Transmark Fcx’s new Twin Seal valve is an alternative to the traditional two valves system with one double-seated bubble-tight valve. Seal abrasion is avoided by engineering the Twin Seal so that when it is in the open position the seals are completely out of the flow. Turning the hand-wheel clockwise initially rotates the plug 90 degrees, aligning the seals with the body-sealing surface. Turned further the plug lowers, forcing the seals against the body, a secondary metal to metal seal also forms on both sides of each seal. Closed, the seals compress against the flow ports forming bubble tight seals both up stream and down stream. This design of valve negates the constant seal wear by using two independent seating slips mounted separately on a taper plug by dovetails. During the closing of the valve the wedging action of the plug forces the seating slips onto the valve body. During opening, the dovetails pull the slips away from the body. Twin Seal valves are available in sizes 2” to 36” class 150-1500.
