SU1493411A1 - Method of connecting tubes to tube sheets - Google Patents

Abstract

The invention relates to the welding of capillary tubes and tubes of small diameter (up to 5 mm) with a tube plate or flange. The purpose of the invention is to improve the quality of welded joints by maintaining the dimensions of the bore of the tube. The pressure of gas supplied to the tube during the execution of the weld, is calculated by the formula P _T = P ^_H. E ^{(D / 1 + D)} ₁ , where P _T is the pressure in the tube, kg / cm ²

P _H - external pressure in the welding zone, kg / cm ²

E-base of natural logarithm

D is the internal diameter of the tube, mm. The invention makes it possible to maintain the dimensions of the flow area of the pipes and to improve the quality of welding, not allowing the hole to melt or to break the protection and ejection of the weld pool metal.

Description

cl

with:

The invention relates to the welding of capillary tubes with a diameter of 0.1–2 mm and tubes of small diameter 3–5 mm with pipe discs or flanges, and may find application in mechanical engineering and other public goods.

The purpose of the invention is to maintain the flow area and optimize the mode.

welding.

The method consists in that the pressure of the gas supplied to the tube is calculated by the formula (J) i

g,

RT RM "

i 4

where PY is the pressure in the tube, kg / cm;

Рц - narzgzhnoe pressure in the welding zone, kg / cm;

e is the base of the natural logarithm;

d is the internal diameter of the tube, mm.

Choosing the pressure of the gas supplied to the tube in accordance with the specified formula makes it possible to strictly regulate its flow rate and to prevent the hole opening in the tube in the event of a low flow rate, as well as a possible ejection of the weld pool metal and a violation of the protection of the weld zone at its increased flow rate. Gas is fed into the tube through the seal. From the outside, the protection is effected by gas supplied to the burner. Rotation is attached to the weld site. The welding speed is set depending on the wall thickness of the tube,

PRI m e RO Welded batch of capillary tubes with an inner diameter of 0.3 mm automatic argon

42 WITH

00

four

arc welding with a non-melt electrode with local protection in the following mode; Rc - 1.05 at. (in the burner); RT - 1.1 at. (In the tube); about; - 2 оВ / s; „„ „20А; t. „0„ 1 s; t. - 0.3 s. After welding, the flow section was checked at the place where the tube was welded to the flange. There was no narrowing of the gauge. Thinning of the walls — no more than 0.005 mm, which amounts to 2%. There is no curvature of the tube axis.

The application of the proposed method allows preserving the size of the pipe bore and improving the quality of welding.

Claims (1)

Invention Formula The method of connecting tubes with tube sheets, in which Editor S. Lisin Compiled by, Tyutchenkova Tehred A. Kravchuk Proofreader M. Maksimishinets Order 3932/15 Circulation 894 VNIIPI State Committee for Inventions and Discoveries under the State Committee on Science and Technology of the USSR P3035, Moscow, Zh-35, 4/5 Raushsk nab. Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 during the welding process, tubes with a tube board are supplied with protective gas, and welding is carried out in a protective gas medium, characterized in that, in order to improve the quality of welded joints by maintaining the dimensions of the tube flow area ,. pressure of the gas supplied to the tube, calculated by the formula one P - P where rt r n e d pressure in the tube, kg / cm; external pressure in the weld zone, kg / cm; the base of the natural logarithm; inner tube diameter, mm Subscription