An EVR valve is a type of flow regulator that is used in suction lines and liquid lines to control the flow of fluid. The valve has a central bore that allows air to pass through while the armature is in a closed position. This is done by a bobbin that is shaped in a non-magnetic nylon-tape material. This enables a smooth axial movement. The bobbin also acts as an air passageway.
An EVR valve is comprised of a solenoid assembly and a bobbin that are secured to an upper valve housing that contains a vacuum regulator. This assembly can be separated and replaced as needed. This simplifies service and minimizes inventory. In addition, there are service kits available for EVR valves. These kits include parts for the solenoid valve and the vacuum regulator. The vacuum regulator can be a standalone device or interconnected with tubing.
The EVR valve is a compact design that provides the advantages of a conventional flow regulator. It is suitable for use in both liquid and fluorinated refrigerants. It is designed for media temperatures up to 221 def. The valve’s low radial forces provide a precise delivery of the prosthesis, as well as an extended sealing skirt. It features a smaller insertion profile, which is useful for patients with less accessible iliofemoral arteries. It also reduces the risk of paravalvular leaks.
Aside from reducing the risk of paravalvular leaks, the EVR valve is designed to have a lower rate of mild paravalvular regurgitation. It has the capability to deliver the prosthesis at its intended position 3-5 mm below the native annulus. This allows for more optimum positioning of the valve. It also prevents the need for the EVR valve to be recaptured. This pinch valve manufacturers feature is often utilized to avoid suboptimal valve deployment.
The new generation EVR valve is composed of a self-expandable nitinol frame that features a cylindrical shape on the lower part of the prosthesis. It has an extended sealing skirt that is slightly cranial to the native annulus. It also has a lower profile that allows transfemoral access.
The EVR prosthesis has an 18F outer diameter. This size is small enough that it is compatible with the femoral artery and the iliofemoral vessels, thereby decreasing the number of vascular complications. The insertion profile is also slightly cranial to the native annulus, providing a more consistent radial force.
The new EVR prosthesis has an optional recapture option. This is particularly beneficial for patients with a deep position of the prosthesis within the left ventricular outflow tract. It also permits the prosthesis to be delivered at its intended position 3-5 mm below its native annulus, which can prevent the need for the valve to be recaptured.
An electronic flow regulator can be adapted to accommodate the net build EVR valve. The “start-to-flow” duty cycle is set to 30%. This is a linear function that is regulated to match the vacuum output of the EVR valve.