NEEDLE VALVE
A two-way valve that may be opened or closed to block the flow of fluid in a passage.
Normally manually operated, but may be automated, especially for larger sizes.
Normally designed so that the flow of fluid must make a non-straight turn inside the valve body, which results in a desired loss of pressure across the valve when open which is greater than the loss across a gate valve.
See GATE VALVE and GLOBE VALVE.
