Data Sheet for Product

Technical Instructions Flowrite™ AP 599 Series 12-inch Pneumatic Valve Actuator
Document No. 155-162P25
June 14, 2019
Information in this publication is based on current specifications. The company reserves the right to make changes in specifications and models as
design improvements are introduced. Flowrite is a trademark of Siemens Industry, Inc. Other product or company names mentioned herein may
be the trademarks of their respective owners. © 2019 Siemens Industry, Inc.
Siemens Industry, Inc.
Smart Infrastructure
1000 Deerfield Parkway
Buffalo Grove, IL 60089-4513
USA
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Document No. 155-162P25
Printed in the USA
Page 6
Spring Adjustment
With the actuator in an upright position and the stem visible as shown in Figure 3,
use a 1-1/16 inch open-end wrench to turn the adjustment screw.
• Normally Open Valves: To increase the start to close pressure, turn the
adjustment screw from right to left. To decrease, turn the adjustment screw from
left to right.
• Normally Closed Valves: To increase the start to open pressure, turn the
adjustment screw from right to left. To decrease, turn the adjustment screw from
left to right.
NOTE: As the line pressure differential across the valve increases, the spring
span will increase.
Figure 3. Spring Adjustment.