ASME B31.3

Overview

ASME B31.3 is the leading international code for process piping systems used in industries such as oil & gas, chemical, pharmaceutical, and power plants. It defines requirements for design, materials, fabrication, assembly, inspection, and testing of piping systems.

Standard: ASME B31.3

Industry: Process & Industrial Piping

Scope: Design to Testing

Applications: Refineries, chemical plants

Key Features

Comprehensive piping design and engineering code
Covers materials, fabrication, and inspection
Defines fluid service categories
Specifies NDT and testing requirements
Widely used in process industries worldwide

Fluid Service Classification

Fluid Service	Category	NDE Requirements	Typical Applications
Normal Fluid Service	D	5% RT/UT of welds	Water, air, steam
Category D Service	D	Visual inspection	Low pressure non-hazardous
High Pressure Service	M	100% RT/UT	High pressure systems
Severe Cyclic	Special	Enhanced NDE	Compressor discharge lines

Design Considerations

Pressure and temperature limits
Pipe stress analysis and flexibility
Thermal expansion and load handling
Support and anchoring systems

Fabrication & Inspection

Qualified welding procedures (WPS/PQR)
Welder qualification (WPQ)
Non-destructive testing (RT, UT, PT, MT)
Hydrostatic and pneumatic testing

Applications

Oil & gas refineries
Chemical and petrochemical plants
Pharmaceutical industries
Power and utility systems
Cryogenic and high-pressure piping systems