Since its inception in 1906, The American Society of Sanitary Engineering has adopted the fundamental policy of "Prevention Rather Than Cure". This policy has been used in the formulation of programs to educate the plumbing industry and the public in the safe and correct manufacture and installation of plumbing components. Therefore, backflow prevention devices represent a large part of the ASSE Standards Program.

ASSE 1060, The Standard for Outdoor Enclosures for Backflow Prevention Assemblies was issued in 1996. G & C Enclosures was the first manufacturer to have its products certified under this new standard on 11 March, 1998.

The Standard includes enclosure types for freezing and non-freezing locations and segregates them into three basic classes.
Class I enclosures are freeze protection enclosures with heat sources and insulation.
Class II enclosures are freeze retardant enclosures with insulation only.
Class III enclosures are non-freeze protection enclosures with no insulation or heat.

Some of the requirements of ASSE 1060 are listed below. Tests and observations of the largest OS&Y enclosure of each design type are performed by independent ASSE approved test laboratories for each requirement.

One of the most important sections of this standard concerns the drainage performance of the enclosure. A reduced pressure principle backflow prevention device can expel large quantities of water and contaminants. If the drainage capacity of the enclosure is not adequate, the contaminated water may accumulate and submerge the device, thereby creating a cross connection. Therefore, proper function of the drainage system of the enclosure is necessary for a correct and safe backflow installation.

ASSE 1060 certified enclosures are required to drain at the following rates:

There can be no more than six inches of liquid in the enclosure at any time so that at least a six inch air gap is maintained between the relief valve and the surface of the liquid.

Under Section 3.3 Drainage Performance Test of the present ASSE 1060 Standard, the manufacturer is given the option of testing a 3 inch sized enclosure or the largest size manufactured. In other words, if a manufacturer makes enclosures housing up to 12" backflow devices, he only has to test the drainage system on a 3" sized enclosure to certify the drainage capabilities of all sizes including the 12". Since a 3" sized enclosure only requires drainage capacity of 450 gpm, how can the manufacturer know how to size the drains on a 4", 6", 8", 10", or 12" enclosure? ASSE recognizes this discrepancy and the 3" option will be dropped in the next revision. All manufactures who tested at 450 gpm will have to re-test at the flow rate of their largest listed enclosure. In the meantime, you may want to ask ASSE if the manufacturer tested a 3" sized enclosure at 450 gpm or the largest enclosure he manufactures.

It should be noted that G & C Enclosures has ASSE Listed Models through 10". The 10" Models were tested at the University of Southern California School of Engineering Foundation for Cross-Connection Control and Hydraulic Research Laboratory at 1100 gpm. We have asked ASSE to make this information a part of our listing for public use.

All ASSE 1060 Class I listed enclosures are required to be designed to maintain +40 degrees F inside with an ambient temperature of -30 degrees F. Various heaters and heating systems are used by the manufacturers to achieve these goals.

A very important thing to know concerning electric heaters is that the ASSE Standards Committee has recently ruled that the interiors of backflow enclosures are damp locations as defined in Article 100 of the National Electrical Code. The reason for this ruling is that water can accumulate in the interior of an enclosure from several sources. Some of these are listed below:

1. Sprays of water from test cocks during testing and/or maintenance.
2. Leaks in the piping or backflow assembly.
3. Discharge from a reduced pressure principle backflow preventer caused by pressure fluctuations, foreign material in the check valves, a ruptured diaphragm in the relief valve assembly or normal operation.
4. Condensation caused by the piping and assembly temperature being below the dew point temperature of the surrounding air.
5. The intrusion of rain water between the concrete slab and the walls of the enclosure.
6. The intrusion of rain water around, under and through drain openings.
7. Dampness inherent in a concrete slab placed on the ground.

Therefore, heaters installed in these enclosures must be liquid tight to meet the requirements of the National Electrical Code. The National Electrical Code was established in 1896 and has evolved into being the most widely recognized code in the world. It is adopted by law throughout the United States. The Code is sponsored by the NFPA (National Fire Protection Association) and is also known as NFPA 70. The Code brings the latest electrical safety requirements to the electrical industry.

Article 424-12(b) of the 1999 and 2002 Editions of the National Electrical Code states that: "Heaters and related equipment installed in damp or wet locations shall be approved for such locations and shall be constructed and installed so that water or other liquids cannot enter or accumulate in or on wired sections, electrical components or ductwork."

The "RH" series of heaters provided by G & C Enclosures is listed by ETL as suitable for use in damp or wet locations and intended for heating enclosures housing backflow preventers. ETL (Edison Testing Laboratories) and UL (Underwriters Laboratories) are independent, product safety testing and certification organizations which test products of all descriptions (plumbing, electrical, mechanical, etc.) to known standards and list them as certified to the test standard. ETL and UL are members of NRTL (Nationally Recognized Testing Laboratories). Please click on "ETL Listing" below to view ETL document.

It should be noted that ETL requires the RH heater to be mounted a minimum of 6" above the ground (concrete). The reason for this requirement is that by definition of ASSE 1060 there may be liquid inside the enclosure up to a maximum depth of six inches. Therefore, any heater mounted below six inches would be submerged.

Heaters used in ASSE 1060 listed products are not necessarily liquid tight and therefore some do not comply with Article 424-12 of the 1999 and 2002 National Electrical Code. The only way to verify that the heat source is suitable for use in damp locations is to see the UL or ETL Listing. This listing shows that the product has been tested for public safety by an independent laboratory for use in damp or wet locations.

Sand bags are placed on the top of the enclosure at the rate of 100 lbs/sf. The purpose of this test is to determine if the enclosure can support this vertical load for a period of 24 hours without any damage or permanent deformation.