What are the requirements for selecting a pressure gauge? 【Video】

1. The selection of pressure gauges, as well as their safe maintenance and management, are extremely important. 2. A few years ago, in a chemical plant where I worked, the pressure gauge on a hydrogen pipeline was installed incorrectly, which caused hydrogen to burst through the gauge and leak out, leading to a fire. This resulted in an accident in which a hydrogen-powered vehicle caught fire. The specific situation is as follows: the hydrogen skid unit is connected to the pressure reduction valve assembly using high-pressure steel wire hoses; at the front end of the pressure reduction valve assembly there is a high-pressure gauge with a range of 20 MPA ； Behind the pressure relief valve assembly is a pressure gauge with a range of 1.6 MPA. Due to the semi-annual calibration of pressure gauges, they were removed for calibration and then reinstalled afterward. The machine repair team leader casually installed the low-pressure gauge with a reading of 1.6 MPA in place of the high-pressure gauge. During the replacement of the jack at night, the hydrogen gas inside the flexible high-pressure steel tube of the jack punctured the low-pressure gauge, causing a leak and an explosion; the flames spread several meters away, resulting in a truly terrifying fire. Fortunately, the hydrogen skid truck is outside the workshop. Thanks to the firefighters’ efforts to cool things down with water and shut off the valves, an explosion was averted. 3. The lessons learned from blood and tears remind us that pressure gauges are safety devices, and it is necessary to assign dedicated personnel for their maintenance and supervision.