Monolithic Isolation Joints

Product Features:

  • Weld-in style monolithic isolation joint, factory manufactured and tested, no field assembly required
  • Double o-ring seal standard (triple available for severe service)
  • Internal and External Coated
  • Available from ½” Diameter to over 120” Diameter
  • Available in ANSI 150, 300, 600, 900, 1500, 2500, 5000 / API 10,000
  • Available in a variety of forged steel grades and materials
  • Manufactured under ISO 9001:2008 & PED Certification
  • Available for subsea applications
  • Available with no internal welds for critical service
  • 2” Thru 16”, Class 150 / 300 / 600 typically in stock for immediate deliveries

The use of a weld-in style monolithic isolation joint eliminates the “jig-saw-puzzle” installation of gasket isolation kits and allows for a tested and ready-to-install, finished product. The ALFA monolithic isolation joint interrupts the flow of electrical current along the pipe, utilizing dielectric materials encapsulated in the joint design. The ALFA joint exhibits high dielectric and physical strength for a long term, robust and reliable solution.


Pipeline isolation is used to electrically “split-up” pipelines into distinctive segments. This isolation of pipelines is essential to ensure that cathodic protection (impressed current) is applied and controlled, to prevent “long line” currents and to make the individual cathodic protection systems more effective and economic. Isolation also facilitates prevention of stray electric currents, decreasing corrosion. Isolation of pipelines can provide protection against earthing currents. Isolation of the pipeline can also be used where dissimilar metals are found together to help prevent the galvanic action between the metals. Importantly, isolation can also be used at custody transfer points in pipelines to ensure that two different pipelines, and their corrosion systems do not adversely affect one another.


Monolithic isolation joints are a long-term, reliable, robust and cost-effective solution for pipeline isolation. ALFA Monolithic Isolation Joints are assembled and tested in a clean factory setting. This allows for easy installation (weld into place). The advantage to monolithic joints is multi-faceted including but not limited to:

  1. Decreased project and life cycle costs
    • Decreased installation time and labor over gasket isolation kits
    • No maintenance after proper installation
    • Eliminates field assembly and related time and labor attributable to improper assembly of gasket isolation kits
    • No pipeline shutdown caused by failure, replacement or leakage of improper assembly of gasket isolation kits
  2. Increases safety of pipeline and life duration of isolation joints in comparison to gasket isolation kits.

ALFA Engineering operates a Quality Assurance System and is registered ISO 9001:2008. ALFA Engineering is PED Certified.

During manufacturing every joint undergoes meticulous and thorough testing. These tests include hydrostatic testing, hydro fatigue testing, dielectric testing, electric insulation testing, coating testing, weld testing, and more. Tests can be defined by user, and witnessed by third party if required. ALFA monolithic isolation joints can be provided with all testing data and material test reports (MTRs) upon request.

Contact Us to Learn How Alfa Monolithic Isolation Joints Can Protect You.

Exceptional Isolation. Robust, Reliable Solution.