Procedure and timing for checking the serviceability of pressure gauges – Checking pressure gauges: methodology, frequency, timing, requirements

Conducted:

1) every shift - The serviceability of the pressure gauge is checked using a three-way valve by setting the pressure gauge needle to zero, which is recorded in the shift log;

Checking the proper operation of the boiler pressure gauge - the so-called zero test - is performed in the following order:

a) the reading of the pressure gauge in the working position is noted and remembered;

b) by slowly turning the plug of the three-way valve to the left a quarter turn, the pressure gauge is disconnected from the boiler and connected (communicated) with the atmosphere; in this case, the pressure gauge needle should quickly but smoothly return to zero;

c) by turning the plug of the three-way valve to the right a quarter turn, the pressure gauge is again connected to the boiler; in this case, the arrow should quickly and smoothly return to its previous position; this will mean that the pressure gauge is working properly; the accuracy of its readings can only be confirmed by the readings of the control pressure gauge.

In cases where, when checking the serviceability of the pressure gauge, it is discovered that the pressure gauge needle does not go to zero when the pressure gauge communicates with the atmosphere or falls unevenly, jerkily, this means that the pressure gauge fitting and the three-way valve are clogged. It is necessary to immediately blow out the three-way valve; to do this, turn the three-way valve so that water (or gas, when checking gas pipelines) comes out. After purging, the three-way valve is set to its working position.

2) In addition to the specified check, the administration is obliged to do so at least once every 6 months. check working pressure gauges with a control working pressure gauge that has the same scale and accuracy class as the pressure gauge being tested, recording the results in the control check log.

3) At least once every 12 months. pressure gauges must be checked with a stamp or seal installed in the manner prescribed by Rosstandart of Russia. monthly - with the instrumentation and automation service - checking the operation of the boiler protection, the check is accompanied by a deviation of the parameters by simulation, and the results of the check are recorded in the operational log.

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Functionality check:

GOST verification rules (frequency or calibration) – 12 months.

Whereas the starting point must be taken - a month from production. Now there are also pressure gauges that can be verified once every 2 years.

That is, the pressure gauge must be checked at least once a year and at the time of release. It is worth noting that the shelf life of the device (in which it is not involved) is not taken into account.

All verifications carried out with a control pressure gauge (in the absence of which a pressure gauge identical to the verification one can be used) are recorded in the inspection log.

The timing of verification procedures is carried out in accordance with the instructions approved by the owners of the vessels.

Regulations for checking pressure gauges: terms and conditions

Checking the readings of working instruments with their subsequent sealing, in accordance with the current GOST, is carried out at least once a year. In addition, the enterprise must carry out a scheduled inspection with a control pressure gauge at least once every six months. Each such check must be accompanied by a corresponding journal entry.

If the necessary control device is not available, you can check it with a sealed working pressure gauge. The main thing is that its scale and accuracy class coincide with the pressure gauge being tested.

Checking pressure gauges: terms, methods, rules

Various measuring instruments can be installed in a compressed air injection system; a pressure gauge has become widespread. Like many other devices, this one must undergo periodic maintenance. Only in this case can you be sure that it will last for a long period, and the readings obtained will be accurate. Let's consider all the features of the pressure gauge checking procedure in more detail.

Frequency of checking pressure gauges

A pressure gauge is a device that measures pressure in a device or container in a certain section of the pipeline. Periodic checking helps avoid major problems. It is worth considering that verification of pressure gauges should be carried out exclusively taking into account the type of device:

In order for the calibration of pressure gauges to be carried out with high efficiency, attention should be paid to their design features. Spirals are characterized by the following features:

1. Inside the housing there is a spiral, which is connected to the transmitting elements. It is made using a special metal with high elasticity.
2. The dial is connected to a spiral, due to which the position of the arrow changes. The dial operates on a mechanical principle and is represented by a scale with an arrow. Typically, units of measurement and other more important information are displayed on the surface.
3. As the pressure increases, the spiral unwinds, causing the needle to deflect to a greater extent. The size of this element determines the range over which measurements can be taken.

Methodology for checking pressure gauges

There are quite a large number of different technologies that allow you to determine the condition of a measuring device. Checking of technical pressure gauges should be carried out exclusively by professionals, since mistakes made can cause a decrease in the accuracy of the readings. Services should only be provided by specialists who have received appropriate permission.

There are several most common verification technologies:

1. When using a hydraulic press. In this case, the measuring device is installed between two elements of the device. It is worth considering that this measurement technology is characterized by low error. There are quite a large number of different types of hydraulic presses, all of them are characterized by their own specific features. This design is found exclusively in specialized stores; to use it you must have certain skills and knowledge.
2. When using a metrological stand. In this case, the main indicators are taken with a minimum error at the established control points. Such a device creates the required pressure in the system. Among the features of using a metrological stand, we note that the measurement errors are quite high. However, the design features make it possible to significantly expand the scope of application of the device, for example, in the case of high pressure in the system.
3. When using a special calibrator. This device can be purchased today in a specialized store for independent verification of the device. When choosing a calibrator, attention is paid to the range of indicators it can be used in. Most of the models work according to the same scheme.

The latter method allows you to check devices that do not require sealing after the procedure.

The device is characterized by high mobility and can be used without special training.

Basic verification methods

Checking the serviceability of pressure gauges and safety valves in accordance with the current GOST must be carried out at least once a year. The following main verification methods exist:

1. Hydraulic Press.
2. Metrological press.
3. Special calibrator.

In addition, it will be useful to know the main signs of a pressure gauge malfunction:

1. If the needle is bent, broken, or cut, the gauge has likely experienced a sudden increase in system pressure caused by the pump cycling on and off or the opening and closing of an upstream valve. Hitting the pointer all the way may damage it. These sudden changes in pressure can cause the Bourdon tube to rupture and cause the pressure gauge to fail.
2. Overpressure. A pressure gauge with a pointer attached to the top indicates that the pressure is above normal. This means that the installed pressure gauge has the wrong pressure range for the application and cannot display the system pressure. As a result, the Bourdon tube may rupture and cause complete failure of the pressure gauge.
3. Mechanical vibration. A misaligned pump, piston compressor, or improperly installed indicator may cause the pointer, lens, lens ring, or backplate to pop out. There may also be traces of black powder on the dial or scratches on the dial from a loose pointer. The movement of the pressure gauge is coupled to the Bourdon tube, and vibration can break the component that transmits the movement, meaning the sphere no longer reflects the pressure of the system.
4. Ripple. Frequent and rapid cycling of fluid through the system causes wear on the moving components of the gauge. This may affect the gauge's ability to measure pressure and will be obvious as the pointer will move randomly. This situation can lead to rupture of the Bourdon tube and complete failure of the pressure gauge.
5. Excessive temperature and overheating. A poorly installed pressure gauge, or located too close to fluids/gas or excessively hot system components, may have a worn dial or a full fluid box due to failure of its components. Elevated temperatures overload the pressure system and affect measurement accuracy by placing stress on the metal Bourdon tube and other pressure gauge components.

Application of hydraulic press

Checking pressure gauges and safety valves must be carried out taking into account all rules and recommendations. If errors are made, the product may lose its accuracy. Main rules of verification:

1. It is necessary to inspect the pressure gauge to determine the condition of the mechanism. If the device is damaged, checking will not even be required. Many defects can be eliminated by replacing the protective glass. In general, the elimination of defects depends on the specific model.
2. At the very beginning of the test, the arrow should be close to zero. This way you can eliminate the risk of error.
3. It is necessary to create conditions corresponding to operational ones. Examples include air humidity and room temperature.

If setting the pointer to zero cannot be carried out, then it will be necessary to use a special bolt for adjustment.

Application of a metrological stand

Pressure gauges can be tested in the field or on a bench. Field testing can save time and troubleshoot problems in a production environment. Multifunction calibrators make this task easy with a single tool. Bench calibration provides an environment in which the gauge can be cleaned, inspected, tested and recertified under standard conditions to achieve the best possible accuracy.

To run the test:

1. It is necessary to isolate the pressure gauge using valves.
2. Connect the pressure gauge to the calibrator or reference pressure gauge. For hydraulic pressure gauges, it is important to remove any gas that may be trapped in the fluid in the gauge, calibrator, and connections by priming the system. When creating pressure, wait a few seconds to stabilize. Compare the readings of the pressure gauge being tested with a reference pressure gauge or calibrator.
3. For hydraulic pressure gauges, it is important to prime the system. This will remove any gas that may have been trapped in the fluid in the gauge, calibrator or connections.
4. When applying pressure, wait a few seconds for the measurements to stabilize. When using a hydraulic hand pump as a source, it may take several minutes for pressure to stabilize due to the thermodynamic effect of fluids.
5. Compare the readings of the pressure gauge being tested with a reference pressure gauge or calibrator.

Using a special calibrator

The basic equipment for testing pressure gauges includes: a reference device, an adjustable pressure source, a means of connecting the pressure gauge to the pressure source and reference device, as well as the tools needed to adjust the pressure gauge mechanisms. Reference measuring instruments are used to transfer the sizes of physical units from standards to working measuring instruments.

Finally, a pressure gauge is one of the simplest and most commonly used tools. It has a simple setup where you can easily calibrate. But the analog pressure gauge is also considered one of the tools where errors are most common. It is very important to know how long it takes to check pressure gauges. Otherwise, there may be many problems with the device.

If you require shut-off valves, then go to the appropriate section of our website.

Checking pressure gauges: rules

Pressure gauges must be checked exclusively taking into account the basic rules and recommendations, since mistakes made can lead to a decrease in the accuracy of the product. The basic rules are as follows:

1. First, the pressure gauge is inspected to determine the condition of the mechanism. Damage to the device may indicate that verification is not worthwhile. Some of the defects can be eliminated, for example, by replacing the protective glass, it all depends on the features of the specific pressure gauge model.
2. The conditions closest to operational ones are created. An example is the indicator of air humidity, atmospheric pressure and temperature in the room.
3. At the beginning of the test, the needle must be at zero. Due to this, the possibility of an error at the time of measurement is eliminated.

If it is not possible to set the needle to zero, then the device is adjusted using a special bolt.

How to check a gas pressure gauge

In general, the test consists only of comparing the data of the pressure gauge being tested with the readings of the control device or calculating the current gas pressure, then measuring it using a pressure gauge and comparing the data. To do this, you only need a control pressure gauge and a thermometer. If we describe this procedure in more detail, it looks like this:

• install the pressure gauge sensor into the container through a special fitting;
• when the pressure value is recorded, remove the pressure gauge and install a control device in its place;
• After comparing the readings of the two instruments, check the accuracy of the instrument readings;
• if the instrument readings do not coincide with the reference pressure gauge, it is necessary to adjust it so that under the same operating conditions the instruments show the same pressure values;
• there are adjusting bolts on the pressure gauge body, with the help of which adjustments need to be made;
• with an electronic analogue the actions are the same, only you need to take into account that this device has inertia, so the readings must be held for 8 to 10 s.

If there is no reference device, you must first calculate the working pressure using the formula P2=T2•P1/T1:

• this will require a vessel of a volume that is known or can be measured, containing air at normal atmospheric pressure and room temperature;
• the vessel is hermetically sealed and gradually heated;
• then the pressure inside the vessel is simply calculated using the formula, where T1 and T2 are the initial and final air temperatures in the vessel, and P1 is the atmospheric pressure.
• if the instrument readings do not coincide with the calculation, then it is necessary to adjust it to the data obtained during the calculation.

Requirements for calibration of pressure gauges

To verify the basic parameters of the measuring device, attention should be paid to the basic requirements that apply to the procedure in question. These include the following points:

1. Before the actual inspection, you should provide documents that confirm that you have completed this procedure previously. The results that were obtained earlier may also be required during the next verification. Some companies do not carry out the procedure in question if the appropriate document is not available.
2. If the device is part of a critical mechanism, then it must have a seal. Otherwise, the mechanism cannot be used for its intended purpose.
3. Depending on the pressure in the system, the most suitable equipment is selected. The most important parameters are the measurement range and the scope of application of the device.
4. The data from the device used must be easily readable. For this purpose, the most optimal working conditions are selected.
5. The installation of a pressure gauge must be carried out exclusively in compliance with all safety measures. A fairly common mistake is reducing the strength of the connection. If high pressure is applied, a leak may occur, which will reduce the pressure in the system.

All established standards are taken into account by the specialist who verifies the device. If the requirement is not taken into account, the condition of the structure cannot be verified with high accuracy.

Workplace for checking SI biopotentials

Time limits for checking pressure gauges

Most attention is paid to deadlines. The purpose of calibration is to increase the accuracy of the readings taken. Among the features we note the following points:

1. When submitting a pressure gauge for verification, you need to be prepared for the fact that it will be in the company for 14 working days. Some companies complete the task much faster. Do not forget that verification requires quite a lot of time, which eliminates the possibility of making an error.
2. For reference devices, the period is reduced to 7 working days. When contacting a company that provides the services in question, you can find out how long the work will be completed.
3. You can reduce the timeframe by submitting documents in advance. Many companies allow you to call and order verification, as well as send documents electronically for their preliminary verification.
4. The measuring device can only be removed from the device by calling a specialist who provides the appropriate services. Do not forget that making mistakes at the time of installation can compromise the integrity of the highway.
5. The tests carried out must last for a certain period. Manufacturers often add instructions for using calibration devices to the package.

How is the credential stamp deciphered?

Stamp on the pressure gauge explanation

Pressure gauges with verification in the catalogue.
According to Law No. 102 of June 26, 2008 “On Ensuring the Uniformity of Measurements,” measuring instruments that fall within the scope of state regulation are subject to initial and periodic verification. Verification of measuring instruments is carried out by CSM laboratories (center for standardization and metrology) or other accredited organizations. Based on the verification results, the measuring instrument is recognized as suitable or unsuitable. Suitable measuring instruments are certified by a verification mark in the verification certificate, in the passport or on the measuring device itself. An example of a verification certificate is given below. The verification certificate bears the personal stamp of the verifier. The verification certificate issued by the State Center for Standardization and Metrology (TSSM) is additionally confirmed by a sticker with a hologram. By the number on the sticker you can obtain information about the verified measuring instrument. The validity period of the verification is indicated in the verification certificate for the device and the verification interval is indicated in the type approval certificate. The verification certificate indicates: document number, verification date, name of the organization, name and number of the device, verification method, environmental conditions during verification, name and number of the standard, conclusion of suitability, verification stamp, details of the performer.

For pressure gauges, a verification mark is applied to the device body on the front or back surface. Before a new verification, the old mark is erased.

The verification mark is deciphered:

1. Gosstandart sign

2. Quarter or month of verification

3. Last two digits of the verification year

4. Metrological service code

5. Individual sign of the verifier

Verification stamp of the state metrological service and scientific metrological institute.

The verification mark of a commercial organization for new devices and after repair and operation.

An example of a verification terminal in the instrument passport E6-31 megohmmeter, the verification date and quarter are indicated in the stamp. Some passports indicate the date of verification, but the stamp does not indicate the quarter or month.

If it is not possible to verify the device or if the device is not in the State Register of Measuring Instruments, the device is calibrated. An example of a calibration certificate is below.

The Ukrainian verification mark with the trident symbol as in the image below is not valid on the territory of the Russian Federation.

Conventional codes of verification marks assigned by Rosstandart accredited for performing work on verification of measuring instruments

Verification is, in essence, confirmation of product quality and indicates compliance of the product with current standards. It consists of a series of tests to determine the metrological characteristics of the measuring instrument. When verification is necessary, which instrument is subject to verification, who has the right to carry it out and how the verification results are correctly documented, you will learn from this article.

The information in the article relates to the verification of instruments for measuring geometric quantities (since we specialize in this type of product), but for the most part it is also true for other measuring instruments.

How is a measuring instrument verified?

To carry out the verification process, the measuring instrument is transferred to a special organization that has a license to carry out such work - this can be a regional center for standardization and metrology (for example, the Chelyabinsk Center for Materials and Measures), or an independent accredited laboratory. Such laboratories mainly exist at tool factories, large industrial enterprises and institutes. During verification work, the metrologist checks the compliance of the instrument with the standards in force for it. If the test outcome is positive, a document is drawn up confirming the quality of the instrument; if the test is negative, a conclusion about unsuitability is issued.

Which tool can you trust?

A measuring instrument has one necessary condition for verification - it must have a type approval certificate. This document indicates that this type of measuring instrument was successfully tested by the Federal Agency for Technical Regulation and Metrology, as a result of which the quality standards in force for it were approved and the verification methodology was established.

Sample type approval certificate

After receiving the certificate, the instrument is automatically entered into a special database - the State Register of Measuring Instruments (State Register). The presence of a product in this database means that it is approved for use in Russia and can be trusted.

Let's say you need a vernier caliper. By going to the Rosstandart website in the State Register database, you can make sure that the calipers are produced by the Chelyabinsk Tool Plant, Stavropol Tool Plant, etc. have a type approval certificate and can be verified accordingly. If the manufacturer is not in the database, such a tool cannot be trusted (but it can be calibrated; more about this in the next article).

Who can carry out verification?

The verification organization must have valid accreditation to carry out work on verification of measuring instruments, and the instrument being verified is within its scope of accreditation. For example, a laboratory may be accredited to test angles up to 400 mm in length, but then it will not be possible to test longer models.

Sample accreditation certificate

After successfully completing accreditation, the organization is assigned a conditional verifier code, consisting of alphabetic characters (from one to three letters, more details below). This code is individual, and it must be present in the verification document.

The registration number of the accreditation certificate must be indicated in the verification certificate. You can find an organization by its code in the official Rosstandart database.

When is verification needed?

According to Federal Law No. 102 of June 26, 2008, measuring instruments included in the scope of state regulation of ensuring the uniformity of measurements (GROEI) are subject to mandatory verification. Simply put, these are all works that are controlled by the state. This includes the military-industrial complex, healthcare, activities in the field of life safety, trade, geodesy, hydrometeorology, etc. If the tool is used in work that is not within the scope of GROEI, its verification is not required. But of course, you can still do it to confirm the accuracy of the measurements (calibration is also suitable for this).

It is also worth noting that the measuring instrument is not subject to mandatory confirmation of conformity. The manufacturer is not obliged to enter it into the State Register, that is, all work is performed voluntarily. But all more or less serious manufacturers are still trying to obtain certification, at least for the most popular models, since this significantly expands the scope of their application.

What types of verifications exist?

The main two types of verification are primary, when a new tool is verified, just released from production (or after repair), and periodic, carried out during operation or storage of the tool.

Initial verification upon release from production is often carried out by laboratories located directly at the manufacturing enterprises (there are such laboratories at the Chelyabinsk, Kirov, Stavropol and other tool factories). All of them undergo licensing and accreditation for verification rights, and, in fact, are considered independent.

Periodic verification is ordered mainly when the validity period of the previous verification expires. The period of time during which verification is valid is different for each type of product and is established at the time of receipt of the certificate (entry into the State Register). The period can vary from 6 months to 5 years. For a measuring instrument this interval is usually 1 year.

In addition to the two above, there are the following verifications: extraordinary, inspection, expert.

How is verification confirmed?

The document confirming the verification must contain a verification stamp. This is the name of the special seal assigned to the verifier after successful accreditation. The date of verification and information about the verifier are encrypted in the stamp using alphabetic and numeric symbols.

Sample verification certificate

If the product successfully passes the tests, a verification certificate is most often issued, which reflects data about the tool and indicates what standards it meets, the verification date and its validity period are required. In addition, during the initial verification, information about its completion can be entered directly into the product passport. Legally, such a document is no different from a separate certificate. The main thing is the presence of a verification mark and signature of the verifier.

Sample verification in passport

Recently, special stickers with holographic protection, pasted into the verification certificate, have become widespread. They contain a barcode that encrypts all the main aspects of the document. The use of these stickers allows you to further protect certificates from counterfeiting and automate the identification of measuring instruments. Simultaneous application of a verification mark and a sticker is allowed, but its independent use is quite sufficient.

Example of using a verification sticker

Deciphering verification marks.

The verification mark can be of the following form:

• round - for regional centers of standardization and metrology (state bodies HMS and SSMC);
• rectangular - for legal metrological services. persons during initial verification;
• square - for legal metrological services. persons during periodic verification (it is worth noting that a square stamp can also be placed during initial verification).

Deciphering verification marks

Verification stamps must contain the following information:

• sign of the federal executive body in the field of metrology - Gosstandart of Russia;
• conditional code of the State Migration Service (two letters of the Russian alphabet), State Scientific and Technical Center (one letter of the Russian alphabet) or the metrological service of a legal entity (three letters of the Russian alphabet). That is, an individual code assigned directly to the verification organization is indicated. You can find an organization by its code, or vice versa, in the Rosstandart database;
• the last two digits of the year of application of the verification mark;
• individual sign of the verifier. Designated by one of the letters taken from the Russian, Latin or Greek alphabets.

In addition, the month or quarter of verification can also be entered in the stamp field. The month of the year is indicated by Arabic numerals (1, 2, 3...). The quarter of the year is designated by Roman (I, II, III, IV).

When is verification carried out?

When submitting an instrument for verification, you need to take into account that this process is not very fast. The time frame may vary from 2 weeks to 2 months. The average duration is around a month. Basically, this period depends on the workload of the auditing organization. If you are lucky and you find yourself in a quiet moment, they will issue you quickly; if not, you will have to wait. In theory, there is an urgent verification, when for an additional payment you are required to complete the work in a week or two, but in practice this does not always work - the verifier either refuses to place an order with urgency, realizing that he will not have time, or the deadlines are simply not met.

For the convenience of our clients, we try to maintain stock availability of certified instruments. In addition, tools produced by the Kirov (KRIN) and Stavropol (STIZ) tool factories are initially supplied with initial factory verification and do not require additional quality confirmation. But of course, not all orders for certified instruments can be satisfied from availability, so expectations are inevitable.

Where can I order verification?

The simplest thing is to contact the regional center of the FMC. They are in all major cities and regional centers. But the main drawback of these organizations is their heavy workload (measuring instruments are brought to them from all over the region, since some types of metrological work can only be performed by government agencies), and as a result, long deadlines. So sometimes it’s worth looking for commercial organizations closest to you that have certified laboratories for verification.

We work with the following verification organizations:

• Federal Budgetary Institution "Chelyabinsk Center for Medicine";
• Federal Budgetary Institution "Kurgan Center for Medical Care";
• TsIL LLC NPP "Chelyabinsk Tool Plant";
• Metrological service of the Federal State Unitary Enterprise "RFNC-VNIITF named after. academic E.I. Zababakhina", Snezhinsk.

We can recommend these verifiers as professionals in their field, working according to modern metrological standards and accredited in a wide range of types of measuring instruments.

Please note that in the “Materials” section of our website you can find quality standards (GOST) and verification methods (MI) for measuring instruments.

• You can always get additional advice on verification of measuring instruments by calling +7 (351) 790-77-48, writing by e-mail, or asking a question through the feedback form.

>Verification and calibration

Is it necessary to check pressure gauges?

The initial verification of the device is carried out to determine the nominal pressure indicator. In the future, control eliminates the possibility of a decrease in accuracy.

Periodic checking of the pressure gauge is required in order to eliminate the possibility of its failure.

Some systems cannot be operated without the use of a pressure gauge.

If the procedure in question is not carried out in a timely manner, you may encounter the following problems:

1. Error when taking measurements. In some cases, a slight error does not reduce the efficiency of the compressor; in others, pressure accuracy is important.
2. The service life of the pressure gauge is significantly reduced. Some damage to the mechanism during long-term use can lead to rapid wear. The cost of high-precision pressure gauges is very high.
3. There is a possibility of a medium leak, which will cause a decrease in pressure in the system.

In conclusion, we note that if it is necessary to verify the compressor measuring instrument, you can carry out similar work yourself. To do this, you can purchase a special device in a specialized store. Other mechanisms that have higher requirements must be checked exclusively by a specialist. After the procedure, a filling must be placed.

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Answer

The site manager is not right about everything.

Federal Law of June 26, 2008 No. 102-FZ “On Ensuring the Uniformity of Measurements”, extract:

1. The objectives of this Federal Law are:

2) protection of the rights and legitimate interests of citizens

, society and the state from
the negative consequences of unreliable measurement results
;

3) meeting the needs of citizens

, society and the state in
obtaining objective, reliable and comparable measurement results
used
to protect the life and health of citizens
, protect the environment, flora and fauna, ensure the defense and security of the state, including economic security;

3. The scope of state regulation of ensuring the uniformity of measurements extends to measurements for which, for the purposes provided for in Part 1 of this article, mandatory metrological requirements are established and which are carried out when:

5) carrying out work to ensure safe conditions and labor protection

;

That is, when reading these paragraphs, it becomes clear that this law applies to devices whose inaccurate measurements can lead to violations of work safety (including welding) and damage to the health of workers.

That is why pressure gauges are sold by attorneys, and also requirements for periodic verification of pressure gauges have been introduced into a number of FNP and Labor Safety Rules.

When you buy pressure gauges, you are already buying certified

pressure gauges.

The stamp on the pressure gauge you buy must contain information (mark) about the verification date.

It can be applied:

- directly to the pressure gauge,

- or for a certificate of verification

- or in the pressure gauge passport.

You can operate pressure gauges for the period specified in the operating documentation.

If your organization
is not a hazardous production facility
, then you need to check
them during operation
only if this is indicated in the operational documentation. In this case, the deadlines are also indicated there. Those. In this part, the site manager is right.

But, during operation, during the stated shelf life, it is necessary to check any types

pressure gauges, if they are installed on equipment subject to any FNP in the field of industrial safety, or if the requirements for such verification are established by the relevant labor protection rules or operating instructions.

− clause 63 of the Order of the Ministry of Labor of Russia dated December 23, 2014 No. 1101n “On approval of the Rules for labor protection when performing electric welding and gas welding work”:

63. When performing gas welding work, it is prohibited:

3) install unsealed pressure gauges on the reducers of gas cylinders, as well as pressure gauges that have:

— there is no state trustee stamp

or a stamp with a mark
of annual
verification;

— there is no red line on the dial corresponding to the maximum operating pressure (it is not allowed to put a red line on the glass of the pressure gauge; instead of the red line on the dial of the pressure gauge, it is allowed to attach to the pressure gauge body a plate of material of sufficient strength, painted red and tightly adjacent to the glass of the pressure gauge);

— when the pressure gauge is turned off, the needle does not return to the zero mark of the scale by an amount exceeding half the permissible error for a given pressure gauge;

— the verification period has expired;

— the glass of the pressure gauge is broken or there are other damages that may affect the accuracy of its readings.

Frequency of checking pressure gauges

A pressure gauge is a device that measures pressure in a device, container, or pipeline. There are several types:

Spiral pressure gauges consist of a metal spiral that is connected by a transmitting element connected to a pointer on a dial. The higher the pressure, the more the spiral unwinds and pulls the arrow along with it. Which is reflected in an increase in pressure readings on the instrument scale.

The diaphragm pressure gauge provides readings due to a clamped flat plate, which is connected to the transmitting element. When exposed to pressure, the membrane bends and the transmitting element presses on the dial arrow. This is how blood pressure increases.

To check the compliance of the accuracy parameters of the meter declared by the manufacturer and to monitor the metrological serviceability of the device, without which the pressure gauge cannot be used in areas falling under GROEI (state regulation for ensuring the uniformity of measurements), and also to ensure that the device serves the established period and operation is safe, it should be periodically carried out checking the pressure gauge. The rules set by the state state that, depending on the technical characteristics of the device and the manufacturer's instructions, the reconciliation period ranges from 12 months to 5 years.

Regular inspection of the device after a year was considered the most common, but now manufacturers are improving the characteristics of the equipment, and devices with a verification period of 2 years are increasingly found. It is worth remembering that the pressure gauge must undergo inspection and verification after a certain period from the date of production, and not from the moment it is put into operation.

The service life of a pressure gauge is set by manufacturers; on average, it is 8-10 years. It is necessary to keep a log of pressure gauge checks in order to check the device on time.

Self-check of the pressure gauge

If your task is not to document the timing of checking the pressure gauge, but to verify its operation, then you can check the pressure gauge yourself. For this you will need a control device.

Checking the serviceability of the pressure gauge:

• Install a pressure gauge into the container to check. Wait until the arrow stops.
• Remove the device. Install a control pressure gauge there.
• Compare the received readings.
• If they do not match, the pressure gauge must be repaired or replaced.

The frequency of checking pressure gauges in households and enterprises not from areas falling under GROEI should also be established in accordance with the technical data sheet of the devices.

Methodology for checking pressure gauges

To check the operation of the measuring device, you should contact specialists who have received accreditation of a sufficient level (in accordance with the type of pressure gauge you have); these organizations are registered in the state register. The service must be provided by trained employees. Verification is also carried out by state metrological control bodies. You will then be provided with a protocol, which should be kept until your next follow-up visit.

The pressure gauge can be checked in several ways using:

• metrological stand;
• hydraulic press;
• calibrator.

Checking the pressure gauge using a metrological stand allows you to check the pressure at the installed control points with minimal error. The process is carried out using two pressure standards and comparing their indicators. The device creates special pressure using a pump. Deadweight piston devices are used more often.

Verification using a hydraulic press takes place on a device that includes several weights, a standard meter and a device that sets the pressure, a press. A calibrated pressure gauge is installed between the parts of the apparatus. The final data of the pressure gauge under study must coincide at the control points of the scale. These devices are highly accurate and allow a minimum error (0.04 psi).

Procedure

If, as a result of checking pressure gauges, a Verification Certificate or a device verification protocol is required, it can only be carried out by a certified specialist. The organization providing services must be included in Rosreestr.

Verification of pressure gauges is carried out in the laboratory under normal environmental conditions using certified metrological equipment in compliance with the requirements of the Verification Methodology.

The procedure for checking the pressure gauge:

1. Appearance.
2. Testing: The pressure gauge to be verified is installed on the equipment, maximum pressure is applied, the pressure gauge is maintained at maximum pressure, then the pressure is gradually reduced to 0.
3. Control of readings: The readings of the standard and the pressure gauge being verified are compared.
4. Based on the procedures performed, a conclusion is drawn about the suitability or unsuitability of the application.

Checking pressure gauges - rules

To accurately examine a measuring device, it is necessary to follow some rules for calibrating pressure gauges:

• inspect for external defects (for example, broken glass);
• it is necessary to create conditions close to normal when carrying out verification (atmospheric pressure 760 mm Hg, air humidity up to 65%, room temperature 20◦ C);
• set the dial hand to zero;
• compare the readings of the reference device and the one being tested.

The last two points, if it is impossible to set the arrow to zero and differences appear between the reference and the device being tested, should be adjusted using bolts. If the nominal parameters are not set, it may be easier to replace the pressure gauge with a new one, given the low cost of the device.

How verification is carried out

The readings of pressure meters must be checked by state metrological control authorities. Devices can also be verified by specialized organizations that have appropriate accreditation.

Verification is performed in the following order:

A control inspection of the device is carried out for the presence of external mechanical defects.

Standard conditions are created for verification: atmospheric pressure - about 760 mm Hg, air humidity - about 65%, air temperature - about 20 °C.

The dial arrow is set to 0.

Using special equipment, a reference pressure is created, which is measured by the calibrated and reference pressure gauges, after which their readings are compared.

To carry out verification, types of equipment such as a special metrological pressure gauge stand, a hydraulic press and a calibrator can be used. In this case, the use of a calibrator is allowed when checking pressure gauges for which state requirements for metrological control are not provided.

Source: grom.ru

Requirements for calibration of pressure gauges

To verify pressure meters you must:

• provide documents confirming the completion of the previous verification;
• presence of a seal, stamp;
• use devices of class 1.5 or 2.5 (depending on operating pressure);
• the pressure gauge data must be clearly readable by the person conducting the verification (if the pressure gauge is installed at a height of 2 m, then the diameter of the dial must be at least 100 mm, if at a height of 3 m - 160 mm);
• The pressure gauge must be installed in compliance with all safety rules (if it is a gas cylinder measuring device, then it should be installed in a well-ventilated, separate room, protected from unexpected fire).
• The owner, in addition to annual verification, must record data in a log when using a reference device.

Do not operate devices that have not been verified on time.

Verification stamps

Verification mark - a print, sticker or otherwise produced conventional image applied to the SI and (or) to the verification certificate or passport (form).

Verification marks are used by the bodies of the State Metrological Service, State Scientific Metrological Centers of Rosstandart of Russia, as well as metrological services of legal entities accredited for the right to verify measuring instruments.

The form and procedure for applying verification marks are regulated by Order of the Ministry of Industry and Trade of the Russian Federation dated July 2, 2015 N 1815 “On approval of the procedure for verification of measuring instruments, requirements for the verification mark and the content of the verification certificate.”

Methods and order of application

The surface of the measuring instrument intended for placing verification marks is determined in accordance with the description of the type of this measuring instrument. Depending on the design of the measuring instrument, its operating conditions and taking into account the preservation of the image during the verification interval, the rules provide for the following methods of applying the verification mark:

• shock;
• pressure on the filling or special mastic;
• gluing;
• electrographic;
• electrochemical;
• sandblasting;
• burning;
• other methods that do not contradict the above conditions.

The application of the verification mark is carried out by verification work performers acting within the framework of their legislative powers, namely:

• state scientific metrological institutes;
• regional metrology centers;
• legal entities;
• individual entrepreneurs.

Contents of the verification mark

In accordance with the established rules, the verification mark must contain the following information:

• sign of the Federal Agency for Technical Regulation and Metrology;
• code of the state metrological body, legal entity or individual entrepreneur;
• the last two digits of the year of verification;
• individual code of a specific verifier.

In addition, methods for verifying some measuring instruments may provide for the placement in the field of the sign of additional information about the timing of its application, depending on the duration of the MPI:

• month (indicated by Arabic numerals) – for MPI up to 3 years, inclusive;
• quarter (indicated by Roman numerals) – for MPI over 3 and up to 10 years, inclusive.

For verification marks in the form of stickers, the rules establish the following content:

• the “RST” logo (in the upper part of the field) in the form of a hologram containing both visible and hidden images, readable using special equipment;
• barcode;
• verification date.

Note: a barcode allows you to automate accounting and statistical operations for specific SI, and therefore it is recommended to use it always, if technically possible. The numbering of signs containing barcodes is the responsibility of the Federal Agency for Technical Regulation and Metrology.

The code of the organization (person) performing verification work is an alphabetic code consisting of capital letters of the Russian alphabet:

• one (A, B, C, etc.) – for state scientific metrological institutes;
• two (AB, AB, etc.) - for state regional metrology centers;
• three (AAV, AAG, etc.) - for legal entities and individual entrepreneurs.

The individual sign of a particular verifier is a lowercase letter of the Russian, Latin or Greek alphabet. If it is impossible to assign an individual mark to each verifier in the specified way, the rules allow the following methods:

• placement of the letter in angular positions of 90°, 180° and 270°;
• creation of units with a number of verifiers of no more than 256 people each, assigning each unit an individual code and indicating the latter verification sign in the information field.

Shape and dimensions of verification marks

The legislation provides for the following forms and sizes of verification marks:

• round, with recommended diameters of 4, 6, 8, 10, 18, 24 mm - for state metrological authorities;
• square, with sides equal to the above diameters - for legal entities and individual entrepreneurs; applied when checking newly manufactured measuring instruments;
• rectangular, with a length to width ratio of 1.5: 1, with the latter corresponding to the specified size range - for the same categories of performers; are used when checking used and restored measuring instruments.

Verification marks in the form of stickers are made opaque, self-adhesive, in the form of a rectangle with sides 10x50 mm, with a thickness of no more than 0.05 mm.

The size of the mark is selected based on the availability of specific devices, the size of the SI surface intended for it, the method of application, as well as the conditions for readability and preservation of the image during the MPI.

Forms of verification marks (rubber version):

Imprints of verification marks of various designs:

Procedure for storing verification stamps

A specially appointed person from among the employees of the state metrological organization, legal entity or individual entrepreneur who verifies measuring instruments in the manner prescribed by law is responsible for the storage, recording and issuance of verification stamps.

Information regarding the issuance and receipt of verification marks by persons directly performing verification work is reflected in a special journal of the established form. The form of the journal is given in Appendix 4 to the Procedure for verification of measuring instruments, requirements for the verification mark and the contents of the verification certificate, approved by Order of the Ministry of Industry and Trade of Russia dated July 2, 2015 N 1815.

Verification marks are assigned to specific verifiers, without the right to transfer them.

An imprint is made from each stamp, and when using stickers, a special copy is allocated for storage for 2 MPI from the moment of application to the SI and/or verification certificate.

Upon expiration of the terms of use of the brand, or for other reasons that do not allow its further use, the brand is destroyed, which is certified by an act of the established form.

Tags: stamp verification

Time limits for checking pressure gauges

If you have submitted a pressure gauge for verification, be prepared for the fact that it will be returned to you only after 14 working days. For reference devices, reconciliation is carried out within 7 working days. You must submit or fill out an application in advance to ensure verification is completed on time. Also, if you are going to bring a device that has been sealed or branded for verification, you should call the specialist who performed the services and remove the measuring device. If you can call a specialist to the site to calibrate the pressure gauge, it will take a whole working day.