Structural characteristics and working principle of single clamp sleeve pipe joint
Single sleeve can be divided into single edge type and double edge type according to the cutting edge of the sleeve.
The traditional single sleeve pipe joint is mainly composed of joint body, single sleeve and nut.
Card sets of forming surface hardness is higher, after heat treatment in soft, screw nut, the card sets under the action of the pressure along the joint axis of the cone to move forward in the body, card sets of variable shape into tapered hole at the same time, cutting sleeve and the joint body contact surface seal cone, at the same time card set of evenly into seamless steel tube outer wall and inner blade to fastening and sealing effect.
The middle of the sleeve is convex, with elastic effect, can reduce leakage and prevent nut loosening.
At present, most of the single jackets we use are double-edged jackets. The double-edged sleeve plays the role of double sealing. The front edge of the sleeve cuts into the pipe and forms a ring of flange F, and the sleeve fixes the outer wall of the steel pipe. The back edge can evenly distribute the force of the jacket to the whole conical area of the jacket, improving the sealing reliability.
The sleeve is gradually driven into the steel pipe by the nut. When the front edge A and the back edge B of the sleeve successively cut into the steel pipe to the design depth, the edge C acts as the stopping action, so that the stress acting on the sleeve is evenly distributed and the possibility of the cutting edge causing damage to the pipe is reduced. After the nut is pressed, the steel tube is tightened with the tail ring E of the clamp sleeve, which effectively reduces the vibration resistance and impact resistance.
Single sleeve connectors are suitable for hydraulic and pneumatic pipelines up to 45MPa. Due to the flexibility of the sleeve, when the temperature changes, the sleeve can adjust itself by its own compression or expansion, which can not only prevent the stress concentration of the edge, but also increase the anti-vibration performance.
Although there are many advantages of single card sleeve joint, but a large number of use cases prove that it still has shortcomings:
(1) The sealing performance decreases in the environment with large temperature difference. Because the sleeve and steel pipe, joint body material is different, thermal expansion coefficient is different, when the temperature difference is large, the gap between the joint body and the sleeve, between the sleeve and steel pipe may be generated, resulting in leakage.
(2) Poor performance for multiple disassembly and assembly. According to experience, after the domestic single card sleeve pipe joint is disassembled for many times, the conical surface in the joint body will be damaged, the joint body or the nut will be off, and it is easy to produce leakage.
(3) Poor consistency of assembly. The hardness of the joint body is low. In order to avoid damaging the conical surface in the joint during assembly, it is necessary to preinstall the clamp sleeve. Single-card sleeve pipe joints are mostly pre-assembled by hand, which requires higher assembly skills. The technical level and working attitude of workers directly affect assembly quality.
