What ASME Standard is used for reference?

ASME IS USED FOR WELDING EITHER INSPECTION TESTING OR CODING WELDERS

ITS AN AMERICAN STANDARD USED THROUGHOUT THE CONSTRUCTION , ENGINEERING

AND SHIPBUILDING INDUSTRY

ASME is the American Society of Mechanical Engineers. ASME codes & standards are mainly cover Boiler & Pressure Vessels' design, fabrication, inspection & testing.

Also, ASME covers material specifications for both base metals & filler metals.

Section I " Rules for Construction of Power Boilers" concerns all piping connections to power boilers or superheaters including the first stop valve on single boilers, or including the second stop valve for cross connected multiple installations.

Section II " Material Specifications" (Parts A, B, C & D) gives detailed specifications of the materials which are acceptable under this code.

Section VIII " Rules for Construction of Pressure Vessels" (Divisions 1, 2 & 3) concerns design of each vessel component.

Section IX " Welding and Brazing Qualifications" establishes the min. requirements for code welding and welding operator qualifications.

ASME covers power piping, refinery piping and liquid petroleum & gas pipelines transmission & distribution systems.

ASME B31.1 Power Piping.

ASME B31.3 Process Piping.

ASME B31.4 Liquid Transportation Systems for Hydrocarbons, Liquid Gas,

Anhydrous, Ammonia, and Alcohol's.

ASME B31.5 Refrigeration Piping.

ASME B31.8 Gas Transmission and Distribution Piping Systems.

ASME B31.9 Building Services Piping.

ASME B31.11 Slurry Transportation Piping Systems.

Also, there are a lot of codes & standards issued by ASME.

Many many other standards. http://www.asme.org/Codes/

Many many other standards: http://asme.nufu.eu/