| C500 – Metal-Seated Gate Valves for Water Service
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C500 – Metal-Seated Gate Valves for Water Service

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 closed on 2/11/18.

Send comments to:
Emily Meek
303.347.6192 phone
303.795.7603 fax

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 Therefore, this copy is not suitable for continued utilization and is intended only for comment purposes.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 iron-body, metal-to-metal seated, nonrising-stem (NRS) gate valves, including tapping gate valves, 3-in. (75-mm)  through 72-in. (1,800-mm), and outside screw and yoke (OS&Y) rising-stem gate valves, 3-in. (75-mm) NPS through 72-in. (1,650-mm), with either double-disc gates having parallel or inclined seats, or solid-wedge gates. These valves are suitable for use in approximately level settings within water systems. These valves are intended for applications where fluid velocities do not exceed 16 ft/sec (4.9 m/sec) when the valve is in the fully open position. 
1.1.1 Valve pressure ratings. The minimum design working water pressure shall be 200 psig (1,379 kPa) for valves 12-in. (300-mm) and smaller, and 150 psig (1,034  kPa) for valves with diameters of 14-in. (350-mm) and larger.
1.1.2 Conditions and materials not described. This standard is not intended to describe special conditions of gate-valve installation or operation, such as built-in power drive, installation in unusually corrosive soil, conveyance of unusually corrosive water, excessive water hammer, or operation in a throttled position. Such conditions are beyond the intended scope of this standard and require special consideration in design and construction. Joint accessories for end connections, such as bolts, gaskets, glands, follower rings, and so forth, are not described in this standard. 

MAJOR REVISIONS
Major changes made to the standard in this revision include the following:

  1. A note to the user on packing a valve or replacing its stem seal while under pressure has been added to the foreword (II.A.2.1)
  2. A note to the user on bypasses has been added to the foreword (II.A.3)
  3. A note to the user on chlorine and chloramine degradation of elastomers has been added to the foreword (II.B)
  4. A purchaser option has been added regarding whether 54-in. (1,350-mm) and larger valves shall have a reduced or full-size waterway (III.A.14)
  5. The standard has been expanded to include sizes up to 72 in. for nonrising-stem (NRS) gate valves and outside screw and yoke (OS&Y) rising-stem gate valves.  Values for these sizes have been added to the relevant tables (Sec. 1.1, Tables 1, 2, 3, 5, 6, 8, 11, 12, 13).
  6. Information regarding applicability of the standard to wastewater applications has been added (Sec. 1.3.1)
  7. Definitions have been added for grooved and shouldered joint, nominal valve size, potable water, reclaimed water, and wastewater.  The definition of nominal pipe size has been expanded. (Sec. 3)
  8. A requirement for valves used in potable water service to be certified to ANSI/NSF 61 has been added (Sec. 4.2.1)
  9. Table 1 has been simplified.
  10. The size of waterway section has been clarified for requirements for full waterway clearance and reduced waterway clearance and a new table with waterway clearance requirements added (Sec. 4.3.2 and Table 2).
  11. A section clarifying laying lengths of flanged valves 12 in. (300 mm) and smaller has been added (Sec. 4.4.3.2.3)
  12. Addition of grooved and shouldered end joints (Sec. 4.4.3.6). 
  13. Additional alloys have been added for stem nuts, gates, and body seat rings (Table 7).
  14. Stainless steel has been added as a material for guides (Sec. 4.4.7.1) and rollers (Sec. 4.4.8.1.2).
  15. Stem diameter requirement have been clarified (Sec. 4.4.9.4)
  16. Proof of design leakage testing has been removed (Sec. 5.1.1).
  17. The marking requirements have been updated to include marking of “C500” on valves (Sec. 6.1).
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