For use in the Denver Water Service Area

Materials Specification – 5
for
Flanged Rubber Seated Butterfly Valves

1. General:

Except as modified or supplemented herein, all butterfly valves supplied under this Specification shall be designed and manufactured in strict compliance with AWWA C504. Unless specified otherwise, for valve sizes beyond the scope of AWWA C504, valve design shall be based upon the maximum service conditions with minimum safety factors of 3:1 on yield strength and 5:1 on ultimate strength. All Class 250 valves shall have ductile iron bodies with flange dimensions and drilling per ANSI B16.1, Class 125.

Valves supplied under this Specification may include three types: "buried", "in-plant", and "submerged". The type of valves, class of valves and type of actuators to be supplied should be specified.

2. Service:

All valves shall be suitable for throttling service and/or frequent operation as well as service involving long periods of inactivity. Valves shall be capable of operating satisfactorily with flows in either direction. Valves shall be suitable for use in potable and non-potable service.

3. Installation:

All valves specified as "buried" shall be for buried service in horizontal waterlines with the valve shaft horizontal and operating nut shaft vertical. Body of valves will be buried and the actuators will be installed in manholes.

All valves specified as "in-plant" shall be for service inside buildings or other structures in a relatively dry environment, protected from weather. The valves will be installed with valve shaft horizontal and the actuator directly coupled to the valve body.

All valves specified as "submerged" shall be for service inside basins or reservoirs. The valves will be installed with the valve shaft vertical, and will be mounted to a pipe flange. "Submerged" valves shall be supplied with torque tubes and actuator stands as shown on Sheet 84 of the Standard Drawings.

4. Shut Off Pressure:

The maximum static differential pressure across the valve will be the same as the class of the valve. At rated pressure, the valve shall be bubble tight for flows in either direction.

5. Class of Valve:

The class of valves shall be as specified.

6. Valve Bodies:

Valve bodies shall be of short body pattern. All Class 250 valve bodies shall be ductile iron. Disc stops on the body will not be allowed.

7. Valve Discs:

Valve disc shall seat at 90 degrees to the pipe axis. Discs having hollow chambers that can entrap water will not be allowed. All Class 250 valve discs shall be ductile iron.

8. Valve Seat:

Rubber seats may be applied to either the body or the disc. The mating seat surface, in either case, shall be stainless steel or sprayed in accordance with AWWA C504. Plated mating-seat surfaces will not be acceptable.

Rubber seats shall be of new natural or synthetic rubber and may be reinforced by the manufacturer.

Rubber seats mounted on the disc shall be a continuous full circle 360-degree seal, clamped thereon with corrosion resistant retaining rings, and threaded fasteners.

Rubber seats mounted in the groove of the valve body on valves 24 inch diameter a smaller may be bonded to the body. Bonded seats must withstand a 75-pound pull in accordance to the 90 degree stripping test procedure "Method B" of ASTM D 429.

Rubber seats mounted in the valve body on valves larger than 24 inch shall be full circle 360 degree and shall be retained in the valve body by mechanical means in such a manner that the seat can be adjusted to provide a tight shutoff. All hardware used in retaining the seat in the body shall conform to all the requirements of AWWA C504. Valve shaft shall not penetrate the rubber seat.

9. Valve Shaft:

The valve shaft shall be stainless steel and may be either through or stub type and shall conform to all applicable requirements of AWWA C504. Shafts for Class 250B valves shall be ASTM A 564, UNS Designation S17400, condition H1150.

10. Shaft Seal:

Where the valve shaft projects through the valve body for the actuator connection, a shaft seal designed for positive pressure within the valve shall be provided for the following sizes of valves:

A. For valves 24 inch diameter and smaller:

The seal shall be one of the following types:

1) Self-compensating V-type packing.

2)6O-ring type contained in a corrosion resistant cartridge.

Retention of the above seals shall be designed to utilize the actuator case as a positioner of the seal. Replacement of seals shall be done without removal of the valve shaft.

B. For valves 30 inch diameter and larger:

1) Self-compensating V-type packing

2) Adjustable packing type

Retention of the above seals shall be designed to utilize a packing box with retainer or pull-down packing gland so that the packing can be field adjusted or completely replaced without disturbing any part of the valve or actuator assembly, except the retainer or packing gland follower.

On "buried" valves, the shaft seal area and exposed valve shaft shall be totally enclosed to prevent infiltration of material around the shaft seal and valve shaft during backfilling. Adjustable packing glands shall be accessible either through the bonnet as specified in Paragraph 14 or by removing the enclosure around the packing gland.

11. Valve Bearings:

Valve bearings shall conform to all applicable requirements of AWWA C504. In addition, valves furnished with an externally adjustable thrust bearing shall have the external adjusting mechanism enclosed in a substantial watertight housing.

12. Type of Valve Ends:

All valves shall be furnished with flanged ends. Dimensions and drilling shall conform to ANSI B16.1, Class 125. Flanges shall be machined to a flat surface with a serrated finish in accordance with AWWA C207. The flanges shall have full-sized bolt holes through the flanges, except that drilled and tapped holes will be acceptable only in the areas where the shaft passes through the body. Flanges with all holes tapped will not be allowed.

13. Valve Actuators:

Unless otherwise specified, valves shall be furnished with manual worm gear actuators designed and sized to develop output torques for the specified operating service and shall be sufficient to seat, unseat and rigidly hold the disc in any intermediate position for the above conditions. The maximum velocity for actuator design shall be 16 feet per second.

A. "Buried" Valves

The actuators shall be Limitorque Type HBC, or EIM Type WD, designed to operate temporarily in a submerged condition in ten feet of water.

The actuators shall be equipped with 2 inch square operating nuts. The nuts shall be 1-15/16 inch square at the top, 2 inch square at the base, and 1-3/4 inch in height. The valves shall open with a clockwise rotation of the nut.

Stop-limiting devices shall be provided in the actuator for both open and closed positions. All actuator components between the input and the stops shall be designed to withstand, without damage, an input torque of 300 foot-pounds at the operating unit.

B. "In-Plant" and "Submerged" Valves

The actuators shall be Limitorque Type "T", Auma Model GS or EIM Type WO, provided with handwheels of suitable size to open the valves with the specified maximum pull.

The valves shall open with a clockwise rotation of the handwheel.

Stop-limiting devices shall be provided in the actuators for the open and closed positions. All actuator components between the input and these stops shall be designed to withstand, without damage, a pull of 200 pounds on the handwheel.

All gearing of the manual actuator shall be totally enclosed and sealed for a lubricant formulated for a temperature range of –10°F to +150°F. Manufacturer shall fill the gear case with lubricant to 80% of full prior to shipment from the factory.

Primary gearing of actuator shall be a self-locking worm gear of high tensile bronze and a worm of hardened alloy steel with ground and polished threads.

Primary gearing shall be supplemented by spur gear attachment to comply with the following conditions of operation for all sizes of valves:

A. Minimum number of turns for complete opening or closing of valve disc shall not be less than 40 for all "buried" valves.

B. Maximum input torque required to fully open or close the valve for the specified service conditions shall not exceed 150 foot-pounds when applied to the operating nut, or an 80-pound pull when applied to the handwheel.

The diameter of the output shaft or spline of the actuator shall be sized equal to or greater than the turned-down section of the valve shaft.

All actuators shall have a valve position indicator.

14. Valve Bonnet:

"Buried" valves shall be furnished with a separate one piece cast iron or fabricated steel extension bonnet with (if applicable) access openings fitted with removable covers, located to permit access to the stuffing box for tightening the packing. The extension bonnet shall be 21 inches in length and shall be of a single diameter over its entire length. Minimum thickness of removable cover shall be 14 gauge (.0747") and shall be attached to extension sleeve with a minimum of four 1/4 inch diameter cap screws. Gasketing of the opening is not required.

15. Torque Tubes:

"Submerged" valves shall be supplied with torque tube type shaft extensions and actuator support stands as shown on Sheet 87 of the Standard Drawings. Each torque tube and actuator support stand shall be sized to operate under the maximum service conditions for the valve. The torque tube shall transmit the required torque to the valve without twisting or bending. The torque tube shall be connected to the valve shaft with a taper pin and nut or with a "keyed" fit.

16. Nameplates:

Corrosion-resistant nameplates shall be provided. There shall be one valve nameplate attached to the valve body, or for "buried" or "submerged" valves, attached to the valve actuator. The valve nameplates shall include the normal valve data and the serial number. There shall be one actuator nameplate attached to the valve actuator.

17. Manufacture:

All valves furnished shall be the latest standard products of a manufacturer regularly engaged in the production of equipment of this nature for a period of at least 5 years.

18. Testing:

The valve manufacturer shall test all valves according to AWWA C504.

19. 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 and shall be Ameron 400, Tnemec Series 140F Pota-Pox Plus, Corvel ECA-1626 or approved equal.

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.

For "buried" valves, the exterior of each valve except flange faces shall be shop coated with two coats of asphalt varnish, or shall be prepared and coated the same as the internal surfaces.

For "in-plant" valves, 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.

For "submerged" valves, the external surfaces shall be prepared and coated the same as the internal surfaces.

Flange faces shall be shop coated with a rust preventive compound, Houghton "Rust-Veto 344", or Rust-Oleum "R-9".

After above painting is completed, a lubricant compatible with the rubber seal shall be applied to surface of this seal and the mating metal surface to prevent bonding of the two surfaces during shipment and storage. Following application of the seal lubricant, the valve disk shall be placed in a slightly open position for shipment.

20. Valve Assembly:

All "buried" and "in-plant" valves shall be shipped fully assembled. "Submerged" valves shall be assembled in the manufacturer’s shop such that the torque tube is assembled to the valve shaft and the actuator adapter is mounted to the torque tube to ensure proper fit. The assembled valves shall be performance tested in accordance with AWWA C504. If the "submerged" valves are to be disassembled for shipment, the manufacturer shall match-mark all parts for assembly in the field by the OWNER. The torque tube connection to the valve shaft and the actuator shall also be "scribed" or otherwise marked to indicate relative orientation between the parts for field assembly.

21. Certification:

The manufacturer shall furnish a sworn statement that the inspection and all 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.

22. Acceptable Manufacturers:

Mueller
Pratt
Rodney Hunt
SPX/K-Flo
Val-Matic
M&H Valve Company

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.