National Certified Pipe Welding Bureau

Need Information on Welding Dissimilar Metals in Heating and AC Piping Systems?

This article presents guidance on what to do when dissimilar metals are used in heating and air conditioning piping systems. NCPWB is grateful to ASHRAE for allowing us to reproduce this article.

This document is Copyright © 2009, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Journal, Vol. 51, April 2009. This posting is by permission of ASHRAE. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission.

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NCPWB Brochure

Tools to Reduce the Cost and Risk Associated with Welding and Brazing

We invite you to browse the newest brochure from the National Certified Pipe Welding Bureau.

Why ANSI/ASME B31.9?

For quality and economy in building services piping construction, NCPWB recommends ANSI/ASME B31.9. Find out why in this Guide for Owners, Architects and Engineers. 		ASME B31.9 Brochure

NCPWB's Purpose

  • To engage in research and educational work that will assist the contractors in furnishing safe and dependable installations through the use of qualified Welding Procedure Specifications (WPSs) and qualified welders.

  • To keep contractors informed of the latest methods, information and data on welding, safety and health.

  • To establish and qualify uniform Welding Procedure Specifications (WPSs) which conform with the requirements of Section IX, ASME Boiler and Pressure Vessel Code and which comply with other nationally recognized codes for various methods of welding.

  • The NCPWB Welding Procedure Specifications are developed and qualified jointly by the members of the NCPWB and can be adopted by other members of the NCPWB under the provisions of the B31 Codes for Pressure Piping.

  • To create a force of welders uniformly trained and qualified following the uniform WPSs, thereby permitting the interchange of such welders between NCPWB members without unnecessary individual duplication of such qualification tests.

  • To assist contractors in providing the owner with quality welding at reduced costs through the use of certified welding.

  • To promote, develop the use of and generally maintain the quality of welding in the piping industry.

What Is Certified
Pipe Welding?

Certified Pipe Welders at Work



Membership Requirements

  • Be a mechanical contractor who is regularly engaged in the fabrication or erection of piping systems.
  • Must be signatory to a labor agreement with the United Association of Journeymen & Apprentices of the Plumbing & Pipefitting Industry (United Association or UA for short).
  • Be a member of a local chapter of the NCPWB where available before joining the national organization.

For more information, contact NCPWB's Executive Director Nick Nikpourfard.


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