STANDARD PRACTICES FOR ACTUATOR MOUNTING TO PROCESS VALVES

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1 The standard operation of quarter-turn Process valves is: Clockwise (CW) rotation of the stem Closes the valve Counter-Clockwise (CCW) rotation of the stem Opens the valve Note: Point of reference is the top of the valve/actuator. This operation is reflected in the manual operation of all valves. When automating a ball valve the actuator must use this same operational direction. Double Acting (DA) The standard aero2 Double Acting actuator has the following operation: A 1/4-18NPT 4x10-32UNF Air supplied to the A manifold port pressurizes the cylinder between the two pistons and will drive them outward, causing the output shaft to turn counter clockwise (CCW). Air supplied to the manifold port pressurizes the outside of the two pistons and will drive them inward, causing the output shaft to turn clockwise (CW). STANDARD ROTATION (Top View Cutaway) OPEN CLOSE [A] A [] In the standard configuration the two pistons are arranged so that when they are pressurized through port A the output drive will rotate (CCW/Open) Air supplied to port will provide the reverse of this (CW/Close). 1

2 Spring Return (SR) The standard aero2 Spring Return actuator has the following operation: Springs are added to the outside of the two pistons to provide an actuation force when there is a loss of air pressure. Air supplied to the A manifold port pressurizes the cylinder between the two pistons and will drive them outward, causing the output shaft to turn counter clockwise (CCW/Open). At the same time this action will compress the springs. When air is removed from the pressurized port A the springs will drive the pistons inward to rotate the output drive in the clockwise (CW/Closed) direction. A 1/4-18NPT 4x10-32UNF STANDARD ROTATION (Top View Cutaway) OPEN CLOSE [A] [A] Effectively this action is referred to as Spring-to-Close or Fail Closed When a process valve is required to fail to the open position it becomes necessary to re-configure the actuator so that the piston will provide the reverse rotation from the standard arrangement. (See Reverse Rotation on aero2 Actuators on the following page) 2

3 Reverse Rotation on aero2 Actuators Standard Configuration Air Stroke pushes pistons outward which are engaged shaft) to rotate CCW-OPEN. Spring Stroke pushes pistons inward which are engaged shaft) to rotate CW-CLOSED. Remove End Caps 2 Rotate pistons and re-insert. Note: efore engaging the piston (gear rack) with the pinion, back rotate the pinion gear by one tooth for proper orientation Remove indicator cap and use the wrench flats to assist with the removal and replacement of pistons. Loosen travel stops to allow pistons to travel outside of body. Remove Pistons: A low (3psi) pressure applied to port A will help expose the pistons for removal. Reverse Configuration 3 1. Air Stroke pushes pistons outward which are engaged shaft) to rotate CW-CLOSED. 2. Spring Stroke pushes pistons inward which are engaged shaft) to rotate CCW-OPEN. Reverse acting actuators are identified with the letter R At the end of the part number. Example: A2S-20-10R 3

4 Mounting the Actuator to a Process Valve Actuator Mounting Kit Process Valve Prior to mounting a Double Acting Actuator to a Process valve first determine the current valve position. If the Process Valve is Closed: Rotate the actuator to the full (Closed) clockwise (CW) position by: Remove the indicator cap and apply a wrench to the flats or Apply air pressure to the manifold port Check that the indicator shows the correct position when replacing it. If the Process Valve is Open: Rotate the actuator to the full (Open) counter clockwise (CCW) position by: Remove the indicator cap and apply a wrench to the flats or Apply air pressure to the manifold port A Check that the indicator shows the correct position when replacing it. Mount the actuator. Common practice is to mount the actuator so that the length of the cylinder housing is parallel to the process piping. As shown above. Prior to Mounting Spring Return Actuators Springs are used with pneumatic actuators to drive a Process valve to the desired position in the event of air lost. Which is sometimes called Fail Closed or Fail Open. The standard spring return actuator will fail to the close position (CW) when air is lost. When air pressure is applied to the manifold port A the actuator will rotate (CCW) to the open position. The valve is to be closed before mounting in the standard configuration. In the reverse spring return actuator, the valve is to be set in the open position to achieve the desired fail to open arrangement. (Reverse Rotation on aero2 Actuators is shown on the previous page) 4

5 Pneumatic actuators will use a solenoid operated valve to provide an electrical signal that initiates operation. This is known as a pilot valve. The standard pilot used by SVF is a NAMUR-style valve that mounts directly to the actuator air inlet manifold. Application Terms Energize When an electrical signal is applied to the solenoid of the pilot valve De-Energize When an electrical signal is removed from the solenoid of the pilot valve Process valves (SVF ball valves) are used in a variety of control applications. Users will often specify the operation of a valve using the following types of statements: Energize to close- When electrical signal is applied the Process valve will Close Energize to open- When electrical signal is applied the Process valve will Open These statements also infer that when the pilot valve is de-energized the process valve will rotate to the other/opposite position. Installing SVF (Double Acting) When the pilot valve is arranged as shown here (Red Manual override button on top) air pressure will be directed to manifold port A when the solenoid is energized. (Process Valve Opens)_Energize To Open (CCW) When De-Energized the air will be directed to manifold port (Process Valve Closes) _De-Energize To Close (CW) So for this Double Acting valve/actuator arrangement the operation is Energize to Open To Reverse this operation (Configure for Energize to Close) the pilot is removed and rotated 180 degrees so that: When the solenoid is energized. Pressure is now applied to manifold port (Process Valve Closes) _Energize To Close (CW) When De-Energized the air will be directed to manifold port A (Process Valve Opens) _De-Energize To Open (CCW) (See next page for proper orientation of pilot valve) 5

6 Pilot valve Arrangement according to its desired Energize position. Rotate 180 O Rotate 180 O Energize to Close (CW) Energize to Open (CCW) Installing SVF (Spring Return) When the pilot valve is arranged as shown here (Red Manual override button UP) air pressure will be directed to manifold port A when the solenoid is energized. (Process Valve Opens) _Energize to Open (CCW) When De-Energized the air pressure will be exhausted and the springs will drive the Process valve CW (Process Valve Closes) _De-Energize to Close (CW) So for this Spring Return valve/actuator arrangement the operation is Energize to Open <Fail Closed> To Reverse this operation DO Not Rotate the. Instead the Spring Return Actuator must be Reversed or reconfigured for Fail Open. See Reverse Rotation instructions above. For a Reverse Rotation Spring Return Actuator: When the solenoid is energized. The air pressure will be directed to manifold port A (Process Valve Closes) _Energize to Close (CW) When De-Energized the air pressure will be exhausted and the springs will drive the Process valve CCW (Process Valve Opens) _De-Energize to Open Position Indication The final step in the assembly is to check that the position indicator is reading correctly. The Yellow indicator on the lack/yellow cap should be: Parallel to the Process pipeline when the valve is Open Perpendicular to the Process pipeline when the valve is Closed 6