The working principle of the pressure gauge. Through the elastic deformation of the sensitive elements (Bourdon tube, bellows, bellows) in the watch, the pressure deformation is transmitted to the pointer by the conversion mechanism of the movement in the watch, causing the pointer to rotate to display the pressure. Bourdon tube (Bourdon tube) is divided into type tube, coil spring tube, spiral tube, etc., generally cold-work hardened material billet tube, which has high plasticity in the annealed state, and is cold-work-hardened and qualitatively treated by pressure processing Obtain high elasticity and strength. Under the action of the pressure in the inner cavity of the spring tube, using its elastic characteristics, the pressure can be conveniently converted into the elastic displacement of the free end of the spring tube. The measurement range of the spring tube is generally when the diaphragm sensitive element is a circular diaphragm with waves, the diaphragm itself is located between two flanges, or is welded to the flange or the edge is clamped between the two flanges. between. One side of the diaphragm is subjected to the pressure of the measuring medium, so the slight bending deformation produced by the diaphragm can be used to indirectly measure the pressure of the medium, and the size of the pressure is displayed by the pointer. Compared with the Bourdon tube, the diaphragm has a larger transmission force. Because the periphery of the diaphragm itself is fixed, its vibration resistance is better. The diaphragm pressure gauge can achieve high overpressure protection (for example, the diaphragm is attached to the upper flange), and the diaphragm can also be coated with a protective coating to improve corrosion resistance. It can be used with open flanges, flushing, and openings. Diaphragm pressure gauge measures the medium with high viscosity, dirty and crystallization, the pressure measurement range of diaphragm pressure gauge is 1600Pa ~ 2.5 MPa.
The sensitive element of the bellows is composed of two diaphragms with a circular wave cross-section that are buckled together. The pressure of the measuring medium acts on the inside of the bellows cavity. The resulting deformation can be used to indirectly measure the pressure of the medium. The size is shown by the pointer. The bellows pressure gauge is generally used to measure the micro pressure of the gas, and has a certain degree of overpressure protection. Several bellows sensitive components are stacked together to produce a large transmission force to measure extremely small pressure. The pressure measurement range of the bellows pressure gauge is 250Pa ~ 60000Pa
Pressure gauges commonly used in industrial boilers and chemical industries include liquid column pressure gauges, spring pressure gauges, bellows pressure gauges, shock-resistant pressure gauges, and digital pressure gauges.
diaphragm pressure gauge
Capsule pressure gauge measures the micro pressure and micro negative pressure of blast, induced air, flue gas and powder milling systems. The main structure of the bellows-type pressure gauge is composed of two parts: a bellows and a transmission amplifying mechanism. The diaphragm is a round box-shaped pressure-sensitive element made of an alloy. When it is subjected to pressure changes, it will expand or contract and be displaced. Through the transmission and amplifying lever system, the pointer is indicated on the groove-shaped dial. Measure the value of micro pressure or micro negative pressure. The bellows pressure gauge can also be charged with contacts to achieve control and protection functions.
spring tube pressure gauge
The structure of the spring tube pressure gauge. In the circular shell, there is a spring elbow (commonly made of seam phosphor bronze tube or seamless steel tube) with an elliptical section (the long axis of the ellipse is parallel to the center axis of the hand), one end of which is connected to the boiler The water storage pipe leading from the steam space communicates with a fixed end, and the other end is a closed free end, which is connected with a connecting rod. The other end of the connecting rod is a sector gear, which is connected with a pinion on the central shaft. The pointer of the pressure gauge is fixed on the central axis.
When the special spring tube is under pressure from the medium, it will make its free end move outward, and then drive the sector gear and pinion to rotate through the connecting rod, so that the pointer rotates an angle in the clockwise direction. The greater the pressure of the medium, the greater the rotation angle of the pointer. At this time, the scale value indicated by the pointer on the dial of the pressure gauge is the value of the steam pressure in the boiler. When the pressure drops, the spring elbow will contract inward, returning the pointer to the corresponding position. When the pressure disappears, the spring elbow returns to its original shape, with the help of the hairspring, the pointer returns to the starting point (zero position). Bourdon tube pressure gauge has the advantages of compact structure, high accuracy, wide measurement range, convenient use, etc. It is mostly used to measure the pressure value of the medium in the drum, header and pipeline.
liquid column pressure gauge
The working principle of liquid column pressure gauge is to use the pressure generated by the height difference of the liquid column (water or mercury) on both sides of the U-shaped glass tube to balance the pressure of the measured medium. The greater the difference in height of the liquid column, the greater the pressure of the measured medium, and the pressure value can be directly read from the scale.
Liquid column pressure gauge has the advantages of simple structure, convenient use, low price, etc., but it cannot measure higher pressure, and cannot automatically indicate and record. Therefore, the scope of use is limited. It is usually used to measure the pressure value in the furnace and flue of the boiler. The shock-resistant pressure gauge is composed of a pressure guiding system (including joints, spring tubes, flow-limiting screws, etc.), a gear transmission mechanism, an indicating device (pointer and dial), and an outer shell (including case, cover, watch glass, etc.).
Vibration-resistant pressure gauge
The shock-resistant pressure gauge shell is an airtight structure, which can effectively protect the internal parts from environmental influences and dirt intrusion. The shock-resistant pressure gauge is a meter filled with a damping fluid (usually silicone oil or glycerin) in the shell, which can resist vibration in the working environment and reduce the pulsation of medium pressure. Vibration-resistant pressure gauge [applicable to places with severe environmental vibrations, can withstand the pulsation, impact and sudden unloading of the medium, and the indicator is stable and clear. It is widely used in machinery, petroleum, chemical, metallurgy, mining, electric power and other departments to measure the pressure of non-corrosive media on copper and copper alloys.
Digital pressure gauge
Digital pressure gauge is an online measuring instrument. It adopts battery long-term power supply, no external power supply is needed, and it is easy to install and use. This product has been widely used in petroleum, chemical, electric power and other fields through a pressure gauge that displays the measured pressure in digital form. The digital pressure gauge has high precision, high stability, error ≤1%, internal power supply, micro power consumption,  stainless steel casing, solid protection of the digital pressure gauge