MUELLER DOUBLE DISC CHECK VALVE

SPECIFICATIONS

• Model : 71AHH-6-H • Body Material : Cast Iron ASTM A126-B • Disc : 316 Stainless Steel • Seat : EPDM • Spring : 316 Stainless Steel • Working Pressure : 200 PSI WOG @ 100 F • Connection :  ANSI 125 / JIS 10 K

SERVICE RECOMMENDATIONS

• These elastomer seated valves are designed for liguid and gas service to prevent surge and water hammer due to flow revarsal. Specially designed springs close the discs before flow reversal can occur. FEATURES • The extremely short face-to-face dimension and compact design of this valve allow in- stallation and service in tight spaces. The specially designed torsion springs exert a lifting motion on the discs to prevent excessive wear of the “heel” area of the elastomer seats. On site service may be done without special tools. The independent, dual shaft design allows interchangeability of shafts. The stop shaft stabilizes the discs during high flow rates.

ORDERING INFORMATION

• We require all pertinent conditions relating to the proposed use of the check valve. They are: operating pressure, temperature, flow rate or velocity and type of pump in the system. If corrosive fluids are involved we shoule be advised. Consult factory for appli- cations such as pump suction and volatile liquid handling.

INSTALLATION

• Sure CheckTM is equally effective for vertical or horizontal flow. Horizontal flow shafts should be oriented vertically. Consult factory for downward vertical flow. Sure CheckTM is designed to fit inside ANSI bolt circles. We strongly suggest the installation of a strainer ahead of the pump to ensure protection of the pump and the working parts of the valve.

CONSTRUCTION

• #71 Sure CheckTM is normally furnished with cast iron (ASTM A126-B) bodies. #71U Sure CheckTM is furnished with ductile iron bodies. The disc material for sizes through 5″ (125mm) is bronze (85-5-5-5, ASTM B62); sizes 6″ (150mm) through 54″ (1380mm) can be supplied with nickel coated ductile iron or bronze discs. Discs in 316 stainless steel are also available in all sizes. Standard shaft and spring material is 316 stainless steel. The elastomer seat normally furnished is Buna-N. Consult factory for high tem- perature service.

TESTING

• The shell and seat of each valve are hydrostatically tested in accordance with ANSI standards.

APPROVALS

• Sure CheckTM Valves conform to ANSI specifications, API specification, Factory Mutual requirements and U.L. requirements. Consult factory about specific models and sizes.

MATERIALS

• Body- 71: Cast Iron ASTM A 126-B 71U : DuctileIron • Disc- Bronze ASTM B62, Ductile Iron ASTM A536 316 Stainless Steel ASTM A351 Grade CF8M D18. • Seal Buna-N / EPDM / Metal