Wells 2I-Z12311

GASKT-FIBER WASHER 1/2NPT

American National Standard Pipe Thread standards, often called National Pipe Thread ("NPT") standards for short, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings. They include both tapered and straight thread series for various purposes including rigidity, pressure-tight sealing, or both. The various types are each named with a symbol and a full name; examples of the symbols include NPT, NPS, NPTF, NPSC, and others.

A washer is a thin plate (typically disk-shaped, but sometimes square) with a hole (typically in the middle) that is normally used to distribute the load of a threaded fastener, such as a bolt or nut. Other uses are as a spacer, spring (Belleville washer, wave washer), wear pad, preload indicating device, locking device, and to reduce vibration (rubber washer). Spring washers, which have axial flexibility are used to prevent fastening or loosening due to vibrations. Locking (lock) washers prevent fastening or loosening by preventing unscrewing rotation of the fastening device.