The vermin-proof Aluminum Watertite Locking Well Caps with large screened air vents from Boshart Industries Inc. are de-signed to be easy to install and easily accessible for maintenance work. Tabs cover the setscrews to avoid unwanted removal of the cap, and the O-ring system is said to ensure a reliable seal to casing with a second O-ring used to seal the cover and retainer ring. With the six-bolt design, a positive compression seal is achieved by tightening the six bolts. These well caps also come in a setscrew design where the positive seal is achieved by tightening a single screw on a specially tapered surface.

Boshart Industries Inc., Card No. 42