HART Carbon Steel Socketweld Unions connected to a valve.

HART carbon steel socketweld connected to a valve.

HART Industrial Unions offers a wide range of welded connection styles, including socket weld pipe unions. Socket weld unions are used as a permanent, welded connection between two pipes or piping systems. HART can manufacture standard and customized socket weld unions specified to S10, S40, S80, S160, and XXH welding schedules in Class 3000 and Class 6000 applications.

Socketweld Unions come with ASME B16.11 and B36.10M female socket connections where a stainless or steel pipe can be inserted and welded for a rigid, secure connection.

HART’s socket weld connections are interchangeable with other HART welded and threaded connection styles. They can be manufactured in a variety of materials, including but not limited to carbon steel 12L14 or A105, stainless steel 304 or 316, Monel 400, Hastelloy, and Aluminum. HART also offers tube-style socket weld unions (3434 series) for welding tubes instead of pipes.

HART O-Ring Union Features:

  • Turbulence Free: All unions provide a turbulence-free fit across the seats
  • O-Ring Isolation: The O-Ring seal is strategically located in the threadpiece face, eliminating O-Ring media contact and added protection against abrasives and erosion. A variety of O-Rings for any application are available.
  • Precision Machined Components: All unions are precision machined to provide high quality and fail-safe leakproof reliability.
  • Interchangeable End Connections: HART’s male threaded connections feature interchangeable configurations with other threaded or welded connections, reducing the need for nipples or additional fittings.
  • Material Versatility: Unions can be provided in all standard metals or combinations of metals. This includes 304 Stainless, 316 Stainless, A105 Carbon Steel, Brass, Monel 400, Hastelloy, and Titanium.
  • Excellent Vibration Resistance: Seals will not loosen, even under extreme pressure and surges.
  • No Maintenance: Once the initial seal is made, no further tightening is required.

3333 Series Socket Weld Pipe, Class 3000

Class 3000 Series socket weld unions are ideal for permanent welded connections in piping systems that are pressure rated up to 3000 psig W.O.G.

  • Specifications
    SizeA-NPSBC-HEXDE-TAILF-THREADWEIGHT (LBS)
    3333-11/4"1.761.380.750.80.960.33
    3333-23/8"2.011.821.130.941.070.7
    3333-31/2"2.011.821.130.941.070.7
    3333-43/4"2.162.151.381.031.131
    3333-51"2.62.51.751.251.351.75
    3333-61-1/4"2.773.062.161.381.392.5
    3333-71-1/2"3.113.382.381.531.583.5
    3333-82"3.283.882.881.551.734.25
    3333-92-1/2"4.015.003.611.992.026
    3333-103"4.285.754.302.142.148

  • 3D Animations
  • Datasheets
    HART 3333 Series - Technical Data Sheet.pdf HART 3333 Series - Technical Data Sheet

    HART 3333 Series – Technical Data Sheet.pdf

    HART 3333 Series - Assembly Reference

    HART 3333 Series – Assembly Reference.pdf

6363 Series Socket Weld Pipe, Class 6000

HART Industrial Unions Class 6000 series socket weld unions are suited for permanent welded connections in piping systems that are pressure rated up to 6000 psig W.O.G.

  • Specifications
    SizeA-NPSBC-HEXDE-TAILF-THREADWEIGHT (LBS)
    6363-11/4"2.011.821.130.941.070.7
    6363-23/8"2.011.821.130.941.070.7
    6363-31/2"2.162.151.381.031.131
    6363-43/4"2.62.51.751.251.351.75
    6363-51"2.773.062.161.381.392.5
    6363-61-1/4"3.113.382.381.531.583.5
    6363-71-1/2"3.283.882.881.551.734.25
    6363-82"4.015.003.611.992.026
    6363-92-1/2"4.285.754.302.142.148

  • 3D Animations
  • Datasheets

  • Piping systems, especially those that need to meet tight regulatory requirements or specifications
  • Plumbing systems with weldable components
  • Highly sensitive processing and transportation applications that cannot permit any risk of a potential leak, typically involving flammable, expensive, or toxic fluids

HART Industrial Unions’ Capabilities

At HART Industrial Unions, we design and construct high-pressure and specialty unions for a wide variety of piping and tubing system applications. We build our socketweld unions to last with superior resistance to vibration, turbulence, and erosion. HART constructs unions from a vast selection of metals and fitting options to create the perfect fit, including stainless and carbon steel, aluminum, Hastelloy, and Monel 400.

We make our precision-machined components in the USA, including our comprehensive line of Sure Seal O-rings. Found on the face of a thread piece, these O-rings reduce media contact in joints and ensure a reliable, fail-safe seal for your systems.

To learn more about our Engineering and Manufacturing Capabilities, visit our Capabilities.

Contact us today to learn more about our selection of socketweld unions or to request a quote.