Calibration of pressure gauges showing (workers) for the medium air/water up to 60 MPa — what to consider

Krympress reports:

Manometers designed to measure air and water pressure in the range of up to 60 MPa belong to the category of working measuring instruments, on the accuracy of which technological processes, safety and efficiency of equipment operation depend. One of the key procedures to maintain the accuracy of these devices is calibration.

What is the calibration of the pressure gauge?

The calibration of the manometer is the process of determining the metrological characteristics of the device (primarily the accuracy of the readings) with the subsequent comparison with the reference values ​​of the pressure https://calibronromc.ru/product/kalibrovka-manometrov/. It is carried out without amendments to the design of the device and serves to identify the discrepancies between the actual and reference data.

Unlike verification, calibration can be performed both within the framework of metrological control and at the initiative of the owner of the equipment, without mandatory registration of results in state registers.

Why is calibration carried out?

The purpose of calibration is to establish the correspondence of the manometer readings with the requirements of accuracy. This is necessary for:

• ensuring the reliability of pressure indications;

• prevention of accidents and equipment failures;

• compliance with industrial standards and safety regulations;

• preparation of the device for state verification;

• Improving control over technological processes, especially in highly loaded or potentially dangerous systems.

When is the calibration required?

Calibration can be carried out in the following cases:

Planned

It is recommended to carry out calibration regularly — at least once a year. The frequency can be increased depending on the operating conditions, criticality of the equipment, the intensity of use and the requirements of the enterprise standards.

After repair

If the manometer was repaired, disassembled, replaced by elements or tuning, it is necessary to calibrate to make sure that the readings are accurately after the intervention.

Before state verification

Calibration allows you to identify deviations in advance, which can lead to a refusal during official verification.

If unstable indications are detected

If the device began to demonstrate the indications suspiciously unstable or deviating from the norm, the calibration will help to determine whether the device is really faulty or has permissible error.

When changing operating conditions

Changing the working environment, temperature, vibration loads, pressure — all this can affect the characteristics of the device. Calibration allows you to make sure of its suitability for new conditions.

Urgent calibration: when you can not do without it

There are a number of situations in which calibration becomes an emergency procedure:

• Suspicion of incorrect indications for pressure growth. Especially critical in high -pressure systems (30-60 MPa), where accuracy is important for safety.
• An accident or an abnormal situation. After such events, you need to make sure of the accuracy of the equipment.
• Preparation for a certification audit. Some standards (for example, ISO, GOST R) require confirmation of the accuracy of manometers.
• The exit beyond the admission during visual inspection. For example, deformation of the arrow, condensate under glass, trembling of the arrow — all this is an occasion for urgent calibration.

Preventive calibration: is it worth doing?

Yes, preventive calibration is a reasonable step for enterprises striving for process stability and avoiding unscheduled downtime. Regular calibration:

• minimizes the risk of sudden failures;
• extends the life of the device;
• allows you to in advance to identify trends to displacement of indications;
• Saves resources — it is easier to calibrate than to then repair or explain the consequences of faulty pressure control.

Prevention is especially relevant for manometers working in conditions:

• high humidity;
• vibrations;
• temperature drops;
• dustiness;
• frequent disconnect/turning on the system.

Who is calibrating?

Calibration have the right to carry out:

1. Accredited metrological laboratories included in the register of Rosakkreditation or a similar organization, depending on the country.
2. Metrological control services at the enterprise, if they have appropriate equipment, staff qualifications and current accreditation.
3. Specialized organizations that provide an exit or stationary calibration service.

Important: the calibration staff must be trained and have admission to work with high -pressure devices.

Equipment for calibration

The following tools are used for calibration of pressure gauges:

Reference pressure gauges

High accuracy manometers that have passed verification and certification. Used to compare readings.

Piston (membrane) manometers

Exemplary devices used in state or factory laboratories.

Press Calibrators

They allow you to create controlled air or liquid pressure and connect both a calibrated and reference device. Especially convenient for working at the location.

Automated calibration stands

Allow you to calibrate several devices simultaneously with fixing the results in software.

Pressure comparators

They are used to accurately compare the pressure between the calibrated and reference device.

Additionally, adapters, fittings, sealing materials and means of registering results are used.

How is the calibration procedure

The general order includes:

1. External inspection of the manometer.
2. Checking the zero position of the arrow.
3. Connection to a calibration stand or a press calibrator.
4. The supply of pressure in the range is from 0 to maximum (in this case — up to 60 MPa) with fixed steps.
5. Comparison of readings with the standard.
6. The conclusion about the suitability and execution of the protocol.

Depending on the conditions, calibration is carried out at one or several points of the scale. It is allowed to conduct in an increased and reduced cycle for assessing stability and hysteresis.

What will happen if not calibrated?

Ignoring calibration can lead to the following consequences:

• Loss of measurement accuracy. Which is especially critical at a pressure above 25 MPa.
• Deviation from regulatory requirements. It entails fines and prohibitions on operation.
• Equipment damage. Incorrect indications can lead to overloading pipelines, compressors, pumps.
• accidents. Especially dangerous in boiler houses, GTS, industrial plants.
• Refusal of certification and supply. Contributes can require certified and calibrated devices.
• Distrust of measurement results. Quality and production process control is violated.

Regulatory documents and standard s

Calibration and verification of manometers are regulated by the following documents:

• GOST 2405-88-pressure gauges, vacuum, manovacumometers. General technical conditions.
• RMG 73-2004-State system for ensuring uniformity of measurements. Metrological support of verification and calibration of measuring instruments.
• GOST 8.513-84-State system for ensuring the uniformity of measurements. Monometers are exemplary.
• RD 50-662-88-methodology for calibration of pressure measuring instruments.
• FZ-102 «On ensuring the uniformity of measurements»-the Basic Federal Law of the Russian Federation.

Experts strongly recommend taking into account: calibration of pressure gauges working with air and water up to 60 MPa is the most important procedure that guarantees safety and measurement accuracy. It is necessary not only to comply with the standards, but also for the reliable operation of the equipment. Calibration should be carried out regularly and especially carefully — when changing operating conditions or after identifying problems. The neglect of this procedure can result in serious consequences, both in production and legal terms.

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