What is the difference between a limited flow orifice plate and a regular orifice plate flow meter?

Project Overview

There are significant differences between the restriction orifice plate and the ordinary orifice plate flowmeter in many aspects. The following is a detailed explanation of these differences:

1. Measurement principle:

• Orifice plate flowmeter: It is a differential pressure flowmeter. By placing an orifice plate upstream of the pipeline, the fluid flows through the orifice plate to generate a differential pressure signal, and then the flow rate is calculated based on the differential pressure. It works by relying on the local contraction of the fluid near the throttle, the increase in flow velocity, and the static pressure difference generated on its upstream and downstream sides.

  

• Flow-restricting orifice plate: By reducing the cross-sectional area of ​​the pipe and increasing the fluid velocity, flow measurement is achieved. When there is a certain pressure difference before and after the orifice plate and the fluid flows through the orifice plate, for a certain orifice diameter, the flow rate flowing through the orifice plate increases as the pressure difference increases. But when the pressure difference exceeds a certain value (called the critical pressure difference), the flow rate of the fluid through the shrinkage hole of the orifice plate reaches the speed of sound. At this time, no matter how the pressure difference increases, as long as the pressure upstream of the orifice plate remains constant, the fluid flowing through the hole will The flow rate of the plate will be maintained at a certain value and will not increase.

• Scope of application:

• Orifice plate flowmeter: suitable for flow measurement of stable fluids and single-phase liquid or gas media with low viscosity. It is widely used in process control and measurement in petroleum, chemical industry, metallurgy, electric power, heating, water supply and other fields.

• Flow-restricting orifice plate: suitable for fluids containing solid particles, liquids, gas mixtures and high-viscosity liquids with high fibrils, viscosity, particles and corrosiveness. Flow measurement. In addition, it can also be used where the flow rate needs to be limited or the pressure needs to be reduced, and where the fluid needs a small flow rate and continuous flow.

  

• Structural features:

• Orifice plate flowmeter: a high range-to-range ratio consisting of a standard orifice plate and a multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter and pressure transmitter) The pressure flow device has the characteristics of simple structure, convenient maintenance and stable performance.

• Flow-limiting orifice plate: It has the advantages of simple structure, easy processing, low manufacturing cost, and convenient installation. it can rootDesigned and manufactured according to national standards GB2624, HG/T 20570, GD2000, GD87 and other standards, and can be divided into single-hole plates and multi-hole plates according to the number of holes on the orifice plate, and can be divided into single-stage and multi-stage according to the number of orifice plates.

  

• Function application:

• Orifice flow meter: mainly used to measure fluid flow and widely used in various industrial fields.

• Flow-restricting orifice plate: It can not only be used as a flow measurement component to measure flow, but also can be used as a throttling component to limit flow and reduce pressure. In some places, the flow rate of the fluid is only required to be limited to a certain specified range without adjustment, and when the accuracy of the flow rate is not high, a flow-limiting orifice plate can be used instead.