172-65169MA-08 (MC-COS Multi-control Valve) 28 May 2010
23
Disassembly
NEVER apply direct heat to the float. The float may explode due to
increased internal pressure, causing accidents leading to serious injury
or damage to property and equipment.
WARNING
Use hoisting equipment for heavy objects (weighing approximately
20 kg (44 lb) or more). Failure to do so may result in back strain or other
injury if the object should fall.
CAUTION
When disassembling or removing the product, wait until the internal
pressure equals atmospheric pressure and the surface of the product
has cooled to room temperature. Disassembling or removing the
product when it is hot or under pressure may lead to discharge of fluids,
causing burns, other injuries or damage.
CAUTION
It is a recommended practice to dismantle and inspect the MC-COS once a year for
preventive maintenance purposes. It is especially important to do so immediately
after the initial run of a new line or before or after equipment such as a heater is out
of service for a long period of time.
(Installation, inspection, maintenance, repairs, dismantling, adjustment and valve
opening/closing should be carried out only by trained maintenance personnel.)
Before Dissassembly
Remove all steam from the piping (both upstream and downstream). Set the value of
the valve operation signal from the controller to the MC-COS to 0% (4mA) or less.
The drive section will operate in response to the valve operation signal, with the
adjustment screw moving counterclockwise and up to close the valve. Wait for the
body to cool before attempting to remove the MC-COS from the line. Turn OFF the
power to both the drive section and the valve operation signal (controller) and
disconnect the cables. Then remove inlet and outlet flange retaining bolts and nuts to
permit removal of the MC-COS. Secure the MC-COS in a vise to perform the
inspection.
Disassembling the Adjustment Section
Loosen the adjustment screw completely and remove
the bolts from the spring housing. Grasp the mounting
plate and lift the spring housing straight up and off.
Having removed the spring housing, you will see the
diaphragm retainer, coil spring, bearing and spring retainer.
Check to make sure there is no dirt, etc. inside the
spring housing, and check for seizure or any damaged
screw threads. Then, using a wrench, turn the
adjustment screw back and forth. Check to make sure
that it turns smoothly. A slight torque is necessary since
the motor has a rotational load.
If the adjustment screw
does not rotate smoothly, contact TLV immediately.
Note: Do not remove the drive section cover. The
drive section, which contains precision
electronic components, is maintenance-free.
Bolt
Spring
Housing
Bearing
Spring
Retainer
Coil
Spring
Diaphragm
Support
Adjustment
Screw
Mounting
Plate