How Many Types Of Hydraulic Fittings?

 

The hydraulic hose joint assembly is composed of a rubber tube and a metal joint. It is mainly classified according to the working pressure range which you can measure with the help of different pressure gauge and the connection form of hose and joint.

We can classify them by working pressure range that has a potent influence on them.

 

If the working pressure is less than 3Mpa, mainly the hydraulic hose fittings are woven with cotton thread. It is mainly used to control oil circuits, automobile brake pipelines, and some hydraulic machine tools, for example, industrial hose crimping machines.

 

If the working pressure is between 3 and 10 MPa, which is mainly made up of type I and II large diameter hydraulic hose woven by steel wire. It is mainly used for medium and low-pressure oil circuits and oil return circuits.

 

If the working pressure is above 31.5 MPa, it is mainly the steel wire winding pipe with a diameter  of less than 31.5. With the development of ultra-high pressure and high-power hydraulic machinery, the demand for it is increasing.

 

Of course, according to the connection mode of hose and joint, it can be divided into the detachable type and buckle type.

 

1) The buckle type hose joint assembly is that after the hose and the connector are pre-configured, the outer sleeve of the joint is forced to shrink inward by a certain size under the cold state by an external force, so that the connection between the hose and the joint is trustworthy.

 

2) The joint and hose of the detachable assembly compress the inner rubber layer of the hose through the core with an outer cone to make it close to the inner core of the joint sleeve. That is connected by the inverted cone gap formed between the core and the joint sleeve while pressing the inner and outer rubber layers of the hose like Parker rubber hose. But the connection quality is not stable. Therefore, domestic professional manufacturers generally adopt the buckle type.

 

The composition of hydraulic hoses such as hydraulic rubber hose will greatly influence functions of them so that workers must be cautious and skilled enough to finish their tasks. The following steps are useful.

 

1) The hydraulic hose is composed of an inner rubber layer, reinforcing layer, and outer rubber layer. The inner rubber layer is in direct contact with the oil, so it is required that it should not be corroded by the fluid under the long-term working condition and can prevent leakage. Certainly, an oil pressure tester may be helpful. It can bear certain pressure under the action of a reinforced layer. Generally, the higher the hardness, the smaller the permanent deformation after compression, the better the sealing performance. If it is too thick, it will increase its flow rate, resulting in the accumulation of excess glue in the contact end face between the joint core sleeve and the rubber tube, reducing the flow cross-section, vice versa. At the same time, the wall thickness uniformity of  the inner rubber layer is also very important as well as the pitting on the surface of the inner rubber layer.

 

2) The hydraulic hose mainly relies on the reinforced layer to bear the pressure. The wire braided rubber hose is bonded to the inner and outer rubber layers by the glue. Due to the mutual contact between the steel wires in the same braided layer, the friction between the steel wires will be caused by the different expansion and contraction of the steel wires under dynamic pressure which needs a compound pressure gauge to measure it all the time, which will affect its durability. The winding pipe is composed of two layers with different winding directions to form a working layer. There is an intermediate glue between the two layers, so there is no cross point between the two layers of steel wire in the same working layer. Therefore, it will not form stress concentration or friction and wear due to cross bending of steel wire under dynamic pressure. Therefore, it has good durability and can withstand high pressure.

 

3) The outer rubber layer of the hydraulic hose is adhered to the reinforcing layer to protect it, and chloroprene rubber is generally used. Attention should be paid to prevent its aging and cracking and affecting the life of the hose such as cloth surface rubber hydraulic hose.

 

Jazzy as a famous enterprise founded in 2005, can offer hydraulic pipe fitting products as well as cam and groove coupling. Their products are all of high-quality like brass fittings, forged fittings, and stainless steel ball valves.