The pressure gauge is used to measure and indicate the size of the pressure in the pressure product. If the pressure product does not have a pressure gauge, or the pressure gauge fails, the pressure of the pressure product cannot be expressed, thereby directly endangering safety.
The pressure product is equipped with a sensitive and accurate pressure gauge, so that the operator can operate the pressure product correctly with the pressure gauge to ensure safe and economical operation.
The pressure gauge can accurately indicate the level of steam pressure in the pressure product. The operator can adjust the heating degree of the product according to the indicated value of the pressure gauge to ensure the requirements of the gas department and the safe operation of the pressure product.
Working principle of pressure gauge
The pressure gauge passes the elastic deformation of the sensitive elements (Bourdon tube, bellows, bellows) in the table, and then the pressure change is transmitted to the pointer by the conversion mechanism of the movement in the table, causing the pointer to rotate to display the pressure.
Five common pressure gauges
1. Spring tube pressure gauge
The working principle of the spring tube pressure gauge is: an oval spring tube made of phosphor copper is installed in the watch case, one end of the tube is fixed and connected to the water storage elbow, and the other end is closed and connected to the connecting rod and lever , The pointer is fixed on the pinion shaft. When the spring tube is compressed, it expands from an ellipse to a circle, forcing the spring tube to extend outward. The higher the pressure, the greater the extension. This action is transmitted to the pointer through the lever, lever, sector gear, pinion, and the pointer rotates. Pressure out of the container. When there is no pressure in the container, the spring tube returns to its original state and the pointer returns to zero. The pointer indicates gauge pressure, and the unit scale should be MPa.
2. Electric contact pressure meter
The electric contact pressure gauge is based on the spring tube in the measuring system under the pressure of the measured medium, forcing the end of the spring tube to produce a corresponding elastic deformation-displacement, which is transmitted through the gear transmission mechanism and amplified by the tie rod. The indicator (together with the contacts) indicates the measured value one by one on the dial. At the same time, when it comes into contact with the contact (upper or lower limit) on the set pointer (moving off or moving), the circuit in the control system can be disconnected or connected to achieve automatic control and development. Letter the purpose of the alarm.
3. Capacitive pressure sensor
It generally uses a round metal film or a metal-plated film as an electrode of the capacitor. When the film is deformed by pressure, the capacitance formed between the film and the fixed electrode changes, and the output can be related to the voltage through the measurement circuit. electric signal. Capacitive pressure sensors are capacitive sensors with variable pole distances, and can be divided into single capacitive pressure sensors and differential capacitive pressure sensors.
4. Strain type pressure sensor
Strain-type pressure sensor is a kind of sensor that is widely used in pressure sensors. It is generally used to measure larger pressures. It is widely used in measuring internal pressure of pipelines, pressure of internal combustion engine gas, pressure difference and injection pressure, engine and missile tests Pulsating pressure, and fluid pressure in various fields.
5. U-shaped pressure gauge
Principle of U-shaped manometer: When the U-shaped manometer is not connected to the pressure measuring point, the liquid levels on both sides of the U-shaped glass tube are equal at the zero scale line. When one end of the U-shaped tube communicates with the pressure measurement point, the liquid level in the U-shaped tube will change. If the liquid level on the side communicating with the pressure measurement point drops, it means that the pressure at the pressure measurement point is positive pressure, otherwise it is negative pressure.