VNM shaker screens are more and more popular. We also always suggest users change their Cobra series screen to be VNM series screen.
The primary difference between the screens is the frame. All steel replacement for Venom screens use larger tubing on the perimeter. The tubing used in Venom screens is stiff enough to keep the screen against the bed.
The former perimeter tubing used in replacement for Cobra screens is not stiff enough to keep the screen against the bed. To overcome this, additional tubes are run the width of the screen. The Cobra shaker screens need support from the shaker bed contacting additional support tubes in order to get enough stiffness. Even with the additional tubing, there is enough movement against the Urethane deck rubbers to wear them out. If these deck rubbers are not replaced when they begin to wear, the support of the deck will also wear. Once the deck is worn, the speed of deck rubber wear will increase. Since Replacement for Venom screens don’t use deck rubbers under the center of the screen, and since they do not cause wear to center supports of the basket, they are cheaper to
run. The savings from not having to use interior deck rubbers and not having to repair interior deck supports, quickly recoups the cost of purchasing the wedges required to run the replacement for Venom screens.
The addition of tubes running the width of the replacement for Cobra screens causes a different flexing motion in the panel. This difference causes solids to tend to convey slower across those locations of the screens. The replacement for Venom panels flex between the tubes running in the direction of flow and that motion is only slowed at the perimeter.
Decreased conveyance causes more solids retention yielding higher weight on the screen resulting in a faster deterioration of the wire cloth.
If this were not the case, why are most of the Cobra/King Cobra machines fitted with Venom screens?
When making the change, you do not have to waste the Cobra screen inventory that you currently have. The screens can be used until your inventory of these is gone. I would leave the interior deck rubbers on machines that are using both types of screen until you are out of the replacement for Cobra screens because these screens will not function without center support.
Why does Aipu shaker screen want its’ customers to change? We just don’t want our reputation to be marred by relying on a obsolete design. We also don’t want phone calls for poor screen life that we know will be caused by worn decks and crown rubbers when it is completely avoidable