Technical means for servicing of refrigeration systems

Minicharging stations of REFCO company(Switzerland). This light portable equipment is designed for vacuumization and charging of refrigerants of CFC, HCFC and HFC groups with temperature scales for R12, R22 and R502 or R134a, R404A. The station is provided with two-stage vacuum pump, built-in safety valve, auxiliary mounting arrangements with slide valves (high-vacuum - dense), pressure gages on the side of suction and charging, electric motor (220...240 В, 50 Hz), charging cylinders. Holding capacity of the cylinder for different versions in the station is given below.

Vacuum-charging stations 10505, 10605, 10705 и 10805. developed for vacuumization and charging of hermetic refrigeration compressors operating on R12, R22, R502 and R134a. They are used first of all during technical maintenance of refrigeration facilities. Main advantages of these stations are their small mass, high productivity of the pump, simpleness in operation.

Station (see the table) are equipped with pressure gages from the side of charging and suction filled with glycerine, heated by charging cylinder; three charging hoses for vacuumization and charging of the facility without substitution of hoses. Stations are supplied in a set with protection glasses and one capacity with oil for vacuum pump.

Portable station 10805-RD-4 for vacuumization and charging of the refrigeration system with the refrigerant: 1 - vacuum-pump; 2 - gas-ballasting valve; 3, 12 - safety valves; 4, 8, 17, 18, 21 - valves; 5 - vacum unit; 6 - vacuum indicator; 7 - handle; 9 - pressure-vacuum gage; 10 - sight glass; 11, 13 - pressure gages; 14 - return valve; 15 - cylinder for refrigerant; 16 - cykinder scale; 19, 22 - pipe sockets; 20 - frame; 23, 24 - tumblers; 25 - electrical panel.

10805-RD-4 station (see the figure) consists of the following elements mounted on the frame: two-stage vacuum pump; cylinder with rotary scale; pressure gage with temperature scales for R12, R22, R502; safety valve and built-in electric heater; pressure-gage unit with pressure gage and pressure-vacuum gage (having scales of temperatures and pressures of R12, R22, R502 refrigerants in the state of saturation), sight glass, valves with pipe sockets fro connection of hoses; vacuum unit with pressure-vacuum gage, valve and safety valve; panel wit electric condenser, tumblers for starting of vacuum pump and electric heater of the cylinder and clamp to connect the station with power network.

In order to fill the station cylinder with the refrigerant, they connect the ballon valve with the filter-dehydrator which is connected with pipe socket 22 with a flexible hose. At open valves 4, 8, 18 and 21, vaccum pump is started with tumbler 24 and the cylinder is vacuumized. After reaching residue pressure equal to 5 Pа, having closed valves 4 and 21, vacuum pump is shut. While opening of the ballon valve, as well as valves 8, 17 and 18 of the station, the cylinder is filled with the refrigerant with its level being controlled. To ensure entering of bigger amount of liquid refrigerant into the cylinder, its vapors are released through return valve.

Using flexible hoses of pipe socket, stations are connected with pipe sockets on suction and charging valves of the compressor of the refrigeration facility. Having started vacuum pump of the station with tumbler 24 at open valves 4, 8, 18 and 17, the refrigeration facility is vacuumized till residue pressure 5 Pа. After 1 hour of operation under this residue pressure, vacuum pump is turned off and keep the system in vacuum during 1 hour. Then, having closed valves 8, 17 and 18, they deliver from the station cylinder into the refrigeration facility the dehydrated refrigerant up to reaching of residue pressure 30...50 кPа, violating vacuum at that which prevents recondensation of water vapors and contributes to their complete removal.

In the same way the second vacuumization of the refrigeration facility is performed and again vacuum is violated.

After the third vacuumization, the refrigeration facility is filled with the necessary amount of the refrigerant from the station cylinder. With that aim all the valves except 8, 17 and 18 are closed. When pressures of the refrigerant in the refrigeration facility and in the station cylinder become equal (which will be seen by cessation of the refrigerant circulation through the sight glass), with the help of tumbler 23 they start electric heater built into the station cylinder. As a result, pressure in the cylinder increases and the refrigeration facility continues to be filled with the refrigerant. The amount of the refrigerant entered into the refrigeration facility is determined by the cylinder scale which has an adjusting frame by the refrigerant pressure in the cylinder.

Charging station 11705 of REFCO company. This charging station is installed on two wheel frame. There are possible different constructions depending on the refrigerant being used - R12 or R134a.

Taking into account the fact that for the systems operating on R134a, there's especially important the process of vacuumization, they install only two-stage vacuum pump in the basic set.

Sets of different charging stations of this series is given in the table.

Charging station 10905-S-R134a of REFCO company. Developed for servicing of automobile air-conditioners. For convenience the station has been installed on three-wheel frame. It consists of the following elements: steel frame; two-stage vacuum pump RD-4; charging cylinder for R134a with heating of big capacity withholding capacity of 4 kg; oil-flooded pressure gages with diameter 80 mm with the scale for R134a (presupposed protection from excess pressure); pressure-vacuum gages 19801 with diameter 100 mm with built-in safety valve and arrow; service valves CX-Auto 1/4 of blue and red color; all the necessary charging hoses.

FAST6-R12 station of REFCO company for regeneration, vacuumization and charging. Designed for operation with refrigerants R12, R22 and R502. It consists of hermetic compressor with the sight glass for the oil, oil eliminator, fan, pressure gage, low and high pressure relay, all the necessary service valves. All the equipment is placed in strong aluminum covering and is ready for operation. The station is operating from the current with voltage 220...240 V (50 Hz). Analogous station FAST6-R134a is designed for operation with R134a refrigerant.

Automatic station is simple in operation. There is foreseen the possibility of the refrigerant regeneration with its repeated charging into the refrigeration system. Suction of the refrigerant, its regeneration and vacuumization of the facility occur automatically in the fixed order. Ignition of the lamp on the control panel shows that the first operation is completed. Since all the operations are automatic, the risk of the refrigerant hitting the atmosphere is zero. A mechanic can control occurring operations with the help of built-in pressure gages on the lines of suction and charging.

The facility is produced in two versions (SECUMAT R12 and SECUMAT R134a) depending on the used refrigerant.

Charging station 10854 of REFCO company. Designed for servicing of domestic refrigerators and deep-freezers operating on R600a or R134a. The station consists of the following elements: high-vacuum pump ROYAL-2; electronic weighs with measurement range from 0 to 2000 gm and with measurement unit 1 gm; dial vacuum gage with diameter of 100 mm; pressure-vacuum gage with diameter of 68 mm with temperature scale for R134a; charging valve for R134a; polyamide capillary hose; supporting device for charging of liquid R600a; all the necessary charging hoses, including on especial hose of 5 m length, which according to the requirements of safety engineering, excludes appearing of gaseous R600a into the working zone.

Charging cylinders of REFCO company. Designed for operation with the refrigerants of CFC, HCFC and HFC groups. Charging cylinders (see the figure) have high strength structure which allows in the field conditions of maintenance to ensure their no-failure operation. There exist big cylinders and mini-cylinders; mini-cylinders are approximately half height lower than big cylinders. Designation of charging cylinders with additional letter "H" means that they are provided with electric heater (220...240 V, 50 Hz). Designed for R134a and R404A, charging cylinders, according to safety rules, are not allowed to use for filing of facilities with refrigerants R12, R22, R502 and visa versa.

Charging cylinders are gauged after metric system of measures. In the table there are given technical characteristics of charging cylinders.

Charging hoses. They are supplied with built-in Teflon gaskets, and thanks to them their service life is increased almost ten times more compared to the service life of simple charging hoses completed with neoprene gaskets.

Charging hoses supplies separately have the following length.

Charging hoses supplied in a set (blue, red, yellow) have the following length.

Charging hoses are appropriate for all the refrigerants and have the thread 1/4".

Vacuum pumps of REFCO company. Highly-productive light two-stage vacuum pumps have safe impeller structure and ideally suit for maintenance of domestic refrigeration equipment and air-conditioning systems. Systems operating on the refrigerants of HCFC group can be vacuumized till the least value of residue pressure equal to 0,1 кПа or even less; systems operating on the refrigerants of HFC group, - till 0,04 кPа or less. Value of vacuum depends on the measuring scale; therefore, it is recommended to use electronic vacuum meter (DV-150 Vacu Test model).

Technical characteristics of one- and two-stage pumps ROYAL-2, RS-4, RD-4...RD-8 re given in the first table, parameters of electric motors - in the second table.

Electronic automatic halogen leakage detectors of "TIF Instruments Inc." company (USA). Appliances are designed to detect refrigerant leakage in refrigeration aggregates. After start of the appliance, there is immediately started searching of refrigerant leakage. Telemeter signal calculated by the computer is increased both in speed and in frequency when a source of leakage is approaching. Halogen leakage detectors of both individual and blend refrigerants - R11, R12, R500, R503, R22, R123, R124, R502, R134a, R404A, R152, AZ-50, R402A, R402B, R507.

In the table there are given technical characteristics of halogen electronic leakage detectors certified after SAE J1627, for refrigerants R12, R22, R134a, R507 and R404.

Electronic halogen leakage detectors are completed with flexible test rod, and some of them - with spiral flexible lead allowing to move the head with sensible element to hardly accessible places. Into the handle of the test rod there is built in mechanical pump creating directed gas flow to a sensitive element which accelerates searching of the place of leakage.

More advanced models TIF5650A and TIF5750A have on the handle of the test rod reset button designed to adjust different hum level.

Leakage detector TIF5650A is used for detecting of CFC refrigerants (R11, R12, R22, R502), HFC (R134a, R404A, R507) and others. Aside from the built-in pump, it is provided with the indicator lamp of the leakage level. Accuracy of indication is 20 gm/year.

TIF5750A model has a specially developed mode (Super Scanner), increasing sensitivity of leakage detector several times more (up to 10). This leakage detector is provided with analyzing and scanning device allowing to perform quick and extremely sensitive searching of leakages.

Ultrasound leakage detectors of "TIF Instruments Inc." company (USA). In this series of leakage detectors, there is used up-to-date electronics for catching ultrasound appearing when gas leaking (in vacuum or under pressure effect); at the same time, the principle of operation of appliances does not depend on the type of gas.

All the leakage detectors are provided with flexible test rod of about 400 mm, have autonomous battery feeding (9 V) and feeding indicator. TIF6600 leakage indicator has a leakage indicator, as well as the handle of sensitivity adjustment, TIF6500 appliance has reset button for hum cutoff. Using along with leakage detectors TIF6500 and TIF6600 of a highly-frequent transmitter TIF6501 allows to detect non-hermiticity in refrigeration chambers, reservoirs, etc.

Technical characteristics of ultrasound leakage detectors TIF6500 and TIF6600, as well as leakage detector TIF6500 of highly-frequent transmitter TIF6501 are given in the table.

Electronic sight glass TIF-4000A. It makes it possible to look inside the pipe with the refrigerant with the help of ultrasound. At that there are used two gauges: one as a signal source, the other one - for its reception. Gauges are made in the form of cleats, which can be attached to any metallic pipe. Sound irregular sound of the appliance increases in frequency when detecting bubbles in the liquid line or drops in the gaseous line. Moreover, a number of indicators signalize about the movement of bubbles in the pipe.

With the help of electric glass it is possible to optimize charging of the refrigeration system with the refrigerant for its operation with maximum effectiveness and to refuse installation of simple sight glass, to control distribution of flow in multi-section evaporators, to adjust thermoregulating valve, etc.

Electronic thermohygrometer MIK-3000. This thermohygrometer with digital indication has the following technical characteristics.

* Native analog - battery "Corund" or "Krona".

Appliance WM-150 for temperature measuring. This is a small-size appliance with digital indication. Such appliances are used when repairing domestic refrigerators and deep-freezers. The appliance is supplied in a set with the conductor of 1 m long and temperature transmitter.

Electronic temperature indicator ROF-80. Temperature indicator is provided with gauge and digital light indication, ensuring simple reading. Quick installation on the panel is realized thanks to available clicks.

Mechanical temperature indicator 15165. It has capillary with temperature sensitive ballon, as well as adjusting screw. The appliance measures temperature of gases and liquids.

Thermostat SP-ST. Designed for the refrigeration equipment with the range of temperature adjustment from -35 to +35 ^oC. Thermostat is supplied with connection of voltage of 250 V (16 А) or 380 V (10 А).

Electronic weighs and agitators. A number of foreign companies offer not expensive, manually adjusted electronic weighs TIF9010, TIF9015 and TIF9025 and super up-to-date programmed agitators TIF9050, TIF9050A, TIF9075 and TIF9075CR (USA), used at charging of the refrigeration contour or ballons with the refrigerant. All the weighs are not sensitive to roughness of surfaces on which they are installed.

Portable electronic weighs TIF9010 Slimline, used when filling of the old model ballons, being of only 5 sm thick, allow to weigh ballons with mass up to 34 kg, which conforms to the standard of filling ballons with the refrigerant. Scale interval of the weighs is 25 gm, measuring error is 2 %.

Electronic weighs TIF9025...TIF9075CR are designed for measurement of mass up to 68 kg. There exists a possibility to increase maximum permissible mass twice.

Automatically programmed agitators precisely fulfill all the commands introduced into the program; therefore, there's no necessity to always watch the process of charging of the refrigeration contour or ballons with the refrigerant. Agitator TIF9075 is manufactured with two separate inlets for non-compatible refrigerants (for example, R12 and R134a).

Technical characteristics of electronic weighs and automatic agitators are given in the table.

Pincers- piercing 14210 for installation of pipe socket with shredder valve. This item is designed for immediate incision into hermetic domestic refrigerators and deep-freezers. Pincers-piercing (Fig. right) are manufactured of high quality chrome-vanadium steel with removable head and shredder valve. The process of using of pincers-piercing is simple: they perform incision with diameter of 6 mm of the suction valve and the refrigerant is removed through charging hose. After completion of the process of maintenance, they disconnect the pipe socket with the help of pincers and solder it to the pipe.