NPT (National Pipe Thread) ring gages are essential tools for inspecting the quality of threaded pipe fittings. Each type serves a specific purpose in the inspection process. Let's break down the differences between L1 Basic, L2 Basic, and 6-Step Crest Check NPT ring gages:
L1 Basic Ring Gage:
- Purpose: Primarily checks the minor diameter of the thread at the hand-tight length of engagement (L1).
- Focus: Ensures the thread is within tolerance for proper mating and sealing.
L2 Basic Ring Gage:
- Purpose: Checks the taper and overall thread profile at the wrench-tight length of engagement (L2).
- Focus: Verifies that the thread has the correct taper and extends to the required length.
6-Step Crest Check Ring Gage:
- Purpose: Inspects the truncation limits and taper of the major diameter.
- Focus: Assesses the sharpness of the thread crests and the consistency of the taper.
- The small end of the ring gage is required to be flush with the small end of the pipe within a tolerance of plus or minus one turn.
- Click HERE for Pitch Diameter Chart
