PTFE Clamp Valve Engineering Specifications
Pressure Temperature Ratings Maximum pressures as a function of operating temperature for all PTFE Clamp Valves are as shown in figure 10. The vacuum rating of manual and electrically actuated PTFE Clamp Valves is 29.92" of mercury at temperatures from -20&degF to 350&degF for 6" and 8" valves and -20&degF to 400&degF for sizes 1" thru 4". Linear Actuated Valves should only be used in vacuum applications having fewer than 2000 projected open/close cycles or in applications where the valve will be stationary (either opened or closed) during the time when the vacuum is applied.
		Burst Pressure (min.) Valve Size (in.) @70&degF @400&degF 1 900 psi 600 psi 1 1/2 2 3 4 6 8
Flow Capacity Manual Valves Cv is a coefficient which relates the rate of fluid flow through a valve to the pressure drop across the valve. Valves with higher values of Cv will provide higher rates of flow for a given pressure drop. Cv values for PTFE Clamp Valves are dependent upon inlet pressure. Cv values shown above were determined with inlet pressures of 65 psi or higher.
Linear Actuated Valves FL is a coefficient which permits calculation of valve flow capacity at low inlet pressures.		FIG. 13 Valve Sizing Coefficient, Cv and Liquid Pressure Recovery Factor, FL for Linear Valves Valve Size Cv FL 1" 35 0.610 1 1/2" 112 0.420 2" 163 0.439 3" 396 0.330 4" 527 0.514
Inherent Flow Characteristics This chart shows the relationship of flow capacity to valve opening. The function is a straight line between 20% and 80% open. Curved transitions exist below 20% and above 80%.
Accurate Sizing Calculations This chart illustrates the effect of valve inlet pressure on Valve Flow capacity. The information is for service up to about 200&degF. For applications above this temperature the reduced flow due to vacuum conditions will be accentuated. Contact us for further information regarding details of the effect of temperature and vacuum.

Materials of Construction The Flexible Tube, Reinforcing Jacket and Teardrop inserts are manufactured only from virgin PTFE Fluorocarbon resin (Polytetrafluoroethylene). The resin meets the material requirements of ASTM D-1457 Type III and includes less than 1% of inorganic additives. The Body, Yoke and Compressor are ductile iron, ASTM A-395 (60-40-80) coated with corrosion resistant paint. All other operating mechanism components are corrosion resistant alloys except the Handwheel which is malleable iron, painted with corrosion resistant paint. Dimensions Refer to Dimensional Data for dimensions of Handwheel Operated Valves. Flange dimensions and face-to-face lengths are common to all versions of PTFE Clamp Valve. All valve flange dimensions conform to ANSI B16.42. The face-to-face dimensions in valve sizes through 4" conform to ANSI B16.10 Class 150. Performance Tests

Dimensional Data Design Details Manual Operated Linear Actuated