New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

Welding neck flanges are primarily used for which type of flange connection?

1. Slip-on flanges

2. Orifice plate flanges

3. Threaded flanges

4. Socket weld flanges

The correct answer is: Orifice plate flanges

Welding neck flanges are specifically designed for butt-welded connections, making them particularly useful in applications where high-pressure conditions are expected. Their gradual transition from the neck of the flange to the pipe wall helps in distributing stress and supports the integrity of the connection, which is crucial in maintaining a leak-proof seal in systems that handle fluids or gases under high pressure. Orifice plate flanges provide a means to connect orifice plates used for flow measurement and control in piping systems. While orifice plate flanges can be designed to connect to welding neck flanges, the primary application of welding neck flanges focuses on high-pressure piping connections rather than specifically on orifice plates. Their strong, robust construction and ability to endure thermal cycling and high-pressure conditions establish them as a favorable choice for crucial connections in various industrial applications. Thus, the connection involving welding neck flanges typically serves high-pressure piping, which aligns them with the types of connections that might involve orifice plate flanges but does not strictly limit their use to that application.