Asco 8401 Series Installation And Maintenance Instructions

Installation & Maintenance Instructions
2 POSITION, 3-WAY AND 4-WAY FUNCTION
ADAPTER BASE MOUNTED SOLENOID PILOTED VALVES
FOR KEYSTONE, NAMUR AND GH-BETTIS AIR ACTUATORS - 1/4I NPT
NOTICE: See Installation and Maintenance Instructions, Form No.V6844 - Section 1 of 2 for detailed instructions.
Continued from Form No. V6844 - Section 1 of 2
Solenoid Temperature
Series 8401 valves are supplied with coils designed for con
tinuous duty service. When the solenoid is energized for a
long period, the solenoid coil becomes hot and can be
touched with the hand for only an instant. This is a safe op
erating temperature. Any excessive heating will be indi
cated by the smoke and odor of burning coil insulation.
MAINTENANCE
WARNING: To prevent the possibility of
personal injury or property damage, turn off
electrical power, depressurize valve, and
vent fluid to a safe area before servicing the
valve.
NOTE: The entire solenoid valve must be removed from the
actuator for inspecting, cleaning, and/or rebuilding. It is not
necessary to solenoid valve for coil or pilot valve replace
ment.
Cleaning
All solenoid valves should be cleaned periodically. The time
between cleaning will vary depending on the medium and
service conditions. In general, if the voltage to the coil is cor
rect, sluggish valve operation, excessive noise, or leakage
will indicate that cleaning is required. In the extreme case,
faulty valve operation will occur and the valve may fail to
shift. Clean strainer or filter when cleaning the valve.
Preventive Maintenance
Keep the medium flowing through the valve as free from
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dirt and foreign material as possible.
While in service, the valve should be operated at least
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once a month to ensure proper operation.
Causes Of Improper Operation
Faulty Control Circuits: Check the electrical systems by
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energizing the solenoid. A metallic click signifies that the
solenoid is operating. Absence of the click indicates loss
of power supply. Check for loose or blown fuses,
open-circuited or grounded coil, broken lead wires or
splice connections.
Burned-Out Coil:
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Replace coil as necessary: see Coil Replacement check
supply voltage; it must be the same as specified on
nameplate.
e
ASCO Valves
Check for open-circuited coil.
MCMXCVII All Rights Reserved.
Low Voltage: Check voltage across the coil leads. Voltage
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must be at least 85% of nameplating rating.
Incorrect Pressure: Check valve pressure. Pressure to
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valve must be within range specified on nameplate.
Excessive Leakage: Disassemble valve, and install a
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complete ASCO Rebuild Kit and pilot valve.
Coil Replacement
1. Disconnect coil lead wires, then remove retaining clip or
cap.
2. Slip coil off the plugnut/core tube sub-assembly.
CAUTION: When retaining clip disengages, it
springs outward.
3. Install new coil and replace retaining clip or cap. Torque
retaining cap to 10 - 12 in-lbs [1,1 - 1,3 Nm] with a
21/32I socket.
4. Make electrical hookup; see Wiring section.
Valve Disassembly
5. Disassemble valve in an orderly fashion. Use exploded
views for identification and placement of parts.
6. Disconnect coil leads or remove coil from solenoid pilot
valve. See Coil Replacement section.
7. Remove entire valve with flow gasket from actuator as
follows:
Namur Actuator - Remove two socket head cap
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screws using a 4 mm hex key wrench.
Keystone Actuator - Remove four socket head cap
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screws, one from each corner using a 5/32I hex key
wrench.
GH-Bettis Actuator - Remove four hex head
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machine screws, one from each corner using 5/16I
wrench.
8. Remove two pilot valve screws, bracket (if present), pilot
valve assembly, and two pilot valve gaskets from valve
body.
CAUTION: When removing base screws hold valve
body/adapter base assembly together to prevent
parts from disengaging prematurely.
Page 5 of 8 (Section 2 of 2)
Printed in U.S.A.
50-60 Hanover Road, Florham Park, New Jersey 07932
SERIES
8401
Form No.V6844R2 - Sec. 2
(Section 2 of 2)