Socket Weld Installation Gap Estimator

Per ASME B31.3 Para 311.2.2, socket weld fittings require a 1/16″ (1.6 mm) initial gap between pipe end and socket bottom before welding to allow for thermal expansion during welding and service. This tool helps verify your gap compliance and diagnose common root crack failure causes.

Nominal Pipe Size (NPS) — Select — 1/2″ 3/4″ 1″ 1-1/2″ 2″ 3″ 4″ Pipe Schedule — Select — Schedule 40 (Standard) Schedule 80 (XS) Schedule 160 XXS (Double Extra Strong) Your Measured Gap Before Welding (inches) Service Condition Standard (ambient to moderate temperature) High thermal cycling (steam, heat exchangers) Cryogenic service High vibration (compressor discharge, pump outlet) Check Compliance