipe Union Fitting and External Male Thread

Threaded pipe union fitting designed as a three-piece assembly — two female-threaded tail pieces joined by a centre union nut — that enables pipe disconnection and reconnection without rotating the connected pipeline. This makes threaded pipe union fittings essential wherever maintenance access, equipment removal, or system reconfiguration is required without disturbing adjacent piping. Union connections conform to ASME B1.20.1 for NPT tapered threads or BS 21 / ISO 7-1 for BSPT, and are available in ASME B16.11 socket-weld and threaded configurations. Threaded pipe union fittings are manufactured in forged or bar-stock construction, with pressure classes typically rated at 150#, 300#, and 3000# depending on size, material, and application. Common materials include ASTM A105 carbon steel, ASTM A182 F304 and F316 stainless steel, and brass (ASTM B62) for low-pressure non-ferrous service. The union seat — where the two tail pieces meet — is available in flat-face (metal-to-metal), ground-joint (cone and sphere), or O-ring seal configurations. Ground-joint unions provide angular self-alignment during make-up and are preferred for applications subject to vibration or minor misalignment. Seat faces are lapped to ensure leak-free sealing at rated pressure without supplementary sealant in ground-joint designs. Thread form is verified with calibrated ring and plug gauges to ASME B1.20.1 tolerances before release. Threaded pipe union fittings serve critical roles across fluid handling systems. Pump isolation loops use unions on suction and discharge piping to allow pump removal for impeller inspection or seal replacement without cutting pipe. Heat exchanger connections rely on union fittings to disconnect tube bundles for cleaning, re-tubing, or seasonal system changeover. Chemical dosing and sampling points use unions to swap metering pumps or install coupon holders in corrosive service lines. Steam and condensate systems employ 3000# forged unions at trap stations and strainer connections where periodic maintenance is mandatory. Compressed air distribution networks use unions at branch drops to isolate and service regulators, filters, and lubricators. ISO 9001, ISO 14001, and ISO 45001-certified facility in Yuyao, Zhejiang, with over 4,000 m² of CNC turning and Swiss machining capacity. Thread form verified with calibrated gauges before release. End markets include agricultural machinery, bearing and transmission, and compressor applications. Direct port access via our Ningbo-area plant. Specify your thread standard (NPT or BSPT), nominal pipe size, pressure class, material grade, and seat type (flat-face, ground-joint, or O-ring) to request a quotation for threaded pipe union fittings.