This specification covers underwater welding in both dry and wet environments. Operations required at the surface related to and in support of underwater welding are within the scope of this document, but welding above the surface is not. All provisions of this document apply equally to new construction and to modification and repair of existing structures underwater.1.2 References
It shall be the responsibility of the Customer to specify the appropriate editions of the standards referenced in this specification. The following documents are incorporated by reference:
ASTM E 426, Practice for Electromagnetic (Eddy-Current) Examination of Seamless and Welded Tubular Products Austenitic Stainless Steel and Similar Alloys
This specification addresses fabrication and quality standards for underwater welding. This document may be used in conjunction with other applicable codes or speci- fications for design, construction, or repair.
1.4.1 All references to the need for approval shall be interpreted to mean approval by a duly designated person acting for and in behalf of the Customer on all matters within the scope of this specification. The Customer may designate an engineer, inspector or other(s) to act in the Customer’s behalf to assure that the requirements of this specification are fulfilled. The Customer should specify the authority of the authorized representatives. Hereinafter, the term Customer shall be used to mean the party contracting for the work or the authorized representative.
1.4.2 In this specification, the term "shall" indicates a mandatory requirement and has the significance of excluding the idea of discretion. The word "should" indicates a nonmandatory recommended practice. The word "may" implies no obligation and expresses liberty or permission.
1.4.3 For Class O welds (see 2.1.7 and 5.6), conflicts between referenced documents and this document shall be brought to the attention of the Customer for disposition. In general, the referenced documents may take precedence in matters not affected by the underwater environment. However, this document shall take precedence in matters related to the underwater welding environment and working conditions.
1.5 Base Metals
1.5.1 The base metals presently included under this specification are carbon, low alloy, and austenitic stainless steels commonly used in the fabrication of steel structures. The weldability of the steel and the procedures for welding it shall be established by qualification. Each procedure is qualified based on the carbon content, carbon equivalent, and strength of the base metal to be welded in production. Production welding on base metal of carbon equivalent or strength above that qualified shall require requalification of the procedure. (Carbon equivalent shall not applicable to austenitic stainless steel base metals.)
1.5.2 This specification may be used for welding of other base metals. In such cases, applicability of specific requirements shall be determined by the Customer.
1.6 Welding Process
1.6.1 Gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), flux cored arc welding (FCAW), plasma arc welding (PAW), and shielded metal arc welding (SMAW) are the principal joining processes addressed by this specification. These processes may be used, provided the welding procedure is qualified in accordance with all applicable requirements of this document.
1.6.2 Other welding processes may be used at the discretion of the Customer, provided the applicable qualification requirements of this specification are met.
The welding terms used in this specification shall be interpreted in accordance with the definitions given in the latest edition of ANSI/AWS A3.0, Standard Welding Terms and Definitions, supplemented by Annex B of this document (AWS D3.6M).
1.8 Welding and NDE Symbols
Welding and examination symbols shall be those shown in ANSI/AWS A2.4, Standard Symbols for Welding, Brazing, and Nondestructive Examination. Special conditions shall be fully explained by added notes or details.
1.9 Safety and Health
This document is not a safety standard and does not establish specific performance requirements for safety issues or procedures associated with diving or underwater welding. However, Annex D provides some guidance relative to safety in underwater welding and cutting. Additional pertinent welding safety information can be found in the documents referenced in Annex E . In addition, manufacturer's safety literature on equipment and materials, as well as other pertinent documents, should be considered. Each contractor must determine independently whether the safety precautions contained in the referenced publications are adequate.
1.10 Standard Units of Measure
The values stated in SI units are to be regarded as the standard. United States Customary Units, shown parenthetically, may be approximate and are for information.