XLC 470
8
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Regulations of pilots has to be carried out slowly to avoid unwanted pulsations and
pressure surges. Always leave enough time for the system to balance, in case of
doubts and problems allow for some flow through the by-pass to stabilize the line and
call CSA technical support.
Set up
For the proper set up of XLC 400 Mod. 470 reader is advised to use the following points (rif. picture
1 on page 4).
Make sure the isolation ball valves of the circuitry (2-3-4-5) are fully open
The valve is at first isolated from the main line as both sectioning devices, upstream and
downstream, are closed.
Unless a specific setting has been required in the order remove the hood from the pilot (7)
and turn anticlock wise the screw to decrease the spring force in the cover almost
completely. The static level of the tank depends on the pilot setting and it is proportional to
the charge of the spring. Regulation charts are available on request.
Slowly operate on the upstream gate valve to open it by 30 %, leaving the downstream
sectioning device completely closed.
Pressure will enter
the valve’s body, circuitry and bonnet pushing down the diaphragm and
mobile block against the obturator and inducing the valve to the closing position still
ensuring some flow towards the tank.
Should the total closure be needed user is invited to close the ball sectioning valve (3)
Remove the air entrapped in the bonnet, during the operation, by means of the air release
device located on top of the position indicator (8) leaving it flowing for at least 20 seconds.
Open completely the upstream gate valve
Open the ball valve (3) if it has been closed
Slowly open the downstream gate valve, to a maximum of 40% of the stroke, to generate
some flow through the valve and give the valve enough time to react, this depends on how
big is the system downstream and on the variations in demands.
Having decompressed, the spring as per indications mentioned above unless a specific
setting was required in the order, the XLC 470 control valve will tend to maintain the level of
a tank to a very low level therefore interrupting the supply (if lower than the current value
sensed on the pressure port 5)
Slowly act on the regulation screw on the pilot (7) turning it clockwise, thus increasing the
required level of the tank
The valve will open accordingly generating some flow
Open completely the downstream gate valve
