The clamping mechanism consists of a compressor which travels down a stem with rotation of the handwheel or power operator, and a yoke which travels up the stem at the same time. Together these components clamp off flow bubble-tight (figure 3.) Linear Actuated Clamp Valves utilize two similar compressors rather than one compressor and a yoke. There is another very essential element - so vital that it is called the heart of the valve. This consists of Teflon inserts - teardrop shaped in cross-section - one on each side of the Teflon tube. The sides of the tube are gently wrapped around the teardrop inserts and then held firmly in place by radius clamps (figure 4).

This design prevents the tube element from being overstressed. All flexing takes place on the center line of the valve between the teardrops. Kinks, creases and pinching are eliminated, thus insuring long life for the valve. The radius clamps are connected to the yoke and to the compressor by means of links and link pins. These components, working together provide a scissor-jack action which pushes the tube element inward during the opening cycle and pushes it outward during closing (figures 5 & 6).

Another unique feature of the Clamp Valve is the use of four lift forks imbedded top and bottom in the tube element on each side of the clamp (figure 7). They act as powerful fingers which work with the links and link pins to pull the sealing surfaces apart even under full vacuum conditions. All of the operating parts are encased in a ductile iron body coated with corrosion resistant paint (figure 8).

Standard ANSI Class 150 flanges on the valve body, over which the ends of the tube element are flared permit it to be easily bolted into a pipe line. Because the valve is symmetrical and completely bi-directional, either end can be placed upstream.