AMERICAN has incorporated significant and innovative design changes to help prolong service life for swing check valves in water and sewage service. Traditionally, swing check valves have been manufactured with bronze clapper arm shafts. Under severe service conditions where grit or sand has been present, these bronze shafts have a tendency to wear. AMERICAN Series 52-SC swing check valves incorporate the following design features to help increase service life.
Valve bodies and bonnets are made of gray iron. Generous clearances are provided between the disc circumference and body, as well as the clapper hub and body, which prevent the possibility of binding. Internal contours are specifically designed to provide a smooth flow passage and reduce head loss through the valve.
The entire clapper arm and disc assembly are easily removed through the bonnet opening while the valve is installed in the line.
The clapper arms are made of ductile iron. The clapper arm shaft hole and disc stud hole are bushed with bronze for wear and corrosion resistance.
Clapper arm shafts are made of high tensile strength, corrosion-resistant stainless steel.
Clapper arm shafts are retained and located in retaining plugs made of bronze. These plugs act as corrosion and wear-resistant bearings for the clapper arm shaft. The plug design incorporates straight threading, gasketing, and a hexagon wrench-hold to allow easy removal in the field for disassembly of internal parts from the valve.
Discs on check valves 4" and larger are made of gray iron with bronze disc rings securely fastened into grooves machined in the disc. The connection between the disc and clapper arm is designed with sufficient clearance to allow the disc to adjust to the seat.
Compliance with ANSI/AWWA C508
Certified to NSF/ANSI 372
Stainless steel clapper arm shafts
Full-diameter waterway
Solid ductile iron clapper arm
Bronze retaining plugs
Series 52-SC valves are available with the interior and exterior of the valve coated with fusion-bonded epoxy in accordance with ANSI/AWWA C550.
Check valves shall be manufactured from gray iron meeting or exceeding ASTM A126 Grade B.
Check valves are to comply with ANSI/AWWA C508, latest revision for use in water works service.
The rated working pressure of check valves 3 in. through 12 in. shall be 200 psig with a test pressure of 400 psig. The rated working pressure of check valves larger than 12 in. shall be 150 psig with a test pressure of 300 psig.
Check valves shall be Certified to NSF/ANSI 372.
The disc on check valves 4 in. and larger shall be made of gray iron with a bronze disc ring securely fastened into grooves machined in the disc.
Valve body shall a threaded-in bronze seat ring.
The connection between the disc and clapper arm shall be designed with sufficient clearance to allow the disc to adjust to the seat.
The clapper arm shall be made of ductile iron conforming ASTM A536 and shall exhibit a be bronze-bushed design to accommodate the disc assembly.
Clapper arm shaft shall be made of a high tensile strength, corrosion resistant stainless steel.
Clapper arm assembly shall mate with the valve body by using mounted bronze retaining plugs.
In applications requiring a lever and weight, or lever and spring design, where the clapper arm shaft extends outside the valve body, a double O-ring seal fully contained within the shaft bearing shall be provided. The lever and shaft design shall employ the use of a grease fitting for lubrication between the O-rings.
Disc shall not contact the body when the valve is in the full open position and shall swing clear of the waterway. Disc shall remain in the closed position when installed in a horizontal pipeline under no-flow condition.
Disc shall exhibit a clear-waterway as defined by ANSI/AWWA C508 and a Type 3 clear-waterway as defined by MSS SP-71.
Valves to be coated internally with a NSF 61 Certified coating Exterior shall be coated with a primer suitable for field application of a comparable top coat.
Valve to be designed for use in water and wastewater applications. Check valves equipped with lever and weight, or lever and spring, can be used in a horizontal pipeline, or in a vertical pipeline only when flow is in an upward direction. The lever orientation shall be field adjustable and must be positioned correctly for the installation.
Valves shall be equal to AMERICAN Flow Control’s Series 52-SC Swing Check Valve.
