New Mexico Pipe Fitter Journeyman (JPF) Practice Exam

How do butterfly valves compare to gate valves regarding regulation?

1. Both can be used for regulation.

2. Neither can be used for regulation.

3. Butterfly valves can regulate flow better.

4. Gate valves provide better regulation than butterfly valves.

The correct answer is: Neither can be used for regulation.

Butterfly valves and gate valves serve different functions in flow regulation within piping systems, and understanding their operational characteristics clarifies their effectiveness in this role. Butterfly valves are designed primarily for on/off control and can be used for throttling flows. However, when it comes to precise regulation of fluid flow, they are generally not as effective. The design of butterfly valves allows for quick operation and minimal pressure drop, but their disc shape can lead to turbulence and flow restriction when partially open, making precise control challenging. Gate valves, on the other hand, are specifically designed to provide either full flow or completely shut off the flow, with minimal obstructions in the pipeline. While they are not typically used for flow regulation in the same way as other valve types (like globe valves), they can be used to isolate sections of a system where control is not critical. Therefore, saying that neither can be used for regulation accurately reflects the operational capabilities of both types of valves. While both may possess some inherent ability to control flow, their designs significantly limit their effectiveness when it comes to precise regulation.