Start-Up; Shutdown - Ametek 270SF Instruction Manual

Start-Up

Apply power to the Model 270. Allow fifteen to twenty minutes for the filter to come to temperature. This warm-up period is
extremely important to avoid the condensation within the Model 270 filter which would cement the particulates to the filter
surface.
Start the sample pump and determine that the proper amount of sample is being supplied to the instrumentation.
Perform a calibration cycle to insure that the calibration lines are properly installed and sealed. A flow meter should be
installed in the calibration gas supply line to insure that there is at least 10 percent more calibration gas being supplied to
the Model 270 than is being withdrawn as sample. This will ensure that the filter and probe are being properly flooded with
calibration gas. The excess calibration gas will pass through the probe tube into the stack.
Open the instrument air valve to charge the blowback accumulator. Exercise the blowback solenoid valve to insure it is
properly wired. After a blowback cycle, the presence of a slight pulse on the sample tubing in the analyzer shelter and the
momentary dilution of the sample with instrument air is normal and signifies that a blowback cycle has occurred.
The optimum time between blowback cycles is to be determined by experience, once a day is sufficient in relatively clean
applications. The requirement could be as frequent as every fifteen minutes where the dust and soot levels are severe.
It is better to blowback too often than not often enough. A vacuum gauge in the sample line can be helpful to indicate if
the particulate loading of the filter has started to restrict the flow of sample. The blowback cycle should be initiated before
unacceptable pressure drop occurs.

Shutdown

Before removing power from the unit, ensure filter chamber has been purged of any potentially hazardous components.
To purge the chamber, perform the following:
1. If equipped, perform a manual blowback operation.
2. Close the filter stack isolation valve(s).
3. Ensure no sample is being drawn though the filter chamber. If the sample is being drawn using a sample pump,
turn off the power to the pump or disconnect the sample line.
4. If not already done, disconnect the sample line.
5. Use instrument air or other inert gas, flow ~10 l/m for 15-30 minutes through the filter chamber.
Note: Inert gas can be routed through the chamber via the calibration gas line.
6. After purging is complete, follow the maintenance procedure to change the filter.
7. Cap the sample outlet tube connection and disconnect power from the unit.
Note: If electrical wires are to be disconnected, follow applicable 'Lock Out/ Tag Out' requirements.
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MAN.270SF.REVA.12222014