Not Enough Abrasive in the Blast Stream

Follow along to learn the possible causes and fixes for not gettting enough abrsive through your blast system.

Possible Causes for Not Enough Abrasive

1. Low levels of abrasive are in the pot.

2. There is blockage in the pot or within the abrasive hose. 

3. The abrasive ball valve is closed. 

A. Make sure that the abrasive ball valve is open.

4. The selector is in the wrong position.

A. Make sure selector is in the BLAST position.

5. The abrasive metering valve is closed.

A. Confirm that the abrasive metering valve is open half-way. Then, fine-tune it after you get the abrasive flowing.

6. The initial pot pressure is set too low. 

A. Close the abrasive ball valve and put the selector in the FILL position and confirm pot pressure is 30 psi (2 bar) above the blast pressure setting.  Adjust if necessary.

B. Note: gauge must be functioning normally to confirm pressure.

7. The selector valve's handle is loose on its shaft.

A. Check the selector valve set screw to confirm it is aligned on the shaft and is set tightly.

Restarting the Blast Stream

 To begin, first confirm that there is abrasive in the pot and that it is free-flowing.

1. Close the abrasive ball valve.

2. Operate the unit in WASH until only water and air are blasting.

3. Depressurize the pot, and then open the abrasive ball valve to relieve pressure in blast circuit plumbing.

4. Close the abrasive ball valve and slowly disconnect quick coupler.

5. Put selector into FILL and after pot pressure builds to initial pot pressure setting, slowly open abrasive ball valve with hose held over an empty bucket.

6. Confirm that there is a steady flow of media from the disconnected hose.

A.If only water flows, reload pressure-pot with abrasive per instruction manual.

B. If no abrasive flows, there could be blockage in abrasive hose or in the bottom of the pressure pot.  Correct as necessary.

7. Put selector into WASH and clear media from blast circuit plumbing.

8. Remove the grommet in the female portion of the quick coupler.

9. Stand clear of quick coupler and briefly engage the blast control switch (3 times) to back-flush the diaphragm valve.

10. Clean female and male portion of quick coupler and reinstall the grommet.       

11. Put selector in RINSE and re-connect quick coupler.

12. Remove nozzle and inspect cone for foreign matter.

13. Put selector in WASH.

14. With nozzle off, blast for a few minutes to clear blast hose of debris.

15. Re-install nozzle (do not over-tighten).

16. Pressurize the pot, open the abrasive ball valve, put selector in BLAST, set the abrasive metering valve half-way open, and see if abrasive is now in blast stream.  Be patient as it may take a few minutes to recharge the hose.

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