Validity period for pressure gauge calibration

The validity period for calibrating pressure gauges is generally two years.

I recall that pressure gauges are inspected every six months, but I can’t find the exact source for this information.

When the pressure gauge is used as a safety accessory, the calibration interval is 6 months; otherwise, it is 1 year. That’s what the quality inspection agency said.

http://bbs.hcbbs.com/viewthread.php?tid=297232； http://bbs.hcbbs.com/viewthread.php?tid=274155.

Once every six months, as specified in \"General Gauge Tubes for Pressure, Pressure-Vacuum, and Vacuum Meters\"

It should be half a year. \"General pressure gauges of the Bourdon tube type, pressure-vacuum gauges, and vacuum gauges\" (JJG52-1999), 5.5: \"The calibration period for pressure gauges should generally not exceed six months.\" \"Digital Pressure Gauges\" (JJG875-2005) 5.5: \"The calibration cycle can be determined based on the operating environment conditions, frequency of use, and operational requirements of the pressure gauge; it generally should not exceed 1 year.\" For pressure gauges whose indicated values are unstable and do not meet the requirements, the calibration interval is generally no more than six months. ”

The management of pressure gauges (which fall under the category of measuring instruments) is generally carried out in three categories: A, B, and C. Category A requires a higher level of precision and is used in important or critical equipment and facilities such as boilers; the calibration cycle for these devices is usually six months. The organizations responsible for calibration must possess the appropriate qualifications. In the past, this task was mainly handled by the Quality and Technical Supervision Bureaus, but now it is sufficient to have the appropriate qualifications； The accuracy requirements for Class B and Class C are relatively lower, with a calibration cycle of generally one year.

If one examines carefully the principles for the classified management of measuring equipment outlined in ISO10012, measuring equipment – including field pressure gauges – can be classified into categories A, B, and C depending on their usage requirements. Equipment in category A falls under mandatory inspection, and it must be calibrated according to the specified periodicity for such inspections； Category B falls under periodic calibration, and the metrology department can determine the calibration interval based on the actual conditions on site ； Class C involves a one-time inspection; no inspection is required if there is no damage. Generally, pressure gauges for safety valves and those on boilers fall under Category A mandatory inspection ； Most pressure gauges fall under Category C management. As for the service life of pressure gauges, it is related to the type chosen. For measuring the pressure at various outlets of compressors and pump outlets, if ordinary pressure gauges are used, their service life will certainly not be long enough to cover the compressor’s maintenance cycle, which is what LZ mentioned. However, if a shock-resistant pressure gauge (filled with oil) is used, its proper service life will definitely be extended, thereby allowing for synchronization with the maintenance of compressors and pumps and reducing the need for unplanned replacements. Discussion is welcome. For classified management, do pressure gauges that cannot be replaced fall under category C?

Generally, it is stipulated that pressure gauges are divided into three categories: A, B, and C. For Category A special critical components, such as those found on pressure vessels, inspections are carried out every six months. Category B components, which are used for important parameters such as process control points, require inspections once a year. For general parameters of Category C. It is intended for single-use over its entire lifespan; that is, once the new gauge has been calibrated by the measurement department, it is used until it breaks.

For spring pressure gauges, it is generally reasonable to conduct a regular calibration every six months, as their service life is short. Although national standards specify a longer period, companies can determine the appropriate timing based on their own specific conditions (such as the type of medium used, operating conditions, and degree of wear). In principle, this period should not exceed the limits set by the standards. The personnel responsible for installing and maintaining these devices, or those in charge of production processes, can decide on the appropriate calibration schedule based on actual circumstances; it may also be less than six months. For special types of pressure gauges, such as those with diaphragms that are difficult to remove, the designated calibration period can be longer, but still must not exceed the limits set by national standards. There is also a difference between the calibration period and the verification period: the verification period can be longer than that specified by the calibration authorities, but still shorter than the limits set by national standards

According to the practices of state-owned enterprises, pressure gauges are classified, and the calibration interval is determined based on their level of importance; those that are more critical require calibration every six months, while those that are less important need to be calibrated once a year. In fact, there is no mandatory requirement for calibrating pressure gauges, so it’s not necessary to do so.

\"General pressure gauges of the Bourdon tube type, pressure-vacuum gauges, and vacuum gauges\" (JJG52-1999), 5.5: \"The calibration period for pressure gauges should generally not exceed six months.\"

The management of pressure gauges (which fall under the category of measuring instruments) is generally carried out in three categories: A, B, and C. Category A requires a higher level of precision and is used in important or critical equipment and facilities such as boilers; the calibration cycle for these devices is usually six months. The organizations responsible for calibration must possess the appropriate qualifications. In the past, this task was mainly handled by the Quality and Technical Supervision Bureaus, but now it is sufficient to have the appropriate qualifications； The accuracy requirements for Class B and Class C are relatively lower, with a calibration cycle of generally one year.

The regulations vary: pressure gauges used in petrochemical production are generally inspected once a year, those used for calibrating safety valves are inspected every six months (as specified in the regulations for safety valve inspection), and pressure gauges used for conducting hydrostatic tests on gas cylinders are generally inspected once a month.