Hydraulic pipe fittings standard
Assembly of clamp sleeve type pipe fittings
Pre-installation,the most important link of the pre-installation of the sleeve type pipe fittingsdirectly affects the reliability of the seal. Special precursors are generally required.Fitting with small diameter can be pre-assembled on the bench vice. The specific approach is to use a fittings as the matrix, the nut, card sleeve boutique documents, value download .Clamp down on the pipe. There are mainly sleeve type straight-through pipefittings, sleeve type end straight-through connecting head, sleeve type three-way pipefittings and other types of the author found that, even if it is a batch of goods from the same manufacturer, the depth of the conical hole on the joint body is often not the same, resulting in leakage, and this problem is often ignored. The correct way is to use what kind offitting tail is used at one end of the pipe, and the correspondingfitting end is pre-installed with the same type offitting, so as to avoid leakage problems to the greatest extent.
The end face of the pipe should be flush. After the pipe is sawed, it should be polished evenly on grinding wheel and other tools, and the burrs should be removed, cleaned and cleaned with high pressure air before use.
During pre-installation, the coaxiality of the pipe and the joint body should be kept as far as possible. If the pipe is too deviation, it will also cause sealing failure.
The pre-installed force should not be too ambassador that the inner edge of the sleeve is just inserted into the outer wall of the pipe, and the sleeve should not be obviously deformed. In the pipeline connection and then according to the specified tightening force assembly. The tightening force of towel 6-1 sleeve is 64-115N16 towel MMR259N towel 18mm is 450N if the sleeve is seriously deformed during pre-installation, the sealing effect will be lost.
Sealant and other fillers are prohibited. Some people in order to achieve better sealing effect, in the card sleeve coated with sealant, the sealant was rushed into the hydraulic system, resulting in hydraulic components Yin nihole blockage and other faults.
When connecting the pipe, the pipe shall have enough deformation allowance to avoid the pipe being subjected to tensile force. (IV)·When connecting the pipeline, it should be avoided that it is subjected to lateral force. Excessive lateral force will cause loose sealing
When connecting pipes, it should be good at one time and multiple disassembly should be avoided, otherwise the sealing performance will be deteriorated.
Installation of sleeve type pipe joint
(1) Pickling of pipes required in Chapter 9 shall be carried out first;
(2) Cut off the pipe according to the required length with sawing machine or special pipe cutting machine, and dissolving (such as flame cutting) or grinding wheel cutting is absolutely not allowed. Remove the internal and external round burr, metal chips and dirt at the pipe end: remove the anti-rust agent and dirt at the pipefitting; At the same time to ensure the roundness of the pipe;
(3) the nut sleeve has been set into the pipe, the front edge of the sleeve (small end) from the pipe mouth at least 3mm and then insert the pipe into thefitting body cone hole, top until,
(4) Slowly tighten the nut, turn the pipe until it does not move, and then tighten the nut 2/3 to 4/3 times:
(5) Open and check whether the jacket has been cut into the pipe and whether the position is correct. The jacket is not allowed to have axial movement, but a little rotation;
(6) Tighten the nut after passing the inspection. Two, pipefittings leakage prevention in the hydraulic system, whether it is metal pipefitting or hose fitting, there are easy to produce leakage problems. For the sleeve type pipefitting, mostly due to the larger external force or impact of the pipe sleeve loosening or pipe end deformation caused by leakage, at this time should check whether the sleeve is out of round, cutting edge without defects. Whether the pipe end is intact and the clamping degree of the clamp nut, etc., but also to eliminate the external force of the pipeline. For flaring type pipe fitting, mostly due to excessive flaring, quality does not meet the requirements or multiple disassembly, resulting in flaring deformation or cracks caused by leakage, at this time, the front end can be cut off for flaring again. If the top pressure of the male and female cone is used for sealing, the leakage is mostly due to the damage of the two cones, and the cone can be ground with abrasive sand. In some use ". Ring on the end face or outer diameter sealing occasions, the leakage reasons are as follows :" O "ring aging or deformation caused by leakage; ." The shape ring assembly is not in place, so that when the two planes are connected, the pressure is uneven or the shape ring is cut to cause leakage: the "O" shape ring is not compacted, and the elastic deformation is insufficient to cause leakage; ." The groove of the ring stop is too deep and causes leakage. In this regard, it is necessary to re-select the same outer diameter and thicker section ". Ring, also can be with the sealing plane sealing groove cutting or grinding processing, in order to reduce the depth of the groove, so that ". The ring has sufficient elastic deformation (compression should generally be between).