CS248699B1 - Welded blade elbow gro pipe of circular or oval cross section - Google Patents

Abstract

The welded blade elbow is made of two obliquely cut pipes and a flange, and the obliquely cut pipes and flange are connected by connecting pipes. This design reduces the stress in the weld and does not cause dynamic stress on the blades of the elbow.

Description

The invention solves the construction of a welded elbow for circular or oval cross-section for gases and liquids, which is inexpensive to manufacture, reduces weld stresses and does not cause dynamic stress on the elbow blades by flowing vortices and additional pressure losses of the projections inside the elbow.

The weld blades used for the circular or oval cross-sectional piping are formed from an obliquely cut pipe connected to a ring of constant width, carrying blades. The angle of the bevel cut is determined by the bend angle of the knee; for rectangular elbow is 45 °. A known ring-to-ring connection is either by butt welding or by a pipe-to-ring connection. Always the blades and stiffeners are welded to the wreath. The tension in the welds deforms the wreath. To weld butt tubes to the ring, it is necessary to laboriously align the ring with the tubes. Therefore, the metal collars are welded perpendicular to the rim on both sides, extending inwards and outwards of the knees. It is possible to weld obliquely cut pipes on the collar without complicated fitting and thus create a bend. The plate thickness of the pipe and the rim is the same. In order to minimize deformation of the collar during welding, it is made of a sheet of several times thicker than the ring and tube. The greater the thickness difference of the welded sheets, the greater the amount of stress in the welds. The resulting cracks cannot be removed by annealing. The inner edges of the collar protruding into the knee increase the pressure loss of the knee and cause or increase the dynamic strain of the blades.

The aforementioned drawbacks are eliminated by a welded blade elbow for a circular or oval cross-section, which is characterized in that the welded blade elbow for a circular or oval cross-section, formed from two obliquely cut pipes and the collar has obliquely cut pipes connected to the dowel via connecting pipes.

The advantages of the present invention are different for both embodiments. Due to the butt-welded pipe elbow, the advantage of the present invention is to make it easier to align the pipe with the connection pipe and also to reduce the pressure loss in the elbow by rounding the inner edges of the bend, which have a greater effect on the amount of losses. In the case of a knee with a collar is an advantage

The solution according to the invention reduces stress in the weld, since the connecting tube can have a wall thickness equal to or smaller than the knee body tube. Furthermore, the solution according to the invention does not have the disadvantages of overlapping the collars into the flow cross section of the knee. and increase pressure loss from both collars ·

Fig. 1 is a cross-sectional view of the plane of symmetry of a rectangular vane column for circular cross-sectional piping; Fig. 2 is a cross-sectional view of the connecting pipe in the plane of symmetry with and outside the bend side; again cut the connecting pipe in the plane of symmetry, ais on the inside of the bend

The blade elbow consists of a collar 1, blades 2, two connecting tubes J and two obliquely cut tubes 8. The blades 2 are rigidly connected to the dowel 2. The obliquely cut tubes 6 are formed by cutting a single tube at 45 °. 1 are of a plunger of a standing fat man. Connecting pipes 2 “They have a wall thickness of usually 55 to 85 proosnt thicknesses of obliquely cut pipes 5 to reduce the inherent stress in the weld · The diameter of the connecting pipes J is 12 to 15 times larger than its wall thickness · Pipe Connector 2 ·

The same design can be applied to elbows with different bending angles. The blade elbow of the invention can be used for all gases and liquids.

Claims (1)

object of the invention Welded blade elbow for pipes of circular or oval cross-section, made of two obliquely cut tubes and a collar, characterized in that the obliquely cut tubes (4) and the collar (1) are connected by means of connecting tubes (3).