This special shaft bubble, developed especially for leak tests of manholes or drains, is characterized by its low weight, size and easy handling. Three ring bolts allow easy vertical positioning and ensure a good fit of the bubble in the manhole.
Manhole bubbles with passage are used for leak tests for sewer manholes. They are offered in four different nominal sizes from 600 to 1000mm. The passage is provided on both sides with a 2″ internal thread to enable the connection of a Storz coupling. The compressed air quick coupling for filling the manhole test bladder is fitted with a 1/4 " connection and allows the bladder to be changed quickly. Depending on the size of the shaft bladder, either retaining loops or towing eyes are provided for easy installation.