Introduction of sleeve type hydraulic fittings

Description of clamping sleeve fittings principle

The connection principle of the sleeve type pipe joint is that the sharp inner edge of the sleeve gradually cuts into the outer wall of the steel pipe under the action of progressively increasing tightening torque, so as to achieve the connection purpose of the pipe fitting with reliable sealing. Bayonet fittings have the following advantages

1. Simple structure, reliable sealing performance, easy to use, excellent manufacturing, light and beautiful appearance

2. No gasket, no welding, material saving, repeated assembly and disassembly performance is good.

3. The influence of pipeline impurities on system performance is reduced because the clamp casing joint is not welded. Therefore, the clamp sleeve type pipe joint is increasingly widely used in the oil, gas as the medium of hydraulic and pneumatic equipment pipeline, especially suitable for burning danger, high altitude work and frequent assembly and disassembly occasions.

The structure of sleeve type hydraulic fittings

The structure of the sleeve hydraulic fittings is mainly composed of a fittings body with a 24° conical hole, a sleeve with a sharp inner edge, and a nut with a pressing effect. When tightening the nut, the sleeve is pushed into the 24° cone hole, and then deformed, so that the cutting edge of the sleeve cuts into the steel pipe and forms a circular cutting groove, so as to play a sealing role. Because the jacket is elastic, it can withstand larger impact and play a role in preventing loose.

Installation of clamp sleeve fittings 

1.Saw off the appropriate length of seamless steel tube and remove burrs at the port. The end face of the pipe should be perpendicular to the axis with an Angle tolerance of less than 0.5°. If the pipe needs to be bend, the length of the straight line from the end of the pipe to the bending part shall not be less than three times the length of the nut.

2. Cover the nut and cutting ring on the seamless steel pipe. Make sure that the nut and sleeve are installed in the opposite direction.

3. Apply lubricating oil on the threads and sleeves of the pre-assembled fittings body, insert the pipe into the fittings body (the pipe should be inserted to the end), and tighten the nut.

4. Tighten the nut until the sleeve catches the pipe. The turning point can be felt by increasing the tightening torque.

5. After reaching the pressure point, tighten the clamping nut 1/2 turn.

6. Remove the pre-assembled fittings body and check the embedding of the edge of the sleeve. The visible protrusion belt must fill the space of the end face of the sleeve. The cutting ring can be slightly rotated, but not axially pushed.

7. The final installation, the actual installation of the fittings body thread coated with lubricating oil, and the screw nut with the tightening force can be felt until the increase, and then tighten 1/2 circle installation is completed. The socket fittings should be cleaned up inside and outside the fittings connected with the socket during installation. The nozzle must be polished smooth, and the surface can not have burrs, concave and convex surfaces. And there should be no bending at the embedded part of the pipe and the socket fittings, otherwise there will be leakage at the connection between the socket fittings and the steel pipe. It is better to use the pipe of uniform material at both ends of the clamping sleeve joint, which can effectively prevent leakage.

After the steel pipe is inserted into the sleeve joint body, the intensity of fastening the sleeve should not be too large. The sleeve should be screwed to the tail or 2/3 of the thread step by step, and then the sleeve can be tightened with a wrench.