High pressure steel wire braided rubber hose is an important hydraulic system component of construction machinery. During use, faults such as leakage, cracking, rupture, and loosening often occur. Operators often simply replace the hose without analyzing the cause of the fault. Shortly after use, the same malfunction may occur again, which is attributed to the quality of the hose. The following will introduce the reasons for the damage.

1、 External adhesive layer failure

1. Surface cracks on the rubber hose

In cold environments, surface cracks on rubber hoses can cause them to bend. If cracks are found on the outside of the hose, attention should be paid to whether there are cracks in the rubber inside the hose, and it should be decided whether to replace the hose immediately. Therefore, do not move the hose or disassemble the hydraulic system in a cold environment. If you need to work in a colder environment for a long time, you should replace the cold resistant rubber hose.

2. Bubbles appear on the surface of the hose

Due to poor quality or improper use of the hose, bubbles appear on the surface of the hose. If there are bubbles in the middle of the hose, it is often a quality problem during the production of the hose, and a qualified hose should be replaced in a timely manner; If bubbles appear at the hose joint, it is likely due to improper installation of the joint. There are two types of connector and hose connection ends: detachable and crimped. The detachable connector jacket and connector core are hexagonal in shape. The outer wall of the joint core is conical, which facilitates the disassembly and installation of the rubber hose. After connecting the joint core and nut, insert the steel wire to prevent loosening. The buckle type rubber hose joint consists of a joint sheath and a joint core. During assembly, the outer rubber layer needs to be peeled off, the joint core head needs to be inserted, the joint sheath needs to be tightened, and then the rubber hose is compressed to the corresponding amount using a mold on a dedicated equipment to achieve a sealed connection.

3. Unbreaked but with significant oil leakage

A large amount of oil leaked from the hose, but no rupture was found. The reason is that when high-pressure liquid flows through the rubber hose, the internal rubber is eroded and scratched, until the steel wire layer leaks out on a large area, causing a large amount of oil leakage.

4. Severe deterioration of the outer adhesive layer resulting in microcracks

This is a manifestation of natural aging of high-pressure steel wire braided rubber hoses. Due to aging and deterioration, the outer layer continuously oxidizes, covering the surface with a layer of ozone layer. Over time, the ozone layer thickens. If the hose is slightly bent during use, microcracks will occur. In this case, the hose should be replaced.

2、 Internal adhesive layer failure

1. The inner rubber layer is hard and cracked: the main reason is that plasticizers added to rubber products give the rubber hose elasticity and plasticity. However, if the hose overheats, the plasticizer will overflow.

2. The inner rubber layer is severely deteriorated and visibly swollen: The inner rubber layer of the hose is severely deteriorated and visibly swollen. The reason is that the rubber material inside the high-pressure steel wire braided rubber hose is incompatible with the oil used in the hydraulic system and deteriorates due to chemical reactions.

3、 Failure of reinforcement layer under compression

1. The high-pressure hose ruptured, and the braided steel wire near the rupture rusted. The rubber hose is broken, peel off the outer adhesive layer for inspection. The braided steel wire near the gap has been found to have rusted. This is mainly due to the influence of moisture or corrosive substances on the layer, which weakens the strength of the hose and leads to rupture under high pressure.

2. Irregular wire breakage phenomenon within the reinforcement layer

After the rubber hose ruptured and peeled off the outer layer, no rust was found on the reinforcement layer, but irregular wire breakage occurred in the length direction of the reinforcement layer, mainly due to the high-frequency impact force on the rubber hose.

4、 Failure manifested at the rupture site

1. One or more fractures, with neat cracks

The main reason for this phenomenon is that the system pressure is too high, exceeding the pressure resistance of the hose.

2. Twisted at the rupture site

The reason for this phenomenon is that the rubber hose is excessively twisted during installation or use.

High pressure steel wire braided rubber hoses are generally composed of four parts: an outer rubber layer, a steel wire reinforcement layer, a middle rubber layer, and an inner rubber layer. The inner rubber layer is directly in contact with hydraulic oil and is generally made of synthetic rubber. The load-bearing capacity of a rubber hose depends on the steel wire reinforcement layer, which is the skeleton of the hose and is usually woven and wrapped with steel wire. If various attributes and functions cannot meet the requirements, it will lead to problems during use.