General Information

Linear (standard) - Equal increments of plug travel provide equal increments of flow change: for 10% of plug travel, the valve will pass 10% of its rated flow (Cv); for 20% of plug travel, the valve will pass 20% of its rated flow, etc.

Equal Percentage (optional) - Equal increments of plug travel provide uniform percentage of flow change: the same percentage increase in flow will occur when the plug moves from 30-40% of total travel as then the plug moves from 60-70% of total travel, etc.

The Cv (valve flow coefficient) method is an accepted way to size HI-FLOW™ Control Valves. By definition, Cv is the number of U.S. GPM of 60°F water that will pass through the valve with 1 PSI pressure drop. Basic formulas have been developed to express the flows of liquid, gasses and steam in terms of the flow coefficient Cv.

Once the required Cv is determined, selection of the proper size control valve can be made. It is recommended that the maximum capacity of a HI-FLOW™ valve should be 15% to 50% above the maximum process flow. And, the minimum required Cv must be within the available rangeability of the valve for proper control.

Selection of the proper LIN-E-AIRE© Pneumatic Actuator series is dependent on the type of HI-FLOWÔ valve selected and the action required. Assuming use of the standard Series 2000VA HI-FLOWÔ valve with push-to-close action: Direct Acting - select Air-To-Lower actuator; increasing pneumatic control signal closes valve, valve opens on loss of air. Reverse Acting - select Air-To-Raise actuator; increasing pneumatic control signal opens valve, valve closes on loss of air.

Although any LIN-E-AIRE© actuator size may be installed on any HI-FLOWÔ valve, from a practical standpoint, the maximum required operating force (based on available pneumatic control signal) should be selected. A wide variety of interchangeable springs are available for each actuator size enabling the selection of a standard actuator operating with custom control signal ranges for improved process control. Typically, the selection of actuator range spring will be performed by the factory as part of the normal manufacturing and calibration process. The chart on page 3 lists performance capabilities of standard valve packages to aid in economical selection.

Selection of the proper PRECISOR® Pneumatic Valve Positioner is dependent on they type of HI-FLOW™ valve3 and LIN-E-AIRE® actuator selected and the action required. Assuming use of the standard Series 200VA HI-FLOW™ valve with push-to-close action and a LIN-E-AIRE® Air-To-Raise actuator: Direct Acting - increasing pneumatic control signal opens valve, valve closes on loss of air; Reverse Acting - increasing pneumatic control signal closes valve, valve closes on loss of air.

1. Select the HI-FLOWÔ Control Valve Model No. to specify valve size and material.
2. Add LIN-E-AIRE© Pneumatic Valve Actuator Termination No. to specify size and control action.
3. Standard pneumatic control signal operating range is 3-15 PSI. If special range is required, add suffix -Z and specify on order, i.e. 2-10, 10-18, 6-30 PSI. etc.
4. Add suffix -A is a Pneumatic Valve Positioner is to be factory mounted and calibrated.
5. Add suffix -T1 (air-to-open valve) or -T2 (air-to-close) valve if a Current to PressureTransducer is to factory mounted and calibrated. Order separately.
6. For 2-Way valves, specify upstream pressure (USP). For 3-way valves, specify service and USP's Mixing: USPu and USP L are required; Diverting: USPc is required. EXAMPLE: 2001VA32-230-Z-A, 2-10 PSI, USP = 100 PSIG 100NF41-230, 2-10 PSI (factory installed)