Radon gas exhaust system
Rain gutter and downspout connection
Reconfigurable loop of tubular elements
Releasable coupling for air carrying tubes
Removable fluid swivel for mooring terminals
Replaceable pipe liner assembly
Resilient annular seal with supporting liner
Rigid duct with bendable elbow
Riser assembly for underground pipe connections
Rod coupling for oil well sucker rods and the like
Roll grooved pipe
Rotary joint device for a cryogenic liquid
Rust-resistant sleeve for use in a branch hole of a water pipeli