Instruction Manual For

ACTAIRE PILOT POSITIONERS

Series C46, C47, C48, C49

PRINCIPLE OF OPERATION

Refer to the proper Schematic Illustration for each Series of Positioner. With air pressure applied to the supply port of the Pilot, and the instrumental signal at mid-range, the unit is in force balance.

Series C46 (Figure 1)

The Series C46 Positioner is a direct, single acting output, force balance instrument having a tension spring feedback suitable for use with spring or fixed air pressure return linear Actuators. The instrument signal acts upon a Diaphragm Assembly creating a force toward the Pilot Valve. Opposing forces from the Suppression Spring and the Tension Range Spring counteract this force. The Stem is in its mid-position. An increase in the instrument signal causes an increased force toward the Pilot Valve and moves it open, increasing the output pressure to the Actuator. This increase causes the Stem to extend further and the force of the Tension Range Spring to increase. The Stem continues to extend until the increase in force of the Tension Range Spring equals the increase in the instrument signal above its mid-point. A decrease in the instrument signal from its mid-point causes the Diaphragm Assembly to move away from the Pilot Valve and open the Exhaust seat. This causes the Stem to retract and reduce the force of the Tension Range Spring. The Stem continues to react until the decrease in force of the Tension Range Spring equals the decrease in the instrument signal below its mid-point.

Series C47 (Figure 3)

The Series C47 Positioner is a direct, double acting output, force balance instrument having a tension spring feedback suitable for use with spring or fixed air pressure return linear Actuators. The instrument signal acts upon a Diaphragm Assembly creating a force toward the Direct Pilot Valve. Opposing forces from the Suppression Spring and the Tension Range Spring counteract this force. The Stem is in its mid-position. An increase in the instrument signal causes an increased force toward the Direct Pilot Valve and moves it open, increasing the output pressure to one (1) side of the Actuator. At the same time, the direct output pressure is applied to the Reverse Pilot Valve to open is Exhaust Seat, thus decreasing the reverse output pressure to the other side of the Actuator. This causes the Stem of the Actuator to extend further and the force of the Tension Range Spring to increase. The Stem continues to extend until the increase in force of the Tension Range Spring equals the increase in the instrument signal above its mid-point. A decrease in the instrument signal from its mid-point causes the Diaphragm Assembly to move away from the Direct Pilot Valve and open its Exhaust Seat. As the direct output pressure decreases, it causes the Reverse Pilot Valve to open, thus increasing the reverse output pressure. This causes the Stem to retract and reduce the force of the Tension Range Spring. The Stem continues o react until the decrease in force of the Tension Range Spring equals the decrease in the instrument signal below its mid-point.

Series C48 (Figure 2)

The series C48 Positioner is a reverse, single acting output, force balance instrument having a tension spring feedback suitable for use with spring or fixed air pressure return linear Actuators. The instrument signal acts upon a Diaphragm assembly creating a force away from the Pilot Valve. Opposing forces from the Suppression Spring and the Tension Range Spring counteract this force. The Stem is in its mid-position. An increase in the instrument signal causes an increased force away from the Pilot Valve and opens the Exhaust Seat, decreasing the output pressure to the Actuator. This decrease causes the Stem to retract and reduce the force of the Tension Range Spring. The Stem continues to retract until the decrease in force of the Tension Range Spring equals the increase in the instrument signal above its mid-point. A decrease in the instrument signal from its mid-point causes the Diaphragm assembly to move toward the Pilot Valve and moves it open. This causes the Stem to extend and increase the force of the Tension Range Spring. The Stem continues to extend until the increase in force of the Tension Range Spring equals the decrease in the instrument signal below its mid-point.

Series C49 (Figure 4)

The Series C49 Positioner is a reverse, double acting output, force balance instrument having a tension spring feedback suitable for use with spring fixed air pressure return linear Actuators. The instrument signal acts upon a Diaphragm Assembly creating a force away from the Direct Pilot Valve. Opposing forces from the Suppression Spring and the Tension Range Spring counteract this force. The Stem is in its mid-position. An increase in the instrument signal causes an increased force away from the Direct Pilot Valve and opens its Exhaust Seat, decreasing the output pressure to one (1) side of the Actuator. At the same time, the direct output pressure causes the Reverse Pilot Valve to open, thus increasing the reverse output pressure to the other side of the Actuator. This causes the Stem to retract until the decrease in force of the Tension Range Spring equals the increase in the instrument signal above it s mid-point. A decrease in the instrument signal from its mid-point causes the Diaphragm Assembly to move toward the Direct Pilot Valve and moves it open. As the direct output pressure increases, it causes the Reverse Pilot Valve to open its Exhaust Seat, thus decreasing the reverse output pressure. This causes the Stem to extends and increase the force of the Tension Range Spring. The Stem continues to extend until the increase in force of the Tension Range Spring equals the decrease in the instrument signal below its mid-point.

INSTALLATION

The following information is general in nature since each installation is designed for the particular Actuator being used. Drawing 154-002 and 154-001 show the location of two (2) mounting holes in the Positioner Bracket. The Positioner should be mounted on a sturdy adaptor bracket o at least 1/8" thickness or on a yoke or spacer bars. If the Positioner is to be used with a cylinder Actuator, the Positioner Bracket can be held on the side of the Actuator with two (2) Pipe Straps. The mounting in the vertical direction should be such that the distance from the Positioner mounting surface to the Stem connection in the retracted position is 4 7/8".

With the Positioner properly mounted, slip one end of the Tension Range Spring through the small hole in the end of the Post of the Positioner. Extend the Tension Range Spring and slip over the end of the Stem connecting rod. With the Tension Range Spring attached and the actuator in its retracted position, there should be a slight extension of the Range Spring.

ZERO ADJUSTMENT

Apply an air pressure to the supply port. Make sure this supply pressure does not exceed the safe pressure for the Actuator. Apply the minimum instrument air signal to the instrument port. Turn the Zero Adjust Nut clockwise increasing the instrument signal at which the Stem will just begin to move. Increase the instrument signal to its maximum valve. The Stem should retract the specified distance for the specified instrument signal range within plus/minus 5% of the specified range.

TROUBLESHOOTING

If it is suspected that the Positioner is not operating correctly, check the following:

1. Is the Positioner properly mounted? (Refer to "Installation" paragraph.)

2. Is the Positioner piped correctly?

3. Make sure supply pressure exceeds minimum pressure needed to move the Actuator.

4. Is there an instrument and output pressure at the Positioner? (If the Positioner is equipped with Pressure Gauges, check the output pressure reading on the Instrument Gauge and the out put pressure reading on the Output gauge. If the Positioner is not equipped with pressure Gauges, connect gauges to instrument and output ports and note readings.)

5. Is the Actuator working properly? (Disconnect the supply pressure from the Positioner and connect the supply pressure to the Actuator. Does the Actuator move full stroke?)

If additional help is needed, call our factory or return the Positioner to us for inspection.

WARRANTY

(a) Warranty:

(1) Seller warrants that, at time of shipment, the products manufactured or repaired by Seller and sold hereunder shall be free from defects in material and workmanship.

(b) Warrant Adjustment:

(1) Seller agrees to repair or furnish a replacement for, but not install, any product which within one (1) year from the date of shipment by Seller shall, prove defective within the above warranty. [Pneumatic Positioners shall be warranted for two (2) years from date of shipment.]

(2) If any defect within the warranty period appears, Buyer shall notify Seller immediately.

(3) No product will be accepted for return or replacement without the written authorization of Seller. Independent sales representatives of Seller are not empowered to authorize warranty returns. Upon such authorization and in accordance with instructions from Seller, the product will be returned to Seller, FO Seller's factory, shipping charges prepaid. Replacement made under this warranty will be shipped FOB Seller's factory at Seller's expense.

(c) Exclusions from Warranty:

(1) THE FOREGOING WARRANTY IS IN LIEU OF AND EXCLUDES ALL OTHER EXPRESSED OR IMPLIED WARRANTIES OF MERCHANTABILITY OF FITNESS FOR ANY PARTICULAR USE.

(2) Seller will not be liable for any special; or consequential damages or for loss, damage or expense directly or indirectly arising from the use of the products or any inability to use them either separately or in combination with any other equipment or material or form ant other cause.

(3) The warranty does not extend to any product manufactured by Seller which has been subjected to misuse, neglect, accident, improper installation, or to use in violation of instructions furnished by Seller.

(4) Products or components such as charts, tubes, cells, batteries, probes, and the like items which have limited life under normal usage are specifically excluded from this warranty.

(5) The warranty does not extend or apply to any product or component which has been repaired or altered at any place other that at a Seller factory, or by persons not expressly approved in writing by Seller, nor to any product or components, the serial number of which has been removed, defaced or changed.

(6) Components manufactured by any supplier other than Seller shall bear only that warranty made by the manufacturer of that product.