Before installation, these instructions must be carefully read and understood.
YARWAY F881, F883 AND F884 FLOAT AND THERMOSTATIC STEAM TRAPS
SUMMARY OF INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
© 2019 Emerson. All rights reserved. VCIOM-12937-EN 19/05Emerson.com/FinalControl
INSTALLATION POSITION
CORRECT INSTALLATION WRONG INSTALLATION
INSTALLATION PROCEDURE
• Check that the product is suitable for the
intended application (i.e. materials and
pressure/temperature ratings).
• Remove plastic covers from end connections.
Be sure that the equipment is installed
according to the arrow for Inlet/Outlet
designations.
• Ensure that the jointing material does not
block or enter the trap.
• If Teflon tape is used (for threaded
connections), avoid rolling it till the edge.
• Install the steam trap at a point where
condensate tends to accumulate.
• A Strainer should be installed upstream of
the trap. The strainer must be installed with
the sieve sideways.
• Take the necessary precautions to prevent
damage to this product due to thermal
expansion and other external sources of
stress.
• The steam trap pipework should be properly
supported and free from strain and it should
not be subjected to undue surges of pressure.
MAINTENANCE
• The steam trap must be checked at least
once a year (i.e. validate its operation and
clean the internals).
• When reassembling, make sure all gasket
faces are clean. Always use a new gasket.
Tighten cover bolts uniformly in a diagonal
sequence.
• Maintenance should proceed as follows:
1. Isolation valves should be closed.
Pressure and temperature should be
atmospheric.
2. Remove the type of connections used.
3. Execute the maintenance work.
4. Replace and tighten the connections (don’t
forget to replace the gasket).
5. Consider the start-up conditions.
2
YARWAY F881, F883 AND F884 FLOAT AND THERMOSTATIC STEAM TRAPS
SUMMARY OF INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
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Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.
Yarway is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation Solutions, Emerson
and the Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.
The 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.
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For additional information, please visit: https://www.emerson.com/en-us/catalog/yarway-p001409
RATINGS AND SPECIFICATIONS
Specification Series
Specification
Series
F881 F883 F884
Operating Principle Mechanical
Type Float and Thermostatic
Size ½" - 1" 1"-HC 1½" - 2" 2"-HC ½" - 1" 1"-HC 1½" - 2" 2"-HC ½" - ¾" 1" 1"-HC 1½" - 2"
Maximum Operating Pressure (psig) 203 464 203
Maximum Operating Temperature(°F) 388 482 388
Nominal Flow (lb/h at 100 psi; near
saturation, unless otherwise noted)
1090 3524 11894 30286 1090 3524 11894 30286 726 1090 3524 11894
Maximum Back Pressure (% of inlet;
based on absolute pressure)
99
Minimum Differential Pressure (psi) 1.5
TROUBLESHOOTING CHART
Issue Possible Reason Solution
Continuous steam discharge.
Damaged seat.
Incorrect installation.
Substitute seat.
Check the installation position.
Inadequate condensate discharge.
Obstructed strainer.
Inadequate pressure differential.
Excessive back pressure.
Damaged float.
Clean accordingly and identify the
possible reason for contamination.
Check the steam trap differential
pressure and substitute.
A larger steam trap end
connection may be required.
Replace.
Temporary condensate
accumulation.
Steam blocking.
Downsizing.
Use a steam trap with SLR.
Check maximum flow rate (during
startup).
Slow intial startup.
Damaged air eliminator.
The air flow is too high for thetrap.
Downsizing.
Replace.
Install an additional aireliminator.
Check maximum flow rate (during
startup).
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