How to use Hydraulic hoses?

What should you watch out for when using high  pressure hydraulic hoses?

1. Poor manufacturing quality

(1) The inner and outer layers of the high-pressure hydraulic hose wall are oil-resistant rubber, and the middle is (2 to 4 layers) cross braided steel wire or spiral wire.

Poor quality hoses will appear:

Uneven thickness of hose wall;

Wire braid too tight, too loose or too few steel wire layers;

After the hose is pressurized, the deformation (elongation, shortening or bending deformation) is larger;

Poor air tightness of the outer layer leads to corrosion of the steel wire.

The poor seal of the inner layer glue makes the high pressure oil easily enter the wire layer;

Adhesion between the adhesive layer and the wire layer is insufficient.

The above situation will cause the hose to withstand the decrease, and eventually burst in the weak wall of the pipe.

(2) Improper selection of crimping amount and crimping speed when assembling hoses and joints, or

unreasonable selection of structure, material, and size of the joints can lead to over-tightening or

loosening of hoses and joints, causing early damage to joints. During assembly, if the buckle pressure is

too small, that is, if the pressure between the connector and the hose is too loose, the hose may come

out from the joint in the early stage of use under the effect of oil pressure; if the buckle pressure is too

large, the joint and the hose pressure Over-tightening can easily lead to local destruction of the inner

layer of the hose, resulting in cracks. High-pressure oil can enter the steel wire directly from the cracked

area, and then spurt along the gap between the steel wire to the tail of the outer jacket, or it can

accumulate along the wire layer to a certain point. Causes the outer layer of rubber to bulge or even

burst. When the hose and the connector are assembled, if the crimping speed is too fast, the internal

rubber may be damaged and the wire layer may be broken, so that the hose may be damaged

prematurely in use. In addition, unreasonable joint design, poor processing quality, can also cause

internal damage; if the joint material is not properly selected, in the buckle process easily deformed,

thus affecting the buckle quality, shorten the life of the hose.

2. Improper use

Under the premise of quality assurance, if it is used improperly, the service life of the hose will be greatly

shortened. In practice, most high-pressure hoses are damaged due to improper use.

(1) Frequent and severe pressure shocks. High-pressure hose burst, generally not due to the pressure

caused by too much static pressure, but with the severity and frequency of pressure shocks. When the

construction machinery is in operation, the sudden increase or decrease of the oil pressure in the oil

pipe repeatedly causes frequent pressure shocks to the oil pipe, resulting in increased damage to the oil

seals in various parts, foaming and cracking of the hose, and loosening of the pipe joints. Leakage

phenomenon. Therefore, when operating, the valve stem must not be pulled too hard and must be

gentle.

(2) The temperature of the oil is too high. When the construction machinery is in operation, the hydraulic

system heats the oil due to power loss, and the influence of outside temperature (especially in the

summer) can make the oil temperature rise sharply. The higher the oil temperature is, the more

susceptible the banana is to aging, the elasticity will be worse, the strength and sealing performance will

be reduced, and the hose will burst soon. Therefore, in the operation, when the temperature rise of the

hydraulic system is too high or too fast, the cause should be promptly identified and eliminated. In the

summer operation, especially during continuous operation, necessary cooling measures should be taken.

(3) hose selection, installation is not reasonable. When replacing the high-pressure hose, the length of

the selected hose, the number of layers of the steel wire, the shape and size of the joint must be

reasonable, and the bending degree of the hose should be minimized; when tightening the joint nut, do

not make the hose twist, excessive bending and Distortion will greatly reduce the service life of the

hose; protective measures shall be taken on some locations where friction may easily occur to prevent

the hose from bursting due to wear.