Guyson Euroblast PF, Operating & Maintenance Instructions

Page: 22 / 84

Operation &
Maintenance
Manual
Issue: 09 A6ML0165 - Euroblast PF Manual
Date: 05/2019 Page: 22
5.1.2 Media control valve
This operation will be greatly eased by the assistance of a second operative.
Note: The greater the flow of media from the media flow control valve to the blast nozzle, the
higher the rate of wear of all wear parts especially media hose, blast nozzle and exhaust wear
plates.
The media flow from the base of the pressure pot to the nozzle is controlled by the hand wheel on the
bottom of the pot. This operates a valve between the pressure pot outlet and the Y branch in the main
air pipe. This media flow control (or grit) valve should be gradually opened while the foot pedal is
depressed until a steady stream of media is coming from the nozzle.
Do not open the media valve more than is necessary for a steady flow of media from the nozzle:
excessive media in the media hose will cause erratic and intermittent flow of media to the nozzle.
In certain circumstances, for instance with lightweight media, it can be difficult to achieve the desired
media flow at any position of the media valve from fully open to fully closed. This is because the
media in the pressure pot is not liquidised preventing media from flowing through the media control
valve. An adjustment of the airflow is therefore necessary.
The nozzle ball valve controls the air flow balance. By default the ball valve should be fully open. To
make more air flow through the pressure pot, to liquidise the media, close the ball valve slightly. This
resetting of the ball valve upstream of the media valve means that less air is flowing down the main
air hose and more air is flowing into the pressure pot which in turn liquidises the media causing the
media to flow (see figure 1).
Once media flow is achieved by the gradual closing of the nozzle ball valve then the media valve
should be adjusted to even out the flow. Small adjustments of both valves may thus be needed to
achieve optimum performance.
Nozzle ball valve Media flow control valve