CN85205720U

CN85205720U - Pipe union with oval bore

Info

Publication number: CN85205720U
Application number: CN 85205720
Authority: CN
Inventors: 石笑萓; 安子畴
Original assignee: XI-AN COAL MINE DESIGN INST
Current assignee: XI-AN COAL MINE DESIGN INST
Priority date: 1985-12-28
Filing date: 1985-12-28
Publication date: 1986-10-15

Abstract

The utility model discloses a pipe hoop joint, which is composed of a pipe clip (1), a rubber sealing ring (2), a pipe termination (3) and a connecting bolt (4). The essential points of the utility model are that the trapezoidal section in the cavity of the previous pipe clip is changed into an elliptical section, and the top of the rubber sealing ring is also made into the corresponding shape to be matched with the elliptical section. Consequently, the phenomenon of the stress concentration is reduced. Both the theory and the practice prove that the improvement of the structural shape the pipe clip has higher bearing capability and lighter weight than the normal pipe clip and is more suitable for the high pressure and large pipe diameter.

Description

Pipe union with oval bore

The utility model relates to the pipe collar joint of a kind of pipe coupling, particularly a kind of self-energized seal.It plays the connection of pipe and the seal action of medium.

The pipe collar joint is by pipe clamp, rubber seal, and pipe end connects, and connecting bolt is formed.Pipe clamp generally is divided into two lobes, also can be many lobes, by being bolted on the pipe.Rubber seal embeds the pipe clamp inner chamber, fits with it, also compresses pipeline simultaneously.Pipe clamp is stuck on the boss that pipe end connects, pipe end connect then with the pipeline welding that is connected together.

Self-energized seal is that pressure medium seals in the tube.Medium enters in the seal ring cavity in the pipe, and medium produces pressure to the seal ring cavity, and the lip of seal ring compresses pipe end and connects, and pressure is big more, and sealability is good more.When medium does not have pressure, but give the just leakproof of tight power by seal ring.

The pipe collar joint has had history decades abroad, because its tangible advantage, for example simple installation seals reliably, and volume is little, is applicable to various media etc., has been that various countries institute generally adopts.But up to now, external this series products of producing, the section configuration that its pipe clamp inner chamber is adopted is all trapezoidal.Be that two trapezoidal drift angles are wedge angle or little arc transition is arranged.The pipe clamp stress of this shape is concentrated relatively more serious.During working state, pipe clamp is subjected to the end thrust and the radial pressure of medium.Caliber is big more, and axial force is also big more, with square being directly proportional of caliber.Axial force connects on the shoulder that acts on pipe clamp by pipe end.Higher or when being subjected to fatigue ruption and influencing, two drift angle places of pipe clamp trapezoidal cross-section can be by drawing crack especially under the situation of the big caliber of high pressure when pressure.Pressure testing found that the stress of trapezoidal pipe clamp inner chamber sharp corner is concentrated very serious, and in the improvement design afterwards, we once increased to r=8mm with knuckle radius r=4mm, and stress descends to some extent, but decline scope is not obvious.So, be not effective solution only according to strengthening fillet radius.

In order to improve the bearing capacity of pipe clamp, especially for the big caliber of high pressure, wish to reduce wall thickness, give full play to the intensity of material, reach not only economy but also purpose of safety, the present invention improves pipe clamp cavity shape in the past.

Optimum configuration according to pressure vessel head is spherical or oval-shaped reason, and solution of the present invention is: make the trapezoid cross section of pipe clamp inner chamber into elliptic cross-section, the outer rim of rubber seal is also made corresponding shape, fits with it.

The result who does like this can significantly reduce the stress of dangerouse cross-section.Undertaken that intensity is calculated and analyze by electronic computer, and test proves that all the stress distribution of elliptic cross-section is even that the stress concentration phenomenon is improved greatly, on the main hazard section, maximum stress reduces by 18.5% than the trapezoidal cross-section of r=4mm.

Further improvement of the present invention is pipe clamp and pipe end to be connect the shoulder that boss matches be designed to arc transition, and product in the past is all the right angle at this place, and it is serious that stress is concentrated, and changing wedge angle is that fillet has obviously relaxed the concentrated phenomenon of this place's stress.

Theory and practice all proves, by the improvement of above structure shape, makes this kind pipe clamp have the ability of destroying than the higher bearing capacity of common pipe clamp and endurance, thereby makes the pipe collar joint more safe and reliable, and weight saving, particularly suitable to the big caliber of high pressure.For example design pressure is 100Kg/cm ²(9807Kpa), the joint of caliber 250mm is pressurized to 300Kg/cm ²In the time of (29421Kpa), the bolt distortion, pipe clamp does not but have distortion, and the seamless steel pipe that joins with it is sometimes all washed open cut by pressure, and pipe clamp does not have any distortion, damage, seals still fine.Pipe clamp after the improvement, production technology is simple, owing to eliminated two minor radius corners of inner chamber, for casting technique provides convenience, has eliminated shrinkage cavity, and the concentration zones of steam vent helps the rate of reducing the number of rejects and seconds.

Be described below with reference to accompanying drawing:

Fig. 1 is a kind of pipe collar joint three-dimensional view of original structure.

Fig. 2 is the pipe collar joint sectional view of original structure.

Fig. 3 is the sectional view of original trapezoidal inner chamber pipe clamp.

Fig. 4 is the sectional view of improved oval-shaped cavity section pipe clamp.

Fig. 5 is the rubber seal sectional view that cooperates with oval-shaped cavity.

As shown in Figure 1, 2, the pipe collar joint connects (3) by pipe clamp (1), pipe end, rubber seal (2) and bolt (4), and nut (5) is formed.The section configuration of pipe clamp inner chamber all was trapezoidal in the past, as shown in Figure 3, when pressure is high, the crack can occur at its sharp corner.Improvements of the present invention are, change the trapezoidal cross-section of pipe clamp inner chamber into elliptical section, as shown in Figure 4.Embodiment's long axis of ellipse is about two times of minor axis among the figure, has obtained effect preferably.Major axis is 1.5～2.5 with the optimum range of the ratio of minor axis.

Claims

1, a kind of pipeline connects the pipe collar joint of usefulness, connect (3) and connecting bolt (4) is formed by pipe clamp (1), rubber seal (2), pipe end, the section configuration that it is characterized in that the pipe clamp inner chamber is oval, and the outer rim of rubber seal is also made corresponding shape, fits tightly with it.

2, pipe collar joint as claimed in claim 1 is characterized in that pipe clamp (1) connects the shoulder that (3) boss matches the circular arc transition is arranged with pipe end.

3, pipe collar joint as claimed in claim 1 is characterized in that the oval-shaped major axis of pipe clamp inner chamber and the optimum range of the ratio of minor axis are 1.5～2.5.