Civil Engineering Association

AWS C4.3/C4.3M, 4th Edition, 2018 - Recommended Practices for Oxyfuel Gas Heating Torch Operation

This manual describes the equipment, procedures, and safe practices for oxyfuel gas heating torch operation. It is written for the operators of torches using single or multiple heating tips and heads. It is also recommended for management personnel associated with the oxyfuel gas heating torch operation and process.

Oxyfuel heating is an operation whereby various metals are heated in order to perform the following operations:

(1) Straightening and bending with mechanical force

(2) Flame straightening and cambering

(3) Stress relieving

(4) Preweld and postweld heating

(5) Fusion of coatings

(6) Flame hardening

(7) Flame shrinking

The metal is heated by the direct application of single- or multi-flames to a desired elevated temperature. The heating process may be applied to all types of metal forms or shapes. An operator can make proper compensation for the effect of the metallurgical conditions, part geometry, and physical changes that may occur during the heating process.

In general, torch heating does not require any lengthy startup. Operations can be performed in most locations, in confined areas, under most conditions, and with relatively low-cost equipment. Torch heating can also be performed on completed structures without dismantling them. Although this recommended practice is not written with mandatory requirements, mandatory language, such as the use of “shall,” will be found in those portions of the document where failure to follow the instructions or procedures could produce inferior, misleading, or unsafe results.