Double Eccentric Butterfly Valve

Double Eccentric Butterfly Valve Specifications

The Double Eccentric Butterfly Valve adopts a double-offset disc design, which allows the disc to move away from the valve seat, thereby reducing operating torque and valve seat wear. Double eccentric butterfly valve operation can be done by gearbox and handwheel or electric, pneumatic or hydraulic actuators. Tested to comply with DIN3202, DIN2501 PN10/PN16 standards. This ensures the highest quality available. Dual offset disc design reduces torque and valve seat wear

The butterfly valve should be designed specifically for water plant applications and should be a double offset design. Zero and single offset butterfly valve designs are unacceptable. The valve should exceed the requirements of PN10. The valve should conform to the size and grade specified in the valve table. All valves should be airtight valves, the size is suitable for two-way water supply, full rated pressure

• Size: DN100-DN2000

• Pressure: PN6/PN10/PN16

• Standard:  DIN3202, DIN2501 PN10/PN16

• Pressure rating: Butterfly valve should meet ANSI Class 150B, Class 275B or Class 500B.

• Flange: The flange shall comply with ASME B16.1 Class 125.

• Disc length: flanged disc length should conform to AWWA C504-15 AWWA C519
  

Double Eccentric Butterfly Valve Materials

• Body :Ductile Iron, The entire valve body, excluding the shaft hole

• Seal : Ductile Iron+EPDM

• Stem : Stainless Steel 

• Valve label: The valve shall be equipped with mechanically fastened stainless steel stamped or engraved labels

• Disc: The disc shall be ductile iron ASTM A536 65-45-12 or ASTM A536 60-40-18. The disc should be fixed with 2205 duplex stainless steel pins and O-ring seals should be used to prevent media from entering the disc hub.

• Shaft: The valve shaft shall be stainless steel ASTM A240 2205 type duplex dual shaft.

• Resilient valve seat: The valve seat should be replaceable on site, and should be fixed to the valve disc by a 316 stainless steel valve seat fixing ring and fixed by 316 stainless steel fasteners. The elastic valve seat should be replaceable on-site, without stopping the valve. The elastic seat material should be EPDM. The valve shall have no leakage in both directions under full rated pressure, and conduct hydrostatic tests on both sides of the valve disc. On-site replaceable valve seats can be replaced without special skills or tools.

• Metal seat surface: The metal seat surface should be located in the valve body. The seat surface should be highly wear-resistant 316L stainless steel. The valve seat shall adopt the high-alloy double-surfacing welding process, and the minimum final surface thickness shall not be less than 5mm.

• Shaft seal: The shaft seal shall be suitable for the specified service. The shaft seal should be composed of multiple O-ring seals, which can protect the outer and inner diameters of the bearing at the same time. At least 8 O-rings should be used on each side of the disc. The elastomer material should be peroxide cured EPDM.

• Shaft bearings: The design and manufacture of valve thrust bearings should support the valve shaft and transmit disc force to the valve body, while minimizing friction and wear. The thrust bearings should be made of lead-free bronze and must be approved by NSF/ANSI. Rubber, Teflon or other plastic materials are not accepted as bearings.

Double Eccentric Butterfly Valve Characteristic

• Medium: Water, Waste Water，Oil
  

• Temperature: 0 to 100℃

• The shaft seal can be replaced under pressure for easy maintenance. EPDM seals ensure tightness from the inside to the outside, and NBR seals can prevent external impurities and fluids from entering.

• The butterfly valve is equipped with a locking device. If the gearbox needs to be replaced, the disc can be locked in the open/closed position.

• The low-friction PTFE bearing ensures low operating torque, and the protected shaft end ensures durability because no uncoated ductile iron surface is exposed to the medium.

• Two-way slim design

• Although valves of DN700 and above are marked with arrows indicating the preferred flow direction, these valves are bidirectional. We have also minimized weight to make handling easier and reduce stress on the environment.

• The drive you choose

• We provide any type of driver. Our standard options include IP67 gearboxes with handwheels for above-ground installation, IP68 gearboxes for underground services, and ISO input gearboxes for installation of electric actuators. In addition, we also provide extension rods, adapters and handwheels.