AWWA Comment Period Begins on ANSI/AWWA C520 - Knife Gate Valves, Sizes 2 In. (50 mm) Through 96 In. (2,400 mm)
November 23, 2018

AWWA solicits public comments on all proposed new AWWA Standards, and on all proposed revisions, reaffirmations, or withdrawals of existing AWWA Standards. The referenced standards project is being considered for approval and the publication of this notice begins the 45-day public comment period for AWWA and ANSI. An electronic public review copy of the proposed standard can be obtained for review during the comment period by emailing etssupport@awwa.org. Comments must be submitted in writing to the AWWA contact listed below no later than the last day of the comment period specified herein. Such comments shall be specific to the section(s) of the standard under review and include sufficient detail so as to enable the reader to understand the commenter's position, concerns and suggested alternative language, if appropriate.

AWWA Comment Period closes on 1/7/19.

Send comments to:
Tim McCandless
303.347.6285 phone


The review copy will be edited for publication and may also be revised as appropriate based on any comments received during the public comment period. Therefore, this copy is not suitable for continued utilization and is intended only for comment purposes.

Final publication of the standard may take several months. When it is available, a notice will be published in the official notice section of Journal - American Water Works Association. The standard becomes an effective AWWA standard on the first day of the month following such publication in Journal - American Water Works Association.

SCOPE
This standard describes bonneted, bonnetless, cast, and fabricated steel; stainless-steel; and cast ductile-iron body knife gate valves with resilient or metal seats, including tapping knife gate valves, for use in water, wastewater, and reclaimed water systems with pH range from 6 to 12 and a temperature range from 33°F to 125°F (0.6°C to 52°C). The minimum design pressure rating shall be 150 psig (1,034 kPa) for nominal sizes 2 in. to 24 in. (50 mm to 600 mm), and the minimum design pressure ratings for nominal sizes 30 in. to 96 in. (750 mm to 2,400 mm) shall be 25 psig (172 kPa), 75 psig (517 kPa), or 150 psig (1,034 kPa).

MAJOR REVISIONS
Major revisions made to the standard in this edition include the following:
1. Added advisory information for metal seated valves (Sec. II.B.6).
2. Changed minimum pressure requirements (Sec. 4.3.1).
3. Increased manual actuator design factor (Sec. 4.4.1).
4. Seat leakage was modified (Sec. 5.1.3.2).