Compression. The main advantage of such bounces is seamless. Connected to the main pipe by squeezing the control ring located in the pipe. If we compare more clearly, then compression bounces are mounted according to the principle of a folding cane — inside there is a thread on which the pipe is screwed. Outwardly the connection is not visible and the discharge is completely sealed. Such bounces are widely used in water pipelines, irrigation systems of fields, etc. D. By the way, if you compare the divets of the steeply reduced GOST 17375 2001 with others, then they will be the best precisely due to the lack of external seams.