Some discussions on the classification of pressure gauges
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This post was last edited by Wang Tianze on 2016-10-10 21:49. In the management of pressure gauges in companies, it is particularly important that the classification of these gauges be accurate and reasonable. As mentioned under Category B, for pressure gauges used in process control, the calibration interval corresponds to the maintenance period of the equipment； Grade C includes two types: one is the pressure gauge used for monitoring, with a calibration cycle of 1–2 years ； The second type is pressure gauges for monitoring; they do not require periodic calibration, and they need to be replaced as soon as a failure occurs ； So the question is, in Category B, which pressure gauges refer to process control? Pump outlet pressure gauge? Which pressure gauges are referred to as those monitored in Class C? Gauge for utility parameters pressure? What are the pressure gauges used for monitoring? I also ask everyone to share their personal opinions more
I understand that the pressure gauge involved in process control should refer to a pressure transmitter
Regarding on-site gauges, the pressure gauges installed on pressure vessels and pressure pipelines in our facility are of Class A, while those of other types are of Class C
I’m an amateur; I’ll share my guesses. The pressure gauges to be used for monitoring should primarily be those related to pressures that change in tanks, reactors, and similar devices, as well as those related to the design process parameters. If the pipes downstream of the pump also lead into the reactor, then a pressure gauge installed downstream of the pump should also be considered. What should be monitored are those systems where the pressure, such as steam or compressed air, remains practically constant.
Pressure vessels, pressure pipelines, and pressure gauges related to safety, hygiene, and trade handovers all fall under Category A and are calibrated every six months; the rest belong to Category B and are calibrated according to the maintenance cycle of the equipment. There is no Category C.
Ordinary pressure gauges are of Class C, while those that are more precise and have higher accuracy fall into categories above Class C; that’s all I know. After reading your explanations, I gained some further knowledge about pressure gauges. Thank you!
Pressure vessels and pipelines: A for those where pressure is involved in control, interlock valves, or other conditions; B for pumps; C for everything else
1. Pressure gauges used for safety protection must undergo mandatory calibration. Including the following 7 categories: a. Measurements of the main boiler cylinder and the feedwater pressure area ； b、Measurement of the pressure in the air reservoir and main pipes of fixed air compressors ； c. Measurement of generator and turbine oil pressure as well as locomotive pressure ； d. Measurement of pressure in medical autoclaves and pressure cookers ； e. Pressure measurement with alarm device ； f. Measurement of the pressure in a sealed pressurized container ； g. Measurement of pressure in hazardous, toxic, and highly corrosive media. (e.g.: Bourdon tube pressure gauges, electric remote transmission and electrical contact pressure gauges). This one without clear pipes can be classified as Grade A
Pressure vessels, pressure pipelines, and hazardous chemical storage tanks are all classified as A; everything else is classified as B. It’s not difficult to attach a certificate of internal inspection either. (That is, refer to Class C management)
Instrument certificates are generally divided into three grades, A, B, and C, depending on the importance of the location where they are used. Grade A instruments are generally used in locations where strict pressure control is required, and where accurate indication is essential; they are instruments that require close monitoring, typically being inspected once a year or every six months ； Grade B instruments are generally used in locations where strict pressure control is required, and where accurate indication is essential; they are used for routine monitoring, with inspections typically carried out once a year or every two years ； Class C instruments are generally used in locations where pressure control is not stringent; they can be used as a reference value. They are instruments that do not require monitoring, and are usually inspected once every few years or replaced after they cease to function ；