Troubleshooting rotary actuators – Flowserve Valtek Spring Cylinder Rotary Actuators User Manual

Page 8

Failure

Probable Cause

Corrective Action

Actuator
operates,shaft
does notrotate

1. Broken actuator stem
2. Broken pivot pin
3. Sheared connection at splined lever arm

1. Replace actuator stem
2. Replace pivot pin
3. Replace splined lever arm or valve shaft

Jerky shaft
rotation

1. Cylinder wall not lubricated
2. Worn piston O-ring or load bearing ring,

allowing piston to gall on cylinder wall

3. Worn (or damaged) valve thrust

bearings,

4. Shaft bearings or packing followers

1. Lubricate cylinder with silicone lubricant
2. Replace O-ring or load bearing ring; if

galling has occurred, replace all damaged
parts

3. Disassemble and inspect parts; replace

any worn or damaged parts

High air
consumption or
leakage

1. Leaks in the air supply or instrument

signal system

2. Malfunctioning positioner
3. Leaks through O-rings or adjusting screw

gasket

4. Worn O-rings in sliding stem seal

assembly

1. Tighten connections and replace any

leaking lines

2. Refer to positioner’s maintenance

instructions

3. Replace O-rings or gasket
4. Replace assembly

Troubleshooting Rotary Actuators

Flowserve Corporation has established industry leadership in the design and manufacture of its products. When properly selected, this Flowserve
product is designed to perform its intended function safely during its useful life. However, the purchaser or user of Flowserve products should be
aware that Flowserve products might be used in numerous applications under a wide variety of industrial service conditions. Although Flowserve
can (and often does) provide general guidelines, it cannot provide specific data and warnings for all possible applications. The purchaser/user
must therefore assume the ultimate responsibility for the proper sizing and selection, installation, operation and maintenance of Flowserve prod-
ucts. The purchaser/user should read and understand the Installation Operation Maintenance (IOM) instructions included with the product, and
train its employees and contractors in the safe use of Flowserve products in connection with the specific application.
While the information and specifications presented in this literature are believed to be accurate, they are supplied for informative purposes only
and should not be considered certified or as a guarantee of satisfactory results by reliance thereon. Nothing contained herein is to be construed
as a warranty or guarantee, express or implied, regarding any matter with respect to this product. Because Flowserve is continually improving and
upgrading its product design, the specifications, dimensions and information contained herein are subject to change without notice. Should any
question arise concerning these provisions, the purchaser/user should contact Flowserve Corporation at any of its worldwide operations or offices.

For more information, contact:

For more information about Flowserve and its products visit
www.flowserve.com.

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