Double eccentric butterfly valves

Available with three different seat designs

The integral seat design has a machined and epoxy- coated ductile iron seat integrated into the body. The stainless steel seat design is available in two variants: one with a replaceable seat ring of stainless steel sealed with an O-ring to avoid leakages under the seat ring and one with a welded stainless seat machined and polished to give a smooth surface.

Unique connection between disc and shaft

The disc and shaft are connected by means of a key and a keyway. The key is secured with two set screws to prevent fluttering caused by flow velocity and necessary play in the key and keyway connection. In the large dimensions the disc is secured with two stainless steel drive dowels, with key and keyway as back-up.

High-performance disc design

The disc is engineered to minimise pressure loss via CFD simulations. The disc seal is shaped to secure fixation in correct position providing a very reliable function. The superior rubber quality allows it to reduce the amount of rubber which ensures low closing torques. The EPDM sealing is approved by DVGW, KIWA and WRAS.

Shaft design

The shaft sealing is designed to be replaceable under pressure to enable easy maintenance. The EPDM seals secure tightness from inside and out, and NBR sealings protect against impurities and fluids from outside.

Low friction PTFE bearings contribute to low operating torques and the protected shaft ends secure durability since there are no uncoated ductile iron surfaces exposed to the media.

Our double eccentric butterfly valves can be delivered with a locking device which makes it possible to lock the disc in open/closed position if gearbox replacement becomes necessary.

Bi-directional and slim design

AVK butterfly valves are designed for bi-directional flow, even though valves from DN700 and up are marked with an arrow indicating the recommended flow direction. We have also minimized the weight to make handling easier and to put less strain on the environment.

Flexible actuation options

We provide any type of actuation. Our standard options are IP67 gearboxes with handwheel for above ground installation, IP68 gearboxes for buried service, and ISO-input gearboxes for electrical actuators mounting. Additionally, we supply extension stems, adaptors and handwheels. 

Third party approvals

AVK double eccentric butterfly valves are approved by DVGW (DN150-1200), Kiwa (DN200-800) and WRAS (DN900-1200, smaller dimensions on request). For larger dimensions all components are approved for use with drinking water.

Where are double eccentric butterfly valves used?

Double eccentric butterfly valves are most often used in water supply applications below ground as an alternative to gate valves. They require less bury depth when installed underground and typically, they are more cost-effective, especially in the large dimensions, compared to gate valves. They can of course also be used above ground.