The new D7 valve from leafield is a most wonderful thing for inclusion in Drop stitch panels such as raft floors, and stand up paddle boards. One of the best features that is not included in this link, or a picture of it, is the screen that keeps drop stitch threads out of the way of the seal. The O ring and the sealing surface around the top that does not use the black ring of the C7 makes this fantastic.
I personally do not want to stop using the C7, because I like the way the seal works in normal applications, because I have not used the D7 without the screen. The screen does increase inflation and Deflation time slightly.
We are using the D7 on some of our Paco Pads for those customers who just cannot live without this kind of valve. Note that some of our pad competitors use leafield valves, and so when they request this, we use the D7 because of the shorter length of the valve nut, which is the part that goes on the inside that you can not see. We recommend the screen be removed, because when using it on a pad, it really does not inflate or deflate any faster with the screen in place. This image shows the valve with the screen in place, and alos shows the O ring.
So here are some images of the D7 at work in Drop stitch fabric.
With the O ring sealing system we are able to cut a smaller hole and slip the nut inside of the Drop stitch and clamp directly to the inside surface of the Drop stitch. This reduces the area and the dome effect where there is no drop stitch under the valve opening.
Note that the back surface of the drop stitch is almost flat because of this application method. We still apply a backing to the valve sealing area, and we still seal the edge of that backing, as we always have. Sealing the edge reduces micro bubbling issues that happen at the edge of that backing material, regardless of the type of valve or the type of drop stitch that is used.
I think the engineers at Leafield have done a marvelous job with this. We can build drop stitch panels that hold air for incredible amounts of time, and they are stronger and more reliable than ever. Like this one.
Thank You LEAFIELD