Rubber freon hoses for car air-conditioning installations are mounted with special fittings made of aluminium or steel. The type of the fitting connection can be individually designed to match a particular type of a car. The angle and shape of the fitting pipe determine how the fitting is attached. The typical types of connections in the car air-conditioning installations are given below:
- pipe fitting with UNF female thread (swivel nut) and o-ring seal;
- fitting wtih UNF female thread (swivel nut), SAE type (45° cone);
- compressor fitting with female thread 1″-14 UNF (swivel nut);
- pipe fitting with UNF male thread with o-ring seal;
- fitting with UNF male thread (socket of a quick release coupling);
- fitting with UNF female thread (swicel nut), ORFS type;
There are many other types of fittings available. Hose connectors are also common, sometimes adapters and quick release couplings as well. The fittings of large size (for buses) are compliant with different standards (flanges, metric threads).
Braze nipples allow to replace a used hose length as they can be soldered to the connection of the original fitting – for service purposes.
Straight and angle fittings are available. They may be equipped with a built-in refrigerant charging valve.
There are several options of mounting fittings to rubber freon hoses:
- fast assembly system – fitting with a hose tail of special shape, assembled with clips using special pliers; clip holders are used to set the position of clips; the system is intended for service purposes mainly;
- crimped with ferrules – one-piece fitting consists of a sheet metal ferrules integrated with the fitting, crimped with special profile dies on crimping machines – system intended for serial production;
- reusable – first the ferrule is screwed onto the hose, then the fitting is screwed into the hose and the ferrule – the system is not very popular nowadays.
When the fitting is selected, it is necessary to specify the type and size of connection, inner hose diameter and outer hose diameter (is it a standard – thick wall or lightweight version).