Abstract: A valve apparatus. The valve apparatus is disposed within a well so that an annulus is formed between an outer portion of the valve and an inner portion of the well. In one preferred embodiment, the valve apparatus comprises an outer mandrel containing an annulus port; an inner mandrel slidably disposed within the outer mandrel, and wherein the inner mandrel contains a production and equalizing port. The valve contains a seal assembly so that pressure from the annulus is isolated from the inner portion of the inner mandrel. In one preferred embodiment, the seal assembly comprises: a first header seal; a first seal ring, abutting the header seal, for sealing with the outer portion of the inner mandrel; a follower seal abutting the seal ring; a second seal ring, abutting the follower seal, for sealing with the outer portion of the inner mandrel; a second header seal; and an equalizing seal abutting the second seal ring.

Abstract: A valve apparatus. The valve apparatus is disposed within a well so that an annulus is formed between an outer portion of the valve and an inner portion of the well. In one preferred embodiment, the valve apparatus comprises an outer mandrel containing an annulus port; an inner mandrel slidably disposed within the outer mandrel, and wherein the inner mandrel contains a production and equalizing port. The valve contains a seal assembly so that pressure from the annulus is isolated from the inner portion of the inner mandrel. In one preferred embodiment, the seal assembly comprises: a first header seal; a first seal ring, abutting the header seal, for sealing with the outer portion of the inner mandrel; a follower seal abutting the seal ring; a second seal ring, abutting the follower seal, for sealing with the outer portion of the inner mandrel; a second header seal; and an equalizing seal abutting the second seal ring.