When to choose a diaphragm pressure gauge? How to choose? This is a problem that many customers encounter when purchasing pressure gauges. Today, the editor will explain it in detail to you:

Under what circumstances should a diaphragm pressure gauge be selected?

Whenever we encounter measuring the pressure of general gases, water, and oil when choosing a pressure gauge, we can choose a general pressure gauge; When measuring the pressure of nitric acid, phosphoric acid, and strong alkali, a stainless steel pressure gauge can be used. However, when encountering media with strong corrosiveness (such as hydrochloric acid, wet chlorine gas, ferric chloride), high viscosity (such as latex), easy crystallization (such as saltwater), easy solidification (such as hot asphalt), and solid floating matter (such as sewage), it is not feasible to use the above general pressure gauge and stainless steel pressure gauge because even SUS316 stainless steel pipes can be corroded by hydrochloric acid. Floating matter in asphalt and sewage will quickly block the pressure gauge's pressure hole, causing the instrument to lose its function. At this point, we need to consider choosing a diaphragm pressure gauge.

Secondly, diaphragm pressure gauges can solve on-site working conditions such as corrosion and blockage of media. Different corrosion-resistant diaphragm materials can be selected according to different highly corrosive media to achieve anti-corrosion effects. Due to the presence of a diaphragm, it can prevent high viscosity, easily crystallized, and solidified media from flowing into the pressure hole, ensuring the normal operation of the instrument. Diaphragm pressure gauges are widely used for pressure measurement in production processes in industrial sectors such as petrochemicals, metallurgy, power, food and pharmaceuticals.

Thirdly, advantages of diaphragm pressure gauge products:

The difference between a diaphragm pressure gauge and a general pressure gauge is that when measuring pressure with a general pressure gauge, the measured working medium directly enters the spring tube, while when measuring with a diaphragm pressure gauge, the measured working medium cannot enter the spring tube. There are two benefits to this:

1. The materials used for manufacturing spring tubes in diaphragm pressure gauges are brass tubes, tin green copper tubes, 1Cr18Ni9 stainless steel tubes, and SUS316 stainless steel tubes. As for other corrosion-resistant materials such as pure titanium, pure titanium, Hastelloy, Monel alloy, etc., pipes are difficult to purchase due to limited use, but strip materials used to make membranes are much easier to purchase.

2. When measuring the pressure of high viscosity, easily crystallized, and easily solidified media, diaphragm pressure gauges can ensure the normal requirements of the instrument due to the isolation effect of the diaphragm.

Fourthly, there are several structural forms of diaphragm pressure gauges:

1. Threaded connection

Diaphragm pressure gauge: Threaded diaphragm pressure gauge, commonly used to measure the pressure of highly corrosive gases or liquids. The membrane is generally welded to the lower end of the upper connecting body, and the upper and lower connecting bodies are fastened with bolts.

2. Flange connection

Diaphragm pressure gauge: A flange connected diaphragm pressure gauge, commonly used to measure the pressure of media with strong corrosiveness, high viscosity, easy crystallization, easy solidification, or solid floating matter. The heat dissipating flange diaphragm pressure gauge shown in Figure 4-8 is suitable for measuring the pressure of media with corrosiveness and high temperature.

3. Sanitary clamp connection

Diaphragm pressure gauge: a sanitary clamp connection, mainly composed of a pressure gauge head, an upper connector, and an installation clamp. This type of connection is currently not widely used in China, and is commonly used in imported food and pharmaceutical processing equipment for measuring pressure at higher temperatures with particles and sediments. Due to the ease of disassembly and installation of the clips used for connection, which are particularly beneficial for cleaning the outer film and can meet the disinfection and cleaning needs of the food industry, this type of connection will become increasingly common in the future. Some countries and enterprises in China refer to this type of diaphragm pressure gauge as a sanitary diaphragm pressure gauge.

4. Diaphragm pressure gauge: hose connection hose connection diaphragm pressure gauge, also known as remote diaphragm pressure gauge, is mainly composed of a pressure gauge head, a metal hose, and a diaphragm connector. This type of connected diaphragm pressure gauge is commonly used for measuring environments with harsh conditions, high equipment vibration, high medium temperature, or difficult to observe up close, and the working medium is often corrosive.