A gas-filled protection device for the back of pipeline welding

Abstract

The invention discloses a back inflating protecting device for pipeline welding, and relates to the technical field of pipeline welding. The back inflating protecting device for pipeline welding is applicable to pipelines with various sizes. The device is characterized in that resisting air bags sleeve two ends of a connector; an air flowing pipe which extends out from supporting parts at two endsaxially penetrates a resisting assembly; a first flow dividing pipe and a second flow dividing pipe are arranged the air flow pipe and correspondingly communicate with the resisting air bags at two ends of the connector; a separating sheet for resisting air flow is arranged in the air flow pipe and is positioned between the first flow dividing pipe and the second flow dividing pipe; and a first control valve and a second control valve which are connected and disconnected with the first flow dividing pipe and the second flow dividing pipe are correspondingly arranged at two ends of the air flow pipe. According to the device, the resisting air bag is elastic, and the expansion width can be adjusted based on the inside diameter of the pipelines with different size, so that the back inflatingprotection can be performed on the pipelines with various sizes in welding.

Description

technical field [0001] The invention relates to the technical field of pipeline welding, in particular to an inflatable protection device for the welding back of pipelines. Background technique [0002] In addition to the high-temperature molten pool on the front of the weld needs to be properly protected during pipeline welding, necessary measures must also be taken on the back of the weld to block the oxidation of the oxygen in the air to the weld. If no weld protection measures are taken, the weld metal on the back is easily oxidized during the welding process, the alloy elements are burned, and welding defects are prone to occur, resulting in a decrease in the mechanical properties and corrosion resistance of the weld metal. Generally, inert gas is considered as a better protective medium, and the device that can be used to implement gas protection on the back of the weld is called "back gas protection device" in the industry. In the existing pipeline welding process, t...

AI Technical Summary

Problems solved by technology

However, for large-diameter pipes or when the pipe fitting group is relatively long, the overall argon filling is used. The disadvantage of this is that the consumption of inert gas is large, resulting in high production costs; the long time of inflating leads to low production efficiency; The air tank has a large space, even if a large amount of inert gas is filled, the air cannot be effectively evacuated, the protection effect is poor, and the welding quality is seriously affected, resulting in the need to polish the weld after welding or pickling passivation, wasting a lot of manpower and material resources

[0003] Patent CN201620972770.7 discloses a stainless steel pipeline welding back gas protection device, which includes a blocking part and an inflation tube. The blocking part and the stainless steel tube form a storage chamber, and the blocking part is connected with the inflation tube to facilitate inflating the storage chamber , the quality of the weld has been effectively guaranteed, which greatly saves the amount of argon used. The accommodating cavity formed between the device and the stainless steel is sealed by the front baffle and the rear baffle and the pipe wall. The front baffle and the The rear end baffle is made of fluororubber, and the size of fluororubber is made according to the inner diameter of the corresponding pipe. Therefore, the specific fluororubber size of the device can only be adapted to the back gas protection of one inner diameter of the pipe. If necessary, different specifications To improve the back gas protection of pipelines, it is necessary to replace the protective devices with different baffle sizes, and it is necessary to prepare back gas protection devices of different specifications and sizes in advance, which greatly increases the manufacturing cost and leads to poor applicability. In addition, due to the need for fluororubber It forms a sealed state with the pipe wall. During production and processing, the outer diameter of fluororubber is usually slightly larger than the inner diameter of the pipe wall. Therefore, when the back gas protection device is installed in the pipe, it needs to be dragged hard to reach the position of the weld. If the fluororubber Excessive dimensional processing errors may cause jamming in the pipeline

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