CS200809B1 - Pipeline connection sphere-cone - Google Patents

Description

The invention solves the shape of a pipe-to-cone pipe joint with high pressure and temperature fittings in stainless steel austenitic steel pipes.

Ball-to-cone pipe connections are known which have a cone throat angle at which the spherical surface of the plug rests less than 45 ° and are permitted for pressures up to 16 MPa at low pipe diameters up to 8 mm and flow temperatures up to 200 ° C . The use of this joint with good sealing results for higher pressures and temperatures of the flowing substance cannot be completely solved even with the recommended choice of better materials on the joint components. For some industries, such as chemistry, nuclear technology, relying in many designs on the use of durable austenitic stainless steels for pipe connections, tightening the ball-to-cone sealing joint of a standard shape due to high lateral pressures between cone and throat results in early squeezing of the cone neck with an apex angle of less than 45 °, so that the durability of such a joint at frequent disassembly is low, its tightness breaks, and the necessary repair is difficult, sometimes impossible. These difficulties are further exacerbated by the use of a pipe joint of this shape for substances with a pressure higher than the normalized 16 MPa limit.

Said difficulties can be solved by using a ball-cone pipe joint according to the invention, wherein the apex angle of the conical surface of the austenitic steel pipe throat into which the rotary curvature of the austenitic steel pipe cone surface is between

200 809

200 808

80 ° to 100 °.

The figure shows schematically an example of austenitic steel ball-cone pipe joint according to the invention. The conduit 6 of chromium-nickel austenitic steel 18Cr8Ni is terminated by a hollow pipe cone 1 with a spherical surface 5 and by means of a cap nut 4 this hollow cone 1 is pressed into the pipe socket 2 of the second conduit 7 also of chromium-nickel austenitic steel 18Cr8Ni. In this case, the apex angle θ - of the conical surface 3 of the pipe neck 2 is 90 °.

Austenitic steel ball-to-cone joint with a pipe cone tip angle between 80 ° and 100 ° has an order of magnitude greater durability while maintaining reliable tightness compared to a joint with a typical top angle of less than 43 ° and allows safe reuse of this kind a single tight connection for pressures and temperatures of the flowing substance at least twice the stated limits of 16 MPa, 200 ° C.

Also, it is easier to manufacture a conical throat with a larger apex angle, and the flow passage in such a connection has less hydraulic resistance. It also works well when connecting pipes of larger diameters than the recommended 8 mm diameter at the limit pressure and the temperature of the flowing substance.

The ball-cone pipe joint according to the invention can be used in research and industrial technology of high environmental pressures on pipes and fittings, or on the neck of pressure vessels and wells constructed of austenitic steel.

Claims (1)

Object of the invention Spherical-cone pipe connection with austenitic steel fittings, characterized in that the apex angle of the conical surface (3) of the pipe throat (2) into which the rotary wedge (5) of the surface of the hollow pipe plug (1) bears is between 80 ° to 100 °.