In municipal construction, pipeline renovation and other engineering operations, due to careless operation or unclear pre-planning, the bellows are often broken. Bellows are generally 6 meters each. Once broken, it seems to be only local damage, but in fact it may lead to the failure of the entire pipeline function. So, when encountering problems such as broken bellows and broken bellows, how to deal with them? Is there a simple and effective repair method?

1. Overall replacement method: the most secure solution

Considering the structural characteristics and use requirements of bellows, the most economical and effective way is to replace them as a whole. When the bellows are broken, the construction should be stopped immediately, and then continue to excavate along the pipeline to completely expose and remove the entire damaged pipeline. When replacing, choose a new pipe that is completely consistent with the original pipe specifications and materials to ensure that it meets the relevant national standard requirements such as "Buried Polyethylene (PE) Structural Wall Pipeline System", such as the national standard of Hubei HDPE double-wall corrugated pipe. Taking HDPE double-wall corrugated pipe as an example, the ring stiffness, wall thickness and other parameters of the new pipe must meet the standards to ensure subsequent normal use.

Second, targeted repair strategies for different degrees of damage

(1) Slight damage

If the corrugated pipe is only partially dug, a small area of cracks or holes can be repaired by welding. For HDPE double-wall corrugated pipe, use a special HDPE electrode, through hot air welding, the electrode is melted and filled in the damaged part, and then reinforced by geotextile winding to enhance the strength and sealing of the repair part. During operation, attention should be paid to cleaning up the damaged part to ensure that the welding surface is dry and free of impurities to ensure the welding effect.

(2) Medium damage

When the excavation area is large, but not completely broken, the pipe hoop connection repair method can be used. Select the pipe hoop with a slightly larger diameter than the damaged pipe, put the pipe hoop on the damaged part, and then fill the sealing glue or rubber ring between the pipe hoop and the pipe, tighten the bolts on the pipe hoop, so that the pipe hoop and the pipe are closely fitted to achieve the purpose of sealing and reinforcement. This method is suitable for temporary emergency treatment to gain time for subsequent overall replacement.

(3) Severe damage (digging)

For the case of complete digging, even if the local repair can be temporarily restored after use, there is also a large safety hazard. It is recommended to choose the overall replacement first. If the whole pipe cannot be replaced immediately due to special circumstances, the electric fusion heat shrinkable sleeve can be used to connect. The electric fusion heat shrinkage sleeve is placed at the interface of the two broken pipes and heated by an electric fusion welding machine to fully integrate the sleeve and the pipeline to form a firm connection. However, this method requires high operation technology, requires professional operation, and the connection cost is relatively high.