Irrigation rubber tubing or pipes - have water outlets in wavy tubing which automatically close when pressure falls

摘要

A length of rubber tubing is produced in a wave form with a central semi-circle joined at each end to two other semi-circles curving in the opposite direction. The centre semi-circle is elastically deformed to a straight line and a hole made in the wall of the tubing. This length of tubing is joined to another length to form a complete loop and when supplied with water at pressure the hole becomes V-shaped and allows the water to pass out freely. When the water pressure falls to zero the hole closes up and prevents the unintended loss of water or the ingress of roots or other foreign matter.