This document specifies quality levels for imperfections in joints in thermoplastic moulded components due to the joining process.

This document does not describe imperfections that can be generated either during service or present before joining, such as poor fit up. The correct preparation before joining is described in the relevant thermal joining process specification (TJPS), as defined in ISO 23512.

Three quality levels are specified in order to permit application for a wide range of the following joining processes:

a) ultrasonic welding;

b) ultrasonic spot welding;

c) infrared welding;

d) hot gas convection welding;

e) vibration welding;

f) spin welding;

g) laser welding;

h) hot plate welding; and

i) heat staking: hot air; electrical, infrared and ultrasonic.

They are designated by symbols B, C and D, where B is the most stringent. The quality levels refer to production quality and not to the fitness for purpose of the manufactured product.

NOTE      Standards on joining of plastic pipes, fittings, valves and/or auxiliary equipment, and the assessment of the properties of the resulting joints are developed and maintained by ISO/TC 138.