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P a g e
3.3 Technical Notes & Best Practices
Technical Notes
•
The device sets an “at least pressure”:
This device sets a minimum level of pressure for the main
stream, therefore, if more devices are placed in series, the main stream pressure will be equal to
the highest device set point of (and not the sum of their set points).
•
Robustness to clogging:
While this device is not designed for slurries, users observe an increased
robustness to clogging when particles/solids are present with respect to conventional devices. The
reason has l to do with the redundancy of internal passages present inside the device.
•
Error:
These devices are very accurate and precise, providing small errors (~<1%). For reference, a
standard spring-based device has a typical error of 10%. The device can be run outside the
suggested range of flow rates, but the error will increase.
•
Use with hot liquids:
If the device is used in the “
Set It and Forget it Mode”
, it will heat up when
used with hot liquids. As a result, the pressure set point may change because the reference gas will
heat up.
•
Dynamic Set Point:
“When using the dynamic set point, the precision of the device depends on the
precision and stability of the compressed gas source. If pressure of the gas fluctuates, so will the
set point of the device.”
Best Practices
•
To prevent damage to the valve,
do not over tighten the valve,
finger tight with a small flat head
screwdriver is sufficient for tightening.
•
The same carefulness needs to be taken with the connector for the “charging” or set point gas (if
using the port with the valve). Finger tight will allow the user to charge the device to their desired
setpoint without the need to overtighten the fitting with a wrench. If using a wrench, only
provide the slightest amount of torque.
•
To prevent damage to the connector used to pressurize the device, do not torque the connection
tube when it is connected to the BPR. This can cause the fitting to break off in the valve. The seal
between the valve and the connector is achieved via an O-ring and tightening hard will only
damage the connector. As a result, connection tubing and BPR should only be moved gently
when connected.
4 Maintenance
4.1 Cleaning the Device After Use
The wetted parts of the BPR-1000 are all made with inert polymers, therefore minimal care is
required. However, rinsing with a solvent/water stream after use is suggested. The rinse is
especially recommended if liquids carrying salts are used. The liquids use to flush the device should
be selected as not to react with the process fluids. The rinse should be focused on dissolving any
potential precipitates inside the BPR.
