GENERAL INFORMATION
Adjustable Port Valves are ideal for automatic control of oxygen flow to meet the requirements of modern instrumentation in combustion systems. The adjustable port feature permits sizing the valve to fit the application, after valve has been installed. Linkages can be adjusted for full or limited valve travel.
For a valve operated by a modulating type control, either a linear or an equal percentage characteristic is preferred for most applications. These characteristics are shown in Figure B, together with two curves indicating very common but usually undesirable
flow patterns: In their lower parts, change of flow is too fast, causing an "over correction;" while at the upper end there is practically no flow change in response to valve movements.
Shape of a flow curve depends (1) on valve area characteristic, and (2) on size of valve port relative to downstream resistances
(piping, orifices, and burners), the sum of which is difficult to predict. An Adjustable Port Valve solves the problem. Its linear area
characteristic permits proper "sizing" of valve after installation without involved calculations.
Recommended procedure is to open valve control handle and valve curtain wide, then close curtain until pressure drop across
valve is 1⁄5 to 1⁄6 of total system pressure drop. Flow characteristics shown as solid lines in Figure B can be realized with full valve stroke, enabling desired flow response to movements of the control motor.
1010A-C Valves are designed for oxygen service up to a maximum pressure of 125 psi. All valves are for throttling control
only and not for tight shutoff. Bodies of all 1010A-C valves are brass. All cores and curtains are Monel and the shafts are stainless steel.
The packing is Teflon and all gaskets are Fluorocarbon rubber (Viton). Valves are cleaned for oxygen service, lubricated with PFPE lubricant and shipped in a sealed plastic bag to keep clean. See Sheet 1008A Instructions for lubricating instructions. Dimensions are the same as 1008 Valves, only materials of construction are different. (See pages 4-6) 1008A-C valves are designed for oxygen service up to a maximum pressure of 50 psi and pipe velocities up to 100 FPS. The bodies of 1008A-C valves are ductile iron. All cores and curtains are 316L stainless steel and the shafts are SST. The rest of the valve is constructed and lubricated the same as the 1010A-C.