ASSE STANDARD # 1060 (Issued: November 18, 1996)

Performance Requirements for
Outdoor Enclosures for
Backflow Prevention Assemblies

For a complete printed text please contact:

American Society of Sanitary Engineering

for Plumbing and Sanitary Research

28901 Clemens Road, Suite # 100

Westlake, OH 44145

United States of America

Telephone: (216) 835-3040

Facsimile: (216) 835-3488

E-Mail: ASSE@IX.netcom.com

General Information

No product may be said to be ASSE approved unless the manufacturer has applied to the ASSE, has had his product tested by an official ASSE recognized independent laboratory, according to the applicable ASSE Standard, and when the product has passed the test, displays the ASSE Seal on the product.

This standard focuses on devices that provide a range of protection to backflow preventers which are mounted outside and above ground so they may avoid freezing, vandalism and tampering.

It is recommended that enclosures be installed consistent with local codes by qualified and trained professionals.

This standard was promulgated in accordance with procedures developed by the American National Standards Institute (ANSI).

Performance Requirements for Outdoor Enclosures for Backflow Prevention Assemblies

1.2 Scope

1.2.1 Description

The enclosures incorporate features to provide for freeze protection, positive drainage to prevent submergence of the assembly, security and accessibility for testing and repair.

1.2.2 Classes

1.2.2.1 Freeze Protection Enclosures

a) Class I enclosures are designed for all devices other than pressure and atmospheric vacuum breakers.

b) Class I-V enclosures are designed for pressure and atmospheric vacuum breakers.

1.2.2.2 Freeze Retardant Enclosures

a) Class II enclosures are designed for all devices other than pressure and atmospheric vacuum breakers.

b) Class II-V enclosures are designed for pressure and atmospheric vacuum breakers.

1.2.2.3 Non-Freeze Protection Enclosures

a) Class III enclosures are designed for all devices other than pressure and atmospheric vacuum breakers.

b) Class III-V enclosures are designed for pressure and atmospheric vacuum breakers.

1.2.4 Temperature Ranges

1.2.4.1 Freeze Protection Enclosures (Class I & Class I-V)

Enclosures shall be designed and constructed to maintain a minimum internal temperature of 4 (C (40(F) with the external temperature of -34( (-30(F).

3.0 Compliance Testing

3.1 Freeze Protection Capability Test (Class I and I-V)

3.1.2 Procedure

Place the enclosure in a controlled atmosphere room having minimum temperature of 4° C (40° F) on a concrete slab in accordance with the manufacturer's instructions.

***Provide electrical power to operate the enclosures heat source. Cool the controlled atmosphere room to -34° C (-30° F) and hold for 24 hours. During the 24 hour period, record the temperature inside the enclosure hourly with two (2) thermocouples.***

3.2 Drainage Performance Test (All Classes)

3.3.1 Purpose

The depth of water within the enclosure shall not exceed 150 mm (6 inches) during full flow of the backflow preventer relief discharge, nor shall the depth of the water exceed 8 mm (0.25 inches) after completion of full flow.

3.5 Access for Testing and Maintenance (All Classes)

3.5.2 Procedure

Review drawings for each enclosure submitted by the manufacturer to determine distance from edge of access opening to location of test cocks and valve handles or hand wheels. Verify that test sample meets the design criteria.

3.6 Hinged Access Panel Restraints Test

3.6.3 Criteria

Unrestrained panels and horizontal hinged panels which exceed 32 kg (70 lbs.) in weight shall result in a rejection of the enclosure.

This material is copyright protected by ASSE. For a full copy of the Standard (including text and illustrations) contact ASSE at the local listed at the front of this section.

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