Pressure relay: From Principle to Application, Comprehensive Analysis

In the field of industrial automation, pressure relays, as an important automatic control device, play a key role in automatically opening and closing circuits according to pressure conditions.

This article will introduce in detail the definition, working principle and application cases of pressure relays in various fields, giving you a comprehensive understanding of this important industrial component.

First, the basic concept of Pressure Relay
A pressure relay is a device that uses pressure changes to control the on and off of a circuit.
It can automatically determine whether the pressure reaches the critical value based on the set pressure value, thereby triggering the switch action to connect or disconnect the circuit.
This automatic control method effectively avoids damage to the equipment due to too high or too low pressure, while reducing production costs and maintenance costs.

Secondly, the application fields of pressure relays
1.Petroleum and chemical industry: In the petroleum and chemical production process, pressure relays can monitor pressure changes in containers and pipelines and trigger alarm devices or automatic regulating valves in time to ensure the safety and stability of the production process.
2.Pharmaceutical field: In the pharmaceutical industry, pressure relays are responsible for real-time monitoring of the pressure of pharmaceutical equipment.
Once abnormal pressure fluctuations occur, it can quickly take corresponding measures, such as closing valves and starting emergency pumps, to prevent equipment damage and ensure drug quality.

Then, the working principle of pressure relay
Pressure relays are mainly composed of springs, diaphragms, pipelines, etc.
Under normal conditions, the elastic force of the spring causes the diaphragm to close tightly, thereby preventing current from passing through the pipeline.
When the pressure reaches the preset value, the deformation of the spring causes the diaphragm to open, allowing current to pass through the pipeline, and the circuit is connected.
On the contrary, when the pressure decreases, the elastic force of the spring will cause the diaphragm to close again, cutting off the current, thereby closing the circuit.

Finally, application examples of pressure relays
Taking the petrochemical industry as an example, pressure relays can be connected in series in the control circuit of production equipment.
When the pressure in the equipment reaches the preset safety upper limit, the pressure relay will quickly trigger the alarm device to notify the operator to take timely countermeasures, such as opening the exhaust valve to reduce the pressure.
If the pressure continues to rise to a level that endangers the safety of the equipment, the pressure relay will automatically disconnect the control circuit and stop the operation of the equipment, thus protecting the equipment from damage.