NPT is the standard pipe thread used in the U.S. for pipe fittings. Which joint type uses this standard?

• A. Flanged
• B. Threaded
• C. Mechanical Joint
• D. Gasket Joint

Answer: (B)

NPT stands for National Pipe Thread, a tapered thread standard used to seal pipe fittings by screwing complementary male and female parts together. This threading approach is what defines a threaded joint, where the seal is achieved through the threaded engagement (often with thread sealant or Teflon tape).

Flanged joints rely on flanges bolted together with a gasket between them, not on threads for the seal. Mechanical joints use a different coupling method with clamps or wedges and typically a gasket or elastomer seal, without threaded connections. Gasket joints seal with a gasket between pipe ends and do not depend on threaded interfaces.