Welding Procedures

Matt Stennett, P.E.Vice President – EngineeringMiddle Tennessee Natural Gas

mstennett@mtng.com

Mass Confusion

• Qualifying a PROCEDURE vs qualifying a WELDER

• 192.225 Welding procedures.• (a) Welding must be performed by a qualified welder or welding operator in accordance with welding procedures qualified under section 5, section 12, Appendix A or Appendix B of API Std 1104 (incorporated by reference, see §192.7), or section IX of the ASME Boiler and Pressure Vessel Code (ASME BPVC) (incorporated by reference, see §192.7) to produce welds meeting the requirements of this subpart. The quality of the test welds used to qualify welding procedures must be determined by destructive testing in accordance with the applicable welding standard(s).

• (b) Each welding procedure must be recorded in detail, including the results of the qualifying tests. This record must be retained and followed whenever the procedure is used.

Welder Welding Procedure

Procedure:  How You Weld

• We use World Testing, Inc. in Mt. Juliet, TN for our destructive testing• Our welder makes a weld on a pipe however he wants

• World Testing doesn’t care HOW it’s done

• All of the welder’s settings and techniques are recorded by a Certified Welding Inspector

• The weld is destructively tested to prove that THIS PARTICULAR METHOD of welding works

Pipe Coupon Prep

Tensile Test

Bend Test

Nick Break Test

Why Qualify A New Procedure?

• PROCEDURE QUALIFICATIONS• It shall be the responsibility of Middle Tennessee Natural Gas Utility District to qualify welding

procedures and to maintain records of such qualification. When materials, applications, conditions, or any other factors change requiring new welding procedure(s) to be developed, it shall be the responsibility of Middle Tennessee Natural Gas Utility District to create and qualify the new procedure(s). Welding procedures to be used for pipeline welding shall generally be qualified as specified in the edition of API Standard 1104 which is referenced in DOT 192 at the time of qualification. Other standards may be used to qualify procedures for pipeline welding only if they are in accordance with the latest edition approved by the DOT.

MTNGUD O&M Manual Excerpt

Matt Stennett, P.E.Vice President – EngineeringMiddle Tennessee Natural Gas

mstennett@mtng.com