How to select a pressure gauge

At present, the following types of pressure gauges are commonly used under on-site working conditions: ordinary pressure gauge; stainless steel pressure gauge; seismic-resistant pressure gauge; membrane pressure gauge; membrane seismic-resistant pressure gauge; electric contact pressure gauge; seismic-resistant electric contact pressure gauge; diaphragm pressure gauge; diaphragm pressure gauge; resistance remote transmission pressure gauge; differential pressure gauge; precision digital pressure gauge, etc.

Pressure gauges are widely used in chemical, petroleum, metallurgy, mining, electric power and other production. They are the most commonly used measuring instruments for displaying and controlling pressure. They are like human eyes and play a huge role in the production process of enterprises.

When selecting pressure instruments, we often fall into such misunderstandings. Selection of pressure gauges: Ordinary pressure gauges are selected without considering the medium. The spring tube of ordinary pressure gauges is made of copper. If used in corrosive media, the service life of the pressure gauge will be greatly reduced. A chemical company sent 15 pressure gauges at one time. After inspection, repair and verification, only 3 were qualified, and the rest of the pressure gauges were scrapped because the spring tubes were corroded or damaged. After that, stainless steel pressure gauges were selected, and there was no phenomenon of pressure gauges being scrapped due to corrosion.

Use a large range of pressure gauges where the pressure changes frequently. In some compressors or pumps where the outlet pressure changes frequently, use a large range of pressure gauges to prevent damage to the pressure gauge. In fact, this method does not help. The transmission principle of the pressure gauge is that the deformation of the spring tube is meshed with the fan gear and the cylindrical gear and the pointer is rotated through the oil thread. If the pointer of the pressure gauge rotates frequently at a certain angle, the gear at this angle will wear and cause damage to the movement. The damaged position of the pressure gauge of a liquefied petroleum gas company is always the gear wear. After replacing it with a shock-resistant pressure gauge, the effect is obvious.

In addition, in order to ensure that the elastic element can work reliably within the safe range of elastic deformation, the selection of the pressure gauge range should not only be based on the size of the measured pressure but also consider the speed of change of the measured pressure, and the range should leave enough room. When measuring stable pressure, the maximum working pressure cannot exceed 2/3 of the range; when measuring pulsating pressure, the maximum working pressure cannot exceed 1/2 of the range; when measuring high pressure, the maximum working pressure cannot exceed 3/5 of the range. In order to ensure measurement accuracy, the minimum working pressure measured cannot be lower than 1/3 of the range, that is, the range within the red line on the dial.