Chemical flow restriction orifice plate

At present, the application of flow limiting orifice plates in domestic process equipment is still insufficient, and there is a gap compared to foreign countries. When it is necessary to limit flow or reduce pressure, regulating circuits are mostly used to achieve this. In some places, the flow rate of the fluid is only required to be limited within a certain specified range without adjustment, and the accuracy of its flow rate is not high. A limiting orifice plate can be used instead. Therefore, it is necessary to fully recognize the advantages of flow limiting orifice plates in the design of process equipment, attach importance to the application of flow limiting orifice plates, and have various forms of flow limiting orifice plate application performance. The flow restriction orifice plate is designed and manufactured according to national standards such as GB2624, HG/T 20570, GD2000, GD87, etc.

Basic principle of multi-stage flow restriction orifice device

The purpose of measuring flow rate can be achieved by measuring the pressure drop before and after the fluid flows through the throttling device. This measurement method is based on Bernoulli's law and the law of continuity of fluid flow. The basic principle of the flow restriction orifice plate is the same as that of the throttling device. Due to their different roles and usage conditions, there are also differences in the methods and calculation accuracy considered.

Firstly, the flow restriction orifice plate is not a measuring instrument and requires low accuracy, so certain influencing factors can be ignored. Such as the influence of temperature on pipe diameter and opening diameter, and the influence of Reynolds number on flow coefficient.

The limiting orifice plate only serves to reduce pressure and limit current. The pressure drop on the orifice plate refers to pressure loss. The pressure drop on the restriction orifice plate is much greater than that on the throttling device. That is to say, under the same flow conditions, the range of aperture ratio β can be extended to 0.05-0.75.

Application of Multi level Flow Limiting Orifice Device

The main function of the flow restriction orifice plate is to limit the flow rate and reduce pressure, so it can be used in the following situations:

1. occasions for reducing pressure of process materials

When the process material flows from the high-pressure area to the low-pressure area, the flow restriction orifice plate can play a role in controlling the pressure drop. By installing a flow restriction orifice plate, the material pressure can be gradually reduced to meet the operating pressure requirements. The flow limiting orifice plate is relatively simple, reliable, and cost-effective, making it more advantageous than some complex pressure reducing devices in such situations.

2. Valve protection occasions

When a large pressure drop is required upstream and downstream of the valve in the pipeline, the erosion of the valve by the fluid will be more severe. If throttling through orifice plates does not produce gas phase, connecting orifice plates in series upstream of the valve can effectively reduce the impact of fluid on the valve.

3. Small flow continuous circulation occasions

(1) Pump flushing pipeline: In chemical plants, some mechanical seals and other parts of pumps require continuous flushing liquid to prevent medium leakage and seal damage. The flow restriction orifice plate can ensure a stable supply of flushing liquid at a small flow rate. After installing the flow restriction orifice plate, an appropriate amount of flushing liquid can be provided, which not only ensures the cooling and flushing effect of the seal, but also does not have adverse effects on the operation of the pump.

(2) Bypass pipeline of hot standby pump: In a system with a standby pump, a certain bypass flow rate is required to keep the standby pump in a hot standby state. The flow restriction orifice plate can control the bypass flow rate, ensuring that the standby pump can be put into use at any time.

(3) Analysis sampling tube: When analyzing the composition of process fluids, a small and continuous sample flow is required for the analysis sampling tube. The flow restriction orifice plate can precisely control the sample flow rate.

4. Pressure reduction, noise reduction or wear reduction occasions

In the venting system, a sudden decrease in pressure may generate significant noise. By installing a flow restriction orifice plate, the fluid pressure can be gradually reduced, which can effectively reduce noise and wear.