What Are Tube Socket Weld Unions?

HART Industrial Unions offers a wide range of welded connection styles, including tube socket weld pipe unions. Tube socket weld unions are used as a permanent, welded connection between two tubes or tubing systems. HART Industrial Unions has the capability to manufacture standard and customized tube socket weld unions specified to any standard tubing wall thickness in both Class 3000 and Class 6000 applications.

Note that Tubing (stainless steel or otherwise) is specified by the outside diameter (O.D.) rather than the nominal size like steel piping is. For example, 1” Stainless Steel Tube is actually 1.000” O.D. and will mate with a corresponding socket weld connection on the union. HART manufactures the waterway bore to mate to standard 0.065” wall thickness tubing, but can manufacture to mate with any wall thickness you require.

HART’s tube socket weld connections are interchangeable with other HART welded and threaded connection styles and 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 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 thread
    piece 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 leak proof 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 pressure surges.
  • No Maintenance: Once the initial seal is made, no further tightening is required.

3434 Series Tube Socket Weld, Class 3000

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

  • Specifications

    Tube Socketweld Unions

  • 3D Animations
  • Datasheets
    HART 3434 Series - Technical Data Sheet.pdf HART 3434 Series - Technical Data Sheet

    HART 3434 Series – Technical Data Sheet.pdf

    HART 3434 Series - Assembly Reference

    HART 3434 Series – Assembly Reference.pdf

6464 Series Tube Socket Weld, Class 6000

HART’s Class 6000 series tube socket weld unions are suited for permanent welded connections in tubing systems that are pressure rated up to 6000 psig W.O.G.

  • Specifications

    Tube Socketweld Unions

  • 3D Animations

  • 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 tube 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.