Azbil Micro Flow MQV0002, Руководство пользователя

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3-1
Chapter 3. MOUNTING AND WIRING
WARNING
Never allow gases that are within explosive limits to pass through this device. Doing so might
result in an explosion.
If the MQV is to be used for oxygen, make sure that it is a model designed for oxygen use. Even
if a device is designed for oxygen gas, do NOT use it for oxygen gas if it has been used for some
other gas even once. Oil contained in another gas may be deposited on the gas-contacting
parts and ignite upon reacting with oxygen.
CAUTION
Prevent foreign matter from entering the device. If rust, water droplet, oil mist, or dust in the
pipes enters the device, measurement or control error or damage might occur.
If there is a possibility of foreign matter entering the device, provide a filter, strainer or mist
trap capable of eliminating foreign matter 0.1 µm or greater in diameter at the upstream. Be
sure to inspect and replace the filter at regular intervals.
Use the device within the operating differential pressure range. Also, do not subject it to
pressure beyond the rated pressure resistance range. Doing so might damage it.
Do not subject this device to pressure above its pressure resistance. Doing so might damage it.
Be sure to use within the flow-rate range stipulated in the product specifications.
To prevent excessive flow, use a suitable means to control the supply pressure or use a throttle
valve or the like to control the flow rate.
If the flow rate exceeds the upper limit, both the flow rate display and the output voltage/
current may indicate considerably lower values than the actual flow rate.
If damage could result from the abnormal functioning of this device, include appropriate
redundancy in the system design.
The valve on this device cannot completely shut a flow off. If complete shutoff is required,
provide a shutoff valve separately. When the external valve is closed, it is necessary also to
fully close the valve of the device using either of the following methods:
•
Set the flow rate setpoint to zero.
•
Make the valve operation mode to fully closed.
If this valve remains in normal control status when the external shutoff valve is closed (zero
flow rate), there will be an excessively large flow as soon as the external shutoff valve is
opened. For the MQV0050(J, K), MQV0200(J, K), and MQV0500(J, K), if the external shutoff
valve is closed continuously for 5 minutes or more in control mode or with the valve forced
fully open, the valve overheating limit (AL71) will be activated and the current to the valve will
be forcibly limited.