What is the orifice plate used for?
Table of Contents
What is the orifice plate used for?
An orifice plate is a device used for measuring flow rate, for reducing pressure or for restricting flow (in the latter two cases it is often called a restriction plate ).
What is an orifice and how does it work?
Basic Working Principle of an Orifice Meter The liquid or gas whose flow rate is to be determined is passed through the orifice plate. This creates a pressure drop across the orifice plate which varies with the flow rate, resulting in a differential pressure between the outlet and inlet segments.
How does an orifice plate reduce flow?
Restriction orifices reduce the flow rate by introducing an additional pressure drop in the pipe. It works in a manner similar to a partially closed gate valve.
Why are orifice plates beveled?
The purpose of having a square edge on the hole in an orifice plate is to minimize contact with the fast-moving moving fluid stream going through the hole. Ideally, this edge will be knife-sharp. Beveled orifice plates are obviously uni-directional, and must be installed with the paddle text facing upstream.
How do you identify an orifice in the pipeline?
An orifice tab is welded on the orifice plate which extends outer of the line giving an indication of the orifice plate.
Does an orifice reduce flow?
A reduction in orifice size results in decreased flow as only so much liquid can pass through the orifice. Since the flow of liquid is limited by the orifice, it follows that the pressure on the exit side of the orifice is less than that on the inlet side.
Why orifice plate is tapered?
The hole is “tapered”, meaning that the edge of the orifice hole is sharp. The plate must be inserted in such a way as to have the direction of flow of gas from the smaller to larger diameter, i.e. if the gas is flowing from left to right, the sharp edge of the orifice (the smaller diameter) must be at the left.
How do I identify an orifice?
An orifice plate is primarily a thin metal plate with a hole bored in the center. It has a tab on one side where the specifications such as Tag number, orifice bore diameter (in inches), the material of orifice plate (ex: SS316) are stamped. The stamping is made on the plate upstream side of the flow direction.
Where is orifice meter used?
The orifice plate flow meter is commonly used in clean liquid, gas, and steam services. It is available for all pipe sizes but it is very cost-effective for measuring flows in larger ones (over 6″ diameter). The orifice plate is also approved by many organizations for custody transfer of liquids and gases.