Above Grade Installations - Protective Enclosures

An above grade installation is generally necessary to provide gravity drainage from RPZA devices. The additional benefits of improved access and enhanced safety are also realized with an above grade installation. Two companies, "Hot Box" and "Hydrocowl", have designed prefabricated insulated enclosures that provide heat, gravity drainage and removable access panels for servicing and testing. As an alternate, wood frame, fiberglass, steel, masonry or precast concrete structures may be utilized. All enclosures shall be designed:

· With a floor elevation that is at least 6 inches above finished grade.

· To provide adequate clearances around the device to access the test cocks, shutoff valves, check valves and relief valve.

· With electric heaters or heat trace wire for any water service used year round.

· With provisions for natural or artificial light.

· With full flow gravity drains according to the drainage requirements.

· With security measures such as locking doors and panels, flow alarms or flow indicator lights, power indicator lights, etc.