Emerson KEYSTONE FIGURE 79U - Keystone Actuator Maintenance Guide; Troubleshooting Actuator Power Loss; End Cap Tightening Torque Specifications

13
002 M5 3.2 4.3
003 M5 3.2 4.3
006 M5 3.2 4.3
012 M8 13.1 17.7
024 M10 26.2 35.5
036 M10 26.2 35.5
065 M12 45.2 61.3
090 M12 45.2 61.3
180 M16 108.5 147.1
KEYSTONE FIGURE 79 PNEUMATIC ACTUATOR
OPERATING AND MAINTENANCE INSTRUCTIONS
MAINTENANCE
If basic pneumatic system procedures are
maintained, the Figure 79 actuators will require
minimum maintenance for many thousands of
cycles.
TROUBLESHOOTING
If loss or reduction of power (in output torque)
occurs, take the following steps:-
1. Check air supply.
2. Check for o’ring leakage at the following
‘A’ Top and Bottom Bearing Seals
Apply pressure to PORT A and check with
soap/water solution for leaks at the top and
bottom bearing seals.
‘B’ Endcap Seals
Apply air pressure to PORT B and check
endcap joints for leakage.
‘C’ Piston Seals
Apply air pressure to PORT B and check
PORT A for leakage.
For access to ‘O’-ring seals in order to
replace, refer to Disassembly procedures
for appropriate models i.e. single or double
acting.
Note: Reduced stroke i.e. valve to which
actuator is fitted not travelling the required
stroke or “backlash” may be caused by an
incorrect fit between output bore and valve
stem.
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.
RECOMMENDED TIGHTENING TORQUES FOR END CAPS
Torque
Models Bolt Diameter (Nm) (lbs-ft)
STANDARD SPRING COLOR CODES
Spring Rating
Models 003S to 180S
End 1 End 2
40psi - 2.8bar Light Blue Light Blue
50psi - 3.5bar Light Blue White
60psi - 4.2bar White White
70psi - 4.8bar Light Blue/Dark Blue* White
80psi - 5.5bar Light Blue/Dark Blue* Light Blue/Dark Blue*
90psi - 6.2bar Light Blue/White* Light Blue/Dark Blue*
100psi - 6.9bar Light Blue/White* Light Blue/White*
* Nested (double) springs
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