Pressure Switch Operating Principles and Features

The pressure switch is a simple pressure control device. When the measured pressure reaches the rated value, the pressure switch can send an alarm or control signal. The general working principle of the pressure switch: When the pressure in the system is higher or lower than the rated safety pressure, the inner membrane piece of the sensor moves instantaneously, and the switch connector is pushed or disconnected by connecting the guide rod, when the pressure is reduced. When the rated recovery value is increased, the diaphragm is instantaneously reset, the switch is automatically reset, or simply when the measured pressure exceeds the rated value, the free end of the elastic element is displaced, and the switching element is directly or after the comparison to change the switch. The on-off state of the component achieves the purpose of controlling the measured pressure. The elastic components used in pressure switches include single-ring spring tubes, diaphragms, bellows, and bellows. Switching elements include magnetic switches, mercury switches, and micro switches.
The main categories of pressure switches include normally open and normally closed. The main features are:
1. It adopts inch pipe thread quick joint or copper pipe welding type installation structure, which is flexible to install and easy to use. No special installation and fixation are required.
2, insert type wire connection for users to choose.
4. The sealed stainless steel sensor is safe and reliable.
5, within the pressure range can be manufactured according to any user selected pressure value.
Main applications of pressure switch: Mainly used for high and low pressure protection control of home, commercial, and automotive refrigeration systems, steam conditions and power stations; accumulators, receivers, flash tanks, separators, scrubbers, oil refining equipment . It can also be applied to high and low pressure protection control of various equipment tools.
Pressure switch used in the air compressor is mainly to adjust the start and stop state of the air compressor, by adjusting the pressure in the air tank to allow the air compressor to stop the rest, the maintenance of the machine. In the air compressor factory debugging , According to customer needs to adjust to the specified pressure, and then set a pressure difference. For example, the compressor starts to start, pumping gas to the gas tank, to the pressure of 10kg, the compressor is stopped or unloaded, when the pressure to 7kg when the air pressure The machine starts to start again. There is a pressure difference between the two. This process allows the compressor to take a rest and achieve the function of protecting the air compressor. The motor directly drives the compressor and causes the crankshaft to rotate and drives the connecting rod to reciprocate the piston. , causing cylinder volume changes. Due to the change of the pressure in the cylinder, the air is passed through the air filter (muffler) through the intake valve into the cylinder. During the compression stroke, the compressed air passes through the exhaust valve due to the reduction of the cylinder volume, and the mass flowmeter is exhausted. The check valve (check valve) enters the air tank. When the discharge pressure reaches the rated pressure of 0.7MPa, it is automatically stopped by the pressure switch. When the pressure of the gas tank drops to 0.5--0.6MPa, the pressure switch is automatically connected to start.
Electronic pressure switches instead of various mechanical pressure switches have gradually become the mainstream of applications. Pumps that usually have pressure switches are high-pressure pumps, such as pumps that send water to high buildings. In order to allow a certain pressure to be reached, the pump stops, avoiding no load, but the pumps are always there, wasting electricity, and storage tanks. The function will not let the pressure be lost immediately, so not a large number of water pumps will not start. When the pressure of the tap water pipe or air pump is lower than the lower limit of the switch pressure adjustment point, the switch is automatically turned on and the pump starts to operate, when the water pipe or the air pump When the pressure is greater than the upper limit of the switch pressure adjustment point, the switch is automatically disconnected and the pump is stopped. The upper and lower limit of the switch pressure can be adjusted within the adjustment range depending on the water height and the required pressure of the air pump.