How to read and understand boiler pressure gauges

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It is understood that boiler pressure gauges are very important, as they are used for measuring the pressure in boilers. Precautions for their design and installation include: (1) Each boiler must be equipped with a pressure gauge that is directly connected to the steam space of the boiler drum. Pressure gauges should be installed in front of the feedwater control valve, at the outlet of the split economizer, at the outlet of the superheater, and between the main steam valve. (2) In boilers or pressure vessels whose working medium is high-temperature steam, a trap must be installed on the pipe connecting to the pressure gauge, so that the steam can condense within this trap and prevent it from entering directly into the gauge’s spring tube. This prevents the components inside the gauge from overheating and deforming, thus maintaining the accuracy of the pressure gauge. When steel pipes are used for trap pipes, their inner diameter should not be less than 10 mm. A three-way stopcock should be installed between the pressure gauge and the trap, to allow for cleaning of the pipeline, replacement, and calibration of the pressure gauge. http://www.dy88.cn/file/upload/201012/10/14-15-00-10-1.jpg (3) According to the maximum allowable pressure of the boiler or pressure vessel, mark a warning red line on the gauge dial. However, the warning line should not be drawn on the gauge glass, to avoid illusions caused by the rotation of the glass that could lead to accidents. (4) Pressure vessels used to hold high-temperature, highly corrosive, or highly viscous media should be equipped with a liquid-filled isolation device on the piping connecting the pressure gauge to the vessel, or corrosion-resistant diaphragm or bellows-type pressure gauges should be used. (5) The location where the pressure gauge is installed should have sufficient lighting to facilitate observation and inspection by the operator. The pressure gauge must be protected from radiant heat, low temperatures, and vibrations. (6) To facilitate the replacement and calibration of the pressure gauge, a tee cock should be installed between the pressure gauge and the pressure-bearing equipment; the cock shall be mounted on a vertical pipe section and shall be equipped with an opening indicator and a locking device.