For use in the Denver Water Service Area

Materials Specifications – 6
for
Swing Check Valves

4 Inch Through 24 Inch Nominal Diameter

1. General:

All valves supplied under this Specification shall be designed and manufactured in accordance with AWWA C508, with the following additional requirements or exceptions.

2. Valve Description:

All valves shall be iron body and the disc shall be swing type.

3. Installation:

Valves shall be installed in a horizontal position. Some operating conditions may dictate the need for an assisted closure feature such as a counterweight or spring to reduce check valve slam.

4. Service:

All valves shall be suitable for frequent operation as well as service involving long periods of inactivity. The operating pressure for all sizes shall be 150 psig.

5. Bolting Material:

Bolts and hex nuts used for attaching top cap to the body shall be the manufacturer's standard, either fabricated from a low-alloy steel for corrosion resistance or electroplated with zinc or cadmium. The hot-dip process in accordance with ASTM A 153 is not acceptable.

6. End Connection:

All check valves shall be furnished with flanged ends. The size and drilling shall be in accordance with ANSI B16.1 Class 125. Flanges shall be machined to a flat surface with a serrated finish in accordance with AWWA C207.

7. Testing:

Each valve after shop assembly shall be given the operation and hydrostatic tests in accordance with AWWA C508.

8. Coatings:

A.Internal Surfaces:

All internal ferrous surfaces except machined or bearing surfaces shall be prepared for coating per SSPC-SP-10. These surfaces shall then be coated with a two-part thermosetting polyamide epoxy in two or more uniform coats, or with fusion bonded epoxy, to a minimum dry film thickness of 12 mils. Epoxy coating shall conform to AWWA C550.

B.External Surfaces:

All external surfaces except machined or bearing surfaces shall be carefully prepared by removing all dirt, grease, and rust and shall be cleaned to the extent that the coating will bond to all surfaces.

The exterior of each valve except flange faces shall be shop coated with one coat of polyamide anti-corrosive epoxy primer to a dry film thickness of not less than 3 mils, or shall be prepared and coated the same as the internal surfaces.

Flange faces shall be shop coated with a rust preventive compound.

9. Certification:

The manufacturer shall furnish a sworn statement that the inspection and all of the specified tests have been made and the results thereof comply with the requirements of the applicable Standard(s) herein specified. A copy of the Certification including compliance with NSF/ANSI 61 shall be sent to Denver Water.