DD270482A1 - METHOD FOR WELDING PIPE SUPPORTS TO THE WALL OF TANKS OR GRASS TANKS - Google Patents

Abstract

The invention relates to a method for welding pipe socket to the wall of tanks or large containers. The invention is applicable to large Behaeltnissen that are emptied of combustible gases or liquids, have at least one manhole and must be provided with a pipe socket or a similar opening welding technology. The mark of the invention is that initially introduced holes 13, then a known protection chamber 5 inside and the pipe socket 1 to be mounted outside brought into position and by clamping screws 8, which are inserted through the holes 13, and clamped by means of clamping rails 6 mutually in that the protective chamber 5 is then purged with protective gas, that is then welded in sequence of the raw sockets 1, if necessary also welded on cut-out reinforcements 4 and finally the projecting tank wall plate 14 is cut out. At the end of all welding work, the tools used 6; 6; 8 dismantled together with the fanned tank wall plate 14. figure

Description

First, through holes are made at the location on the tank wall to which the pipe socket is to be attached. Thereafter, only a protective chamber on the inside and the prepared pipe socket to be mounted are brought into position on the outside and clamped against each other with clamping screws which are inserted through the through holes. Finally, all necessary welding work is carried out on the outside and technologically cut out the tank wall plate at a required time.

In a further embodiment, it is provided to clean the inner wall portion to which the pipe socket is to be attached before attaching the protective chamber, to flush the attached protective chamber before beginning and during the welding under pressure with nitrogen and during the separation of the tank wall plate, the protection largely Flood the water. In application of the device according to the invention on the welding of pipe socket or similar feedthroughs in the wall of tanks and large containers, in which combustible residual gases are included, make technology and work equipment easier and still functionally reliable.

embodiment

The invention is explained in more detail below with reference to an agreement. First, to be provided with a pipe socket 1 tank for liquid or gaseous fuels to empty completely. Thereafter, all safety measures must be taken to enable a safe entry into the tank through the manhole. The safety measure also includes the internal cleaning of the tank wall at the point at which welding and cutting work is to be carried out with trichlorocarbon. Furthermore, the actual process steps are as follows:

- Inserting holes 13 for clamping screws 8 by careful drilling from the outside;

- introducing the divided protection chamber 5 into the tank and its assembly;

- Simultaneous mounting of the protective chamber 5 on the inside of the tank wall 3 under Zwemp henf joints of a sealing strip 7 and the pipe socket 1 on the outside under mutual bracing by means of parallel clamping screws 8, which are inserted through the holes 13, wherein the clamping rails β inside and outside to better Distribution of forces can be useful;

- The now closed protection chamber S with nitrogen via pipe 10; 11 releasing combustible residual gases and maintaining a reduced supply of nitrogen until the completion of all subsequent welding and firing operations;

- attach pipe socket 1 with flange 2, then weld;

- attach and weld cut-out reinforcements 4 if necessary;

- constantly monitor the temperature of the tank wall 3 during welding work, cool it if necessary, or insert welding breaks;

- Flood lower half of the protection chamber 5 to form a water bath 12 via pipe 9;

Burning out of the tank wall plate 14;

- push burnt-out tank wall plate 14 inwards on the clamping screws 8 and grind the flame cut;

- Pump off water bath 12;

- Loosen the clamping screws 8, disassemble the clamping rails ε with the clamping screws 8 and the tank wall plate 14 and remove the protection chamber 5 on the inside, disassemble and remove it via the manhole.

- At the end of the welding and firing work, the required fitting can be mounted on the pipe socket 1 and the tank prepared for replenishment.

Claims (4)

1. A method for welding pipe sockets to the wall of tanks or large containers in the presence oinder the welding on the inside hermetically shielding and purged with inert gas protective chamber, characterized in that first at the authoritative point of the tank wall Durchgangsbohrungnn be mechanically introduced, that then the inside protection chamber and the Outer pipe sockets against each other by clamping screws, which are felt through the through holes, are held and that finally welded to the pipe socket and the tank wall plate is cut out. 2. The method according to claim 1, characterized in that at the beginning of the welding area is cleaned inside. 3. The method according to claim 1, characterized in that the gehaiterte protection chamber is flushed before beginning and during the welding work under pressure with nitrogen. 4. The method according to claim 1, characterized in that during the separation of the tank wall plate, the protective chamber is largely flooded with water. For this 1 page drawing Field of application of the invention The invention is applicable to large, mostly stationary tanks or large containers for flammable liquids or gases, provided that the tanks or large containers have at least one manhole and are subsequently to be provided by welding with a pipe socket or with a similar opening. Characteristic of the known state of the art Welding work on the aforementioned tanks or large containers are only allowed if an explosion or fire hazard is excluded by the stored goods. This is the case when the container is both completely emptied and from combustible residual gases, ζ. B. is completely rinsed free by an inert gas. However, such a measure requires a considerable effort, especially since the content to be cleared can amount to several thousand cubic meters. According to DD 226 804 (B 23 K, 9/225), a device for repair welding to tanks and large containers, which are intended for the storage of combustible liquids is known. The device presents itself in two protective chambers, which rest both on the inside and on the outside of the wall where repair welds to be performed, by vacuum cuffs. Both protective chambers are filled with inert gas to prevent the entry of combustible gases from the tanks to the weld. In addition, the outside protection chamber is equipped with a pleated collar and a welding device as well as with a viewing window to prevent the entry of atmospheric air to the weld. Both protective chambers can be filled with water up to a certain height in order to avoid damage to the vacuum sleeves due to welding spatter in the lower area. Last but not least, safety measures are provided which, depending on the vacuum in the vacuum sleeve, interrupt the welding current or flood the tank with water up to the welding point. This known device has the disadvantage that its function, which consists in keeping the weld of combustible gases and in the suppression of the air ingress into the tank, depends strongly on the respective vacuum pressure of the vacuum chamber, because with decreasing vacuum, z. B. by insufficient completion of the vacuum sleeve on the inner wall or leaks in the supplying vacuum power or by interruption of the vacuum pump, the risk that one or the other protection chamber is in the absence of pressure force and thus that their protective function suddenly lost. Another disadvantage of the known device results in considerable material-technical effort. Should be attached to a tank or bulk container that is for flammable liquids in use. Pipe sockets or other externally inwardly continuous connection elements are mounted by welding technology, then arise with the help of the known device then additional difficulties, which consist in that at least the outer protection chamber would have to be solved several times to bring the parts to be welded on site and that Also additional brackets would have to be welded. Object of the invention In application of so-called protective chambers should be reduced in welding work on tanks and large containers for welding pipe socket of the material-technical effort and the reliability can be increased. Explanation of the essence of the invention According to the objective, the technical problem is to employ means other than vacuum, rather than the vacuum-related retention of the protective chamber on the container wall. The solution in the context of the stated objective and technical task consists in the following: