Practical Tips for Refrigeration Equipment Maintenance

It is difficult to weld iron pipe joints of condensers directly with phosphor copper welding rods during refrigeration equipment repair, especially for beginners, as poor weld joints often remain despite repeated attempts. Before welding iron pipes, remove paint and rust from the welding area with sandpaper, and scrape off all coatings if present. Heat the iron pipe with a welding torch, then apply a thin layer of brass solder to the joint using a brass welding rod dipped in borax. Fit the copper pipe to be welded in place, and finish the welding easily with a phosphor copper welding rod.

When refilling small gas cylinders for portable welding torches from large liquefied gas cylinders at room temperature, only a small volume of gas can be filled. After preliminary filling, place the small cylinder in a refrigerator for several hours to freeze it. Then invert the large liquefied gas cylinder and connect it to the small cylinder for refilling. This method increases the gas filling capacity for convenient use.

The sealing gaskets of three-way valves and refrigerant cylinder valves used in maintenance will age over time and lose sealing performance.

If replacement gaskets of specific sizes are unavailable, rubber rings for tape deck drive wheels with matching inner and outer diameters can be used as substitutes. When replacing the sealing gasket on the valve stem of a three-way valve, apply synthetic silicone grease to the gasket and stem. Ordinary engine oil will accelerate gasket aging, while silicone grease can enhance the sealing effect.

For repairing corroded evaporators in large refrigerator freezing compartments, when bending and routing copper pipes to replace the original grid-type evaporator, use nylon cable ties for electrical wiring to fasten the new pipes.

This method is fast and firm, and is particularly applicable for on-site repairs.

Flocculent dust and dirt tend to accumulate on the steel grid of condensers of aging refrigeration equipment and are hard to clean. During maintenance, use a low-intensity diffused flame from an oxygen-free liquefied gas welding torch to burn off the dirt, which can then be easily brushed away.

To evacuate a refrigerator during repair, use the unit's own compressor for self-evacuation. Weld a three-port adapter onto the original filter, and attach a long thin copper tube to the bypass port next to the air inlet for exhaust.

Insert the tube opening into a container of refrigeration oil. Complete welding of other connections, and install a three-way valve and refrigerant cylinder. Close all valves and power on the compressor to start evacuation.

Observe the exhaust tube submerged in refrigeration oil. Once no more bubbles emerge, open the three-way valve to inject a small amount of refrigerant and then close the valve. Before refrigerant bubbles stop coming out of the exhaust port, use a tube sealer to clamp the bypass exhaust pipe near the filter, cut off the excess pipe section and seal the opening by welding. The compressor can then be shut down or additional refrigerant can be charged.