UWP Model , Ductile Iron Butterfly Valve – Conforms to AWWA C – DI Bodies translate into pure strength achieving three times that of Cast Iron alone. AWWA C Rubber-Seated Butterfly Valves. Document Language: English; Published By: American Water Works Association (AWWA); Page Count: The butterfly valves shall conform to the latest edition of AWWA-C Standard for Rubber Seated Flanged AWWA Butterfly Valves. The valves and actuators.
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Rubber seats applied to the valve body and penetrated by the valve shaft shall be adequately reinforced to prevent the seat from becoming inflated by pressure behind the seat. If an oversize actuator with no means of limiting torque is used, stop the actuator before the valve is fully opened or closed against stops and complete the operation aewa.
The cylindrical journal located in the body hubs that is used to support the valve shaft s and transmit disc forces to the valve body while minimizing friction and wear. Sincemost new valves installed for this type of service have been rubber-seated butterfly valves.
The number of turns to open and close for manual actuators d. Valves, hydrants and pipeline accessories for Water Works and Fire Protection. If the purchaser specifies a valve classification and fails to specify differential pressure or flow, actuator sizing shall be based on the pressure or flow requirement of the specified class rather than the most severe pressure and flow conditions listed in this standard.
Valve port diameter b.
A of this Foreword. Flange faces shall be protected from atmospheric corrosion. A welding process may be used to attach the mating surface to the disc or body. Epoxy coatings are more likely to result in a holiday-free surface. Components shipped unattached shall be adequately protected and identified for correct field assembly. Actuator housings, supports, and connections to the valve shall be designed with a minimum safety factor of 5, based on the ultimate tensile strength, or a minimum safety factor of 3, based on the yield strength of materials used.
A rubber ring around the swwa edge of the valve disc or the inside of the valve body to effect a seal against the metal seating surface when the disc is closed. The primary pressure-retaining structure of the valve that forms a portion of the pipeline and that has ends adapted for connection to the piping.
The design of the seat shall provide tight shutoff with flow in either direction, according to the tests required by Cc504.
This information should be provided according to items 5, 6, 7, and 24 of Sec. After testing, the actuator shall be completely disassembled and carefully examined for evidence of damage. Valve failure caused by faulty installation, improper operation, or maintenance in these systems could result in damage, downtime, and costly repairs.
These design conditions should be clearly specified by the purchaser. If severe service conditions exist, the purchaser should consider an epoxy coating. Homepage About Us Contact Us.
The manufacturer shall have previously manufactured rubber-seated AWWA butterfly valves of the same design for a minimum period of five years.
Valve discs shall be of a cast or fabricated design with no external ribs transverse to the flow. Ship valves with valve discs degrees open. The purchaser should consult with the manufacturers and, if appropriate, specify special requirements for these components. The provision of test records that are specified according to Sec. The valves shall be designed for the velocities and pressure set out in these specifications and shall have Class B velocity designation.
Two eye bolts shall be supplied with each valve.
Piping configurations that produce a non-uniform or turbulent flow pattern upstream of the valve can increase torque requirements, create damaging vibrations, increase head loss, adwa increase stresses in valve components. The records of these tests shall be made available to the purchaser if agreed on by the purchaser and manufacturer. The body and shaft seal shall be watertight.
Class B discs shall be ductile iron, fabricated steel, cast steel, or stainless steel. In the United States, authority to regulate products for use in, or in contact with, drinking water rests with individual states.
Four years later, inthe tentative standard was accepted as a standard.
The suitability of this type of surface depends, to a large awsa, on the quality of the manufactured product. After the cycle testing, the actuator shall be completely disassembled and inspected to determine whether or not excessive wear or permanent deformation affecting its function has occurred.
TESTING When rubber-seated butterfly valves are used to isolate sections of a line for testing, it is important to realize that these valves are designed or factory adjusted to hold rated pressure only. The valve shaft shall be fully enclosed with a housing, including where it connects to the actuator or bonnet extension.
The valve is closed when the edge of the awda is perpendicular to the flow way, open when parallel to the flow way, or used for throttling when positioned between open and closed. Bearings shall be designed for a pressure not to exceed awww published design load for the bearing material or one-fifth the compressive strength of the bearing or shaft material.
If these problems are anticipated, the purchaser should identify the maximum expected concentrations of these chemicals and other factors, such as pH and temperature awwwa, which may affect the corrosivity of these chemicals.
A in the Foreword. The liquid-penetrant examination of the test sample shall show no linear indications or porosity on, or adjacent to, the seating surface.
c54 Preferred-flow direction, if applicable Foreword Sec. With the disc in the closed position, air pressure equal to the valve class shall be supplied to the lower face of the disc for the full test duration.
Interior and exterior coating materials Sec. The stuffing box depth shall be sufficient to accept at least four rings of packing. Tolerance for valves 10 in.