A strong hose recoil occurs frequently when the blast control switch is engaged.

  • Place the unit on a level surface.
  • If this is not possible, the Auto-Vent must be on the higher side of the unit.
  • Confirm the Auto-Vent valve is working and set initial pot pressure 30 psi (2 Bar, 0.2 MPa) above the blast pressure.
  • Perform Auto-Vent cleaning procedure.
    • Try to push and quickly release the valve with your finger.  If that does not cause the valve to seal, open the dump valve to release all of the pressure in the pot.
    • Open the dump valve to relieve pot pressure.  Open the pop-up and drain the pot until the water level is below the pop-up.
    • Turn the selector valve to RINSE.
    • Use the rinse hose to force water backwards into the valve stem.
  • If the previous steps fail to resolve the issue, replace the whole valve assembly.
  • Perform the diaphragm flush procedure.
    • Operate the unit in WASH until all abrasive clears from the blast hose.
    • Close the abrasive ball valve, then turn the selector valve to RINSE.  Blast until the hose is clear of all abrasive and water.
    • Disconnect the quick coupling at the abrasive ball valve (not at the bottom of the pot). 
    • Turn the selector valve to WASH.  Remain in WASH until all debris is clear.  Remove the grommet in the quick coupler.
    • Make sure nothing is in the path of the open quick coupler, then engage the blast control switch briefly and several times.
      • High flow air should escape though the cam-lock coupling.  If this does not occur, the diaphragm valve is malfunctioning.  Replace entire diaphragm canister.
      • DO NOT disassemble the canister.
    • Hold the male end of the quick coupler up to the water coming from the cam-lock end of the coupler.  Clean off any dirt or abrasive.
    • Turn the selector valve to RINSE to stop the flow of water.
    • Re-insert the grommet into its interal grooce instide the cam-lock.
    • Reconnect the quick coupler.  If properly cleaned and connected, there should be no leaks at the coupler during operation.
  • If flushing does not solve the problem repair the diaphragm valve.
    • Perform the pressure relief procedure in the manual.
    • Apply more than 80 psi (5.5 Bar, 0.55 MPa) air pressure to the regulator inlet to cause the piston to retract.
    • Loosen all 4 Allen-head cap-bolts evenly and then remove them completely while supporting the canister of the diaphragm valve.
      • DO NOT disassemble the canister.
    • Replace the diaphragm (natural rubber compound) and hand-tighten it (only as far as necessary) to establish the alignment of the canister.
      • There are one or two shims between the diaphragm and the actuator.  Keep the shims and reuse them (they do not come with the replacement diaphragm).  Do not cause any pre-load or torque on the diaphragm by over-tightening it in a misaligned position.
    • Insert all 4 Allen-head cap-bolts and hand-tighten.
    • Tighten the cap-bolts in an alternating pattern (Top Left, Bottom Right, Top Right, Bottom Left) to 80 in/lbs (9 N*m).  This will cause a slight bulge in the diaphragm between the canister and the stainless steel casting.
    • Relieve the pressure applied in step 2.
    • Test and confirm that the unit is working properly.
      • This can be done using only water to charge the equipment, there is no need to use abrasive for this test.