Standard requirements for leak checks of stationary refrigeration and air-conditioning equipment and heat pumps containing certain fluorinated greenhouse gases were set out in Commission Regulation (EC) No 1516/2007 of 19 December 2007.

Our refrigeration equipment inspection offer Fill in the form and commission inspection of your equipment!

Standard requirements for leak checks of stationary refrigeration and air-conditioning equipment and heat pumps containing certain fluorinated greenhouse gases were set out in Commission Regulation (EC) No 1516/2007 of 19 December 2007. That document distinguishes the following types of leak checks:
– periodic
– after elimination of a leak
– of newly installed equipment
Leak checks of equipment filled with fluorinated greenhouse gases may be carried out only by personnel holding a so-called F-gas certificate.

PERIODIC LEAK CHECKS
The criterion qualifying equipment for mandatory inspection is the quantity of refrigerant contained in the system – the so-called charge – converted for F-gases into an equivalent quantity of carbon dioxide.
Table 1. Criteria for mandatory leak checks according to Regulation (EU) No 517/2014:

Charge of fluorinated greenhouse gases Minimum frequency of conducting leak checks	Stationary refrigeration and air-conditioning equipment			Refrigerated trucks and trailers
	≥ 5 t CO₂ equivalent (hermetically sealed equipment ≥ 10 t CO2 equivalent)	≥ 50 t CO₂ equivalent	≥ 500 t CO₂ equivalent	≥ 5 t CO₂ equivalent (hermetically sealed equipment ≥ 10 t CO₂ equivalent)`
Without a properly functioning, appropriate leak detection system	12 months	6 months	mandatory leak detection system	12 months
With a properly functioning, appropriate leak detection system*	24 months	12 months	6 months	24 months

*The leak detection system shall be checked every 12 months to ensure its proper functioning

Periodic leak checks may be carried out using:
– indirect measurement methods
– direct measurement methods
Indirect measurement methods are used when loss of tightness occurs slowly and when equipment is located in well-ventilated places. To detect a leak, authorised personnel carry out visual and manual inspections of the equipment and analyse one or more of the following parameters:

pressure;
temperature;
compressor current draw;
volume of refrigerant topped up – assessment based on a sight glass

Direct measurement methods are used to determine the exact location of a leak.
These measurements are made using:
– electronic leak detectors (gas-detecting devices)
– foaming agents (soapy solutions, foams)
– fluorescent dyes and UV lamps

Electronic leak detectors (gas-detecting devices). The most widespread devices currently on the market are:
– with a cold-cathode diode sensor, with sensitivities from 2 g/year. These devices are most often adapted to detecting the entire group of CFC, HCFC, HFC refrigerants and SF6 and their mixtures (they do not detect hydrocarbons). They usually have adjustable sensitivity.
– with a “hot pentode” type sensor – they detect leaks from 3 g/year – characterised by greater repeatability of indications and longer trouble-free operation than detectors with diode sensors; they detect all halogen gases CFC, HCFC, HFC. Before use they require warm-up of the sensor.
– with a semiconductor sensor – without a suction pump, convective, with adjustable sensitivities from 10 to 30% LEL (lower explosive limit). Used among other things to detect leaks of methane, ammonia, isobutane, propane, hydrogen.
In accordance with applicable regulations, electronic leak detectors must have a minimum sensitivity of 5 g/year and must be checked once every 12 months.

Leak detection using foaming agents is possible for systems under pressure. Leak location is carried out on a non-operating system. Many different products are available on the market; it is recommended to use those characterised by a stable, lasting foam.

Leak detection using fluorescent dyes and a UV lamp may be used when the equipment manufacturer permits the use of dyes in the refrigeration system. This system allows precise and rapid location of the leak point. The kit includes a UV lamp, a fluorescent dye appropriately selected for the type of refrigerant and oil in the system being checked, and special glasses.

Ultrasonic leak detectors operate on the basis of ultrasonic technology. Locating the leak point consists in detecting ultrasound emission by gas escaping at the leak point. They enable precise location of leaks. The type of gas detected is not important; the pressure difference is of fundamental importance. They are very durable and hard to damage; interference with their indications is caused by ultrasound emission from other sources.

Operators of refrigeration equipment containing fluorinated greenhouse gases in quantities of 500 tonnes of CO2 equivalent or more are obliged to equip them with a leak detection system. Correct operation of these systems should be checked at least once every 12 months
Stationary leak monitoring systems are intended to monitor refrigerant leakage in a given zone and, if detected, to enable activation of an external alarm notifying the operator.

LEAK CHECKS AFTER ELIMINATION OF A LEAK AND FOR NEWLY INSTALLED EQUIPMENT

Pressure leak test using deoxidised nitrogen is the most widespread and most frequently used form of leak check, carried out for newly installed equipment and for equipment in service after elimination of a leak. This test provides information that a leak has occurred but does not indicate the specific location. During a pressure leak test, temperature should be controlled in addition to pressure, because temperature changes affect the value of pressure readings.

The following equipment is required for its correct performance:

nitrogen cylinder
cylinder pressure regulator
pressure gauge of appropriate range
thermometer
connection hoses,
watch

Parameters of the pressure leak test (including test durations and pressures) are described in standards: PN-EN 378-2:2017-03, PN-EN 14276-1+A1:2011, PN-EN 14276-2+A1:2011

Leak detection system using tracer gases (helium or hydrogen detector)

consists in introducing a mixture of nitrogen with an admixture of tracer gas (helium or hydrogen) into the component or system being checked. Due to its properties, tracer gas has a much higher ability than nitrogen to penetrate even the smallest leaks, making their location with a tracer gas locator easier. The method is very accurate; it is used by manufacturers in series production, e.g. of vessels, and by personnel servicing equipment.
Leak test by immersion in a water bath
The method, like the pressure leak test, consists in subjecting the component or equipment under test to a test pressure, with the difference that during the test the equipment under test is immersed in a water bath, often illuminated. If a leak occurs, escaping gas bubbles are observed. The method is suitable for small equipment or components and allows precise location of the leak point
Vacuum leak test consists in creating as deep a vacuum as possible in the system using a vacuum pump and monitoring maintenance of the vacuum obtained in the system using a vacuum gauge. To obtain vacuum more quickly it is recommended to use more than one service connection in the system. A system leak during a vacuum test is manifested by a gradual rise in pressure. In the case of larger leaks, despite operation of the vacuum pump it is not possible to obtain vacuum in the system under test. The vacuum method is not very accurate because of the small pressure difference that can be obtained. It is recommended to obtain a vacuum lower than 270 Pa. In addition, evaporation of water in wet systems, or residual refrigerant from oil, significantly prolongs the test or gives false results.

REQUIREMENTS FOR INSTRUMENTS USED TO DETECT LEAKS AND DIAGNOSE REFRIGERATION SYSTEMS

Leak detection and repair of refrigeration equipment requires appropriate measuring equipment enabling proper diagnostics.

Calibration of instruments is carried out by comparing the indications of the instrument being calibrated directly with national measurement units or with the indications of an instrument that is a reference standard.

It is recommended that all measuring instruments whose indications serve as the basis for:

drawing up inspection, acceptance or commissioning reports,
calculations whose results provide information on capacities,
control measurements performed during periodic leak checks
issuing opinions, expert reports, etc.
measurements affecting human health or life
manufacture of food, pharmaceutical and chemical products
operation of equipment ensuring the required parameters for storage and transport of medicines and food,
control and monitoring of parameters in refrigerators, cold stores, freezers as well as incubators, dryers, autoclaves, sterilisers, ovens, climate chambers,
control of processes and the environment in the food, pharmaceutical and cosmetics industries,
systems for monitoring temperature, humidity and air velocity parameters in cold stores, freezers, warehouses

monitoring temperature in special means of transport for perishable food products and pharmaceuticals
be periodically calibrated, i.e. measurement traceability must be maintained for them. Periodic calibration of measuring instruments provides confidence in the measured parameters of the refrigeration system and confirms the reliability of the measurements performed. It contributes significantly to raising the quality and efficiency of the services provided. We invite you to use the services of our Laboratory for checking and calibrating electronic leak detectors, thermometers, pressure gauges and multimeters – all those who perform service work and pressure tests in the refrigeration and air-conditioning industry. We also provide services for the transport industry, among other things in the certification of insulated means of transport and checking of thermographs used to record temperatures during transport of perishable articles and medicines, and we perform periodic leak checks of refrigeration systems.

Checking of electronic leak detectors

In accordance with the requirements of the F-gas Act, an electronic leak detector must be checked once every 12 months.

Leak checks and measuring instruments in refrigeration We perform leak detector checks to confirm fulfilment of the requirement for minimum sensitivity of 5 g/year

Checking of thermometers

Leak checks and measuring instruments in refrigeration We check thermometers used in refrigeration in the temperature range from −30 to +80°C. Thermometers are checked on a calibration stand and a certificate is issued containing correct (reference) values, values obtained by the instrument under check, and errors.

In accordance with the requirements of the F-Gas Act, a thermometer with a range of −20 to +150°C and accuracy of ±1°C must be held.

Calibration of analogue and electronic refrigeration pressure gauges

Leak checks and measuring instruments in refrigeration We calibrate pressure gauges used for pressure leak tests using inert gas as well as refrigeration pressure gauges (analogue and digital) used for servicing and operation of equipment. We confirm correct operation in the range 0…60 bar

Calibration of multimeters for measuring electrical parameters of refrigeration and air-conditioning systems

Leak checks and measuring instruments in refrigeration We calibrate multimeters (clamp, conventional, analogue and digital) in the current and voltage measurement ranges.

As standard we perform calibration at 5 measurement points for each value (current, voltage, power), and calibration results are presented on a Certificate together with errors.

Calibration is performed on a reference calibrator.

Checking of thermographs

Leak checks and measuring instruments in refrigeration As a result of the check the client receives a certificate confirming that the instrument meets the requirements of PN-EN 13486:2004