1 Selection

The correct selection of hydraulic hose, matter to whether the entire hydraulic system normal work and enterprise procurement cost. The selection of hydraulic hose from its size, pressure, bending radius,temperature adaptation range, considering the factors such as working medium and the activity space.

(1) hose size

Hydraulic hose diameter is too small, will with large internal medium flow,making the system more efficiency to reduce, fever, and may cause too large pressure drop, affect the performance of the whole system; diameterwill increase the purchase cost, the normal operation of influence system.When the pipe clamp fixed or the hose through the steel tube, should pay attention to the outside diameter of hose. The use of hose, diameter andflow velocity diagram, can choose suitable hose diameter rapidly, as shown in figures. For example: the hydraulic system flow is 75 L/min,recommended velocity is 6 pipeline m/s, the 2 coordinates of the points into1 lines, and the diameter of the pipe column of the intersection of 15.9 mm is required for the inner diameter of the hose.

(2) the pressure hose

Hydraulic hose more pressure, the higher the price. The maximum working pressure hose shall be based on the system pressure determination,selection must consider to ensure the system normal operation, but alsosave the purchasing cost. Because of the existence of impact load in the hydraulic system, the maximum working pressure of the maximum workingpressure hose are generally larger than those of the hydraulic system, and the hose burst pressure is generally the maximum working pressure of 3 ~ 4 times.

(3) the temperature range

The environmental temperature and hydraulic hose work through the highor low, can affect the life and ability of the pressure hose, so no matter how to change hose working state, the temperature of the environment may limit of temperature resistance over rubber hose. The limits recommendedtemperature is lower or higher than the hose, are likely to reduce thedamage caused by the performance of rubber hose, hose, causing the hose leak. So near the heat distribution tube, must take measuresappropriate.

(4) the working medium

Should be based on the hydraulic medium, selection of materials suitable for rubber hose. The working medium of engineering machinery hydraulic oil is selected, hose, should be selected and used by the hydraulic oilcompatible hose.

(5) the bending radius

In the choice of high pressure hose, should pay attention to high pressurehose bending radius. Calculation of bending radius, should withhold lengthminus front joint. If the hose using the bending radius bending radius is less than the rubber parts, will make the bearing capacity and service life of thelower hose. The allowable pressure and diameter is the same in the hose,priority should be to choose a smaller bending radius of the hose, it canensure the structure layer is not damaged.

(6) the activity space

Engineering machinery hose is more, the space is limited, when used in regular contact with hard objects or friction, so depending on the situation in the hose is added to external sheath.

Select the hose after, also must choose the corresponding pipe joint.Determine the pipe or tube joints are usually connected by their device interface, so to consider whether it is appropriate joint. For the high pressure pipeline, should choose to withhold tube joint permanent.

2 installation notes

The correct installation of the rubber hose is very important. If the hose is too long, not only affect the appearance, but also increase the cost of; such as hose is too short, not enough leeway, is easy to be damaged in the process of using in engineering machinery. Arrangement of hose, hoseshould be avoided because of tensile, compression, distortion or in acute office because of friction and damage, to ensure the safe use and service life. Must be carefully checked before installation of the hose, check the project including the size, type, and the length of the hose assemblycleanliness, and whether there are jams, blistering, delamination defects.

(1) do not distort

When installing hose, make sure it is not distorted, or when the pressure is too large will damage the hose or made loose connections. If in someunavoidable hose twist of the occasion, the twist angle should not exceed 5 degrees.

(2) length should be left margin

Stress causes the hose length change, the change rate of up to -4% ~ +2%. In addition, many hose construction machinery are movement withmechanical occurred, and should therefore be left margin during installation, otherwise the long-term use can cause leaks at the joints, and even the joint loosening. Hose should be set aside enough free length. The general free length L = 1.5 D (D is the outside diameter).

(3) bending radius should be enough

Hose should have sufficient bending radius. Bending radius is large enough(i.e., leave a proper length), can prevent the generation of hose damage and throttling phenomena; too small bending radius would seriously reduce the hose life, and produce too much pressure loss, reduce work efficiency.The bending radius of the general R is larger than or equal to (8 ~ 10) D (D is the outside diameter).

(4) the appropriate choice of elbow and accessories

When the hydraulic pipeline engineering machinery is more complex, should use the right elbow and accessories. This can make the rubber hosedosage was reduced, and can reduce the hose camber and twist, avoidhose produces additional stress. The correct use of the pipe clamp, can guarantee the stability of pipeline arrangement, avoid the hose and theequipment damaged by contact surface, but also can make the rubber hosearrangement is more beautiful and elegant, orderly and reasonable.