As a throttling element, flow limiting orifice plates have the advantages of simple structure, easy processing, low manufacturing cost, and convenient installation. Under the premise of meeting the process requirements, using flow limiting orifice plates instead of regulating valves to limit flow or reduce pressure will greatly reduce investment and operation and maintenance costs. Therefore, they have been widely used in process devices abroad, playing an important role in the safe operation of the device.

Principle of flow limiting orifice plate:
Restriction orifice plate is used to limit the flow rate of fluid or reduce the pressure of fluid. The fluid passing through the orifice plate will generate a pressure drop, and the flow rate passing through the orifice plate will increase with the increase of pressure drop. But when the pressure drop exceeds a certain value, that is, beyond the critical pressure drop, regardless of how the outlet pressure decreases, the flow rate will maintain a certain value without increasing. The flow limiting orifice is used to limit the flow rate or reduce the pressure of the fluid based on this principle.


Classification of flow limiting orifice plates:
The flow limiting orifice plate is divided into single orifice plate and porous plate according to the number of openings on the orifice plate; According to the number of orifice plates, it can be divided into single level and multi-level.

Material of flow limiting orifice plate:

Standard materials include 316 stainless steel, 304 stainless steel, 310 stainless steel, Hastelloy C276, Hastelloy B3, duplex stainless steel, super duplex stainless steel, Monel 400, carbon steel, titanium, nickel 600, tantalum, PTFE, and PVDF. Other special materials can be customized.


Function of flow limiting orifice plate:

1. Places where process materials need to be depressurized;

2. When there is a need for a significant pressure drop upstream and downstream of the valve in the pipeline, in order to reduce fluid erosion on the valve, orifice plates can be connected in series upstream of the valve when there is no gas phase generated through throttling through the orifice plate;

3. Places where fluid requires low flow and continuous flow, such as the flushing pipeline of the pump, the bypass pipeline of the hot standby pump (low flow protection pipeline), and the analysis sampling pipeline;

4. Places that require depressurization to reduce noise or wear, such as vent systems.