KEYSTONE OPERATING AND SAFETY INSTRUCTIONS
RACK AND PINION, PNEUMATIC ACTUATORS
Before installation these instructions must be fully read and understood
1 INTRODUCTION
These products are manufactured and
supplied through a fully accredited ISO9001
quality system and all relevant national and
international standards are met as required.
Full after sales service and support, complete
with high quality replacement parts are
available on request.
2 PURPOSE
Actuators are available in a range of sizes
and are designed to be mounted to quarter
turn valves either directly or using the correct
mounting brackets / adaptors and sizing
procedures.
3 GENERAL PNEUMATIC SYSTEMS
RECOMMENDATIONS
To maintain maximum efficiency with this, or
other pneumatic actuators, we advise that the
following basic system recommendations are
followed:
a. Where air pipelines are subjected to
extremes of temperature, the system should
be fitted with air drying equipment.
b. Air control lines should be run to a
‘Recommended Piping Practice’ and should
not have “exaggerated” loops which may
trap condensate.
c. All pipe ends should be thoroughly cleaned
and deburred after cutting to ensure that
the pipeline is clear of cuttings.
d. If pipelines are hydraulically tested, then
the lines should be “blown down” with high
pressure air to clear all water, prior to
connecting lines to the actuator.
e. Where pipe fitting sealants are used, they
should be applied to the male threads only.
When applied to female threads, excess
compound can be transmitted into the
actuator control lines.
f. Where a system is dependent on Air Filter
Equipment, the air filters should be situated
in positions that allow easy access to
maintain and / or drain.
g. Where pneumatic valve positioners, or
pneumatic controllers are fitted to valve
actuator assemblies, oil mist lubricated air
should not be used unless the manufacturer
states specifically that the controllers are
compatible with lubricated air.
NOTE
Actuators are rated for air pressure in the range
40 psig (2.75 barg) to 120 psig (8.3 barg) and must not
exceed 150 psig (10 barg).
Emerson.com/FinalControl VCOSI-02266-EN 19/07
© 2017 Emerson. All Rights Reserved.
KEYSTONE OPERATING AND SAFETY INSTRUCTIONS
RACK AND PINION, PNEUMATIC ACTUATORS
4 OPERATION
Pneumatic actuators deliver torque through
the drive-shaft. Double acting actuators require
air for both open and closed travel modes.
A minimum of 5 psi can operate double acting
actuators.
For single acting spring return actuators, air
supply needs to overcome the force required to
compress the springs. This force is dependent
on the spring rating (typically 40psi up to
100psi maximum). Once charged, and the
springs are fully compressed, the system
is held in balance until the air pressure is
cut and allowed to decay (i.e. not locked off).
The (considerable) spring force is then released
and rotates the shaft very rapidly.
Note the following recommendations:
- Take due care and attention that the shaft is
not an ‘entrapment’ risk.
- It can be beneficial to manually check the
actuator by use of proper levers or gearboxes,
but use extreme caution on spring return
units to avoid bounce back.
- Similarly, any valve or accessory must be
properly and firmly / safely affixed to ensure
that the assembly package remains safe.
- Note that discs of butterfly valves, balls of
balls valves, etc, provide an entrapment risk
when operating the actuator out of the pipe.
Only properly trained and qualified personnel
should be allowed to bench test units and
assembled packages.
- Always use the correct size, grade and
method of fitting products together into a
package assembly.
- Always use correctly specified brackets and
couplings, when required, and ensure that
they are fitted securely.
- Improperly packaged units can rotate potential for dangerous backlash.
- Take great caution if working on units in
situ. Strict isolation of power supplies is
recommended.
- When working overhead, use only safe
practices and avoid any risk of falling /
dropping.
- Ensure all packages are properly supported
when fitted into the pipeline.
- Ensure all air connections are made properly
to be sealed tight and firmly affixed.
5 MAINTENANCE - DOUBLE ACTING AND
SINGLE ACTING UNITS
CAUTION
Remove all air pressure and observe normal
safety precautions including the use of eye
protection.
Always ensure that spring return actuators are
in the fail safe position before attempting any
maintenance.
Pay particular attention to this requirement when
manual operators are fitted.
For safety reasons DO NOT ‘Air Assist’ single
acting pneumatic actuators.
All maintenance operations must be
undertaken in accordance with the procedures
described in the relevant Installation, Operating
and Maintenance Instructions. The relevant
document reference is: Keystone F89 actuators.
6 TRAVEL STOPS
(WHEN RELEVANT TO THE MODEL)
WARNING
Under no circumstances must the travel stop
bolts be totally withdrawn from the actuator whilst
compressed air is being applied.
Internal travel stops must not be used for
manual override.
7 GENERAL INFORMATION
As standard, clockwise to close rotation, air
to Port A will rotate the actuator to the OPEN
position. Air to Port B will rotate the actuator to
the CLOSE position.
WARNING
For safety reasons, DO NOT ‘Air Assist’ single
acting pneumatic actuators.
Neither Emerson, Emerson Automation Solutions, nor any of their affiliated entities assumes responsibility for the selection, use or maintenance of any product.
Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.
Keystone is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation Solutions, Emerson
andthe Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.
T
he contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed
as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are governed by our terms and
conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time without notice.
Emerson.com/FinalControl
2
Loading...