AXXIOM Manufacturing, Inc. SCHMIDT, Руководство по эксплуатации и обслуживанию

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© 2013 Axxiom Manufacturing, Inc.
11.2.4. Blast is slow to turn on or will not turn on when deadman lever is pressed down.
(1) Check quick couplings (#16 & #17) on control hoses to see if they are connected properly.
(2) Control valve (#20) stuck in exhaust position or midway (air will leak from breather #21).
(3) 1/4" strainer (#23) blocked; restricts air flow to deadman.
(4) Twinline control hoses are blocked.
(5) Cartridge in deadman valve (#12) is blocked.
(6) Low air compressor output CFM (unit may cycle on and off). See Section 3.0.
(7) Air leaks in twinline hose from the deadman valve (#12) to control valve (#20).
(8) Trash blocking the blast nozzle orifice (#11).
(9) Blocked automatic air valve (#9) breather vent (#21) prevents full opening.
11.3 Notes on Abrasive Flow Problems
11.3.1. Thompson Valve® operation
If abrasive flow is a problem, remember; the Thompson Valve only opens and
closes. The total travel to full open is approximately 3/4 of an inch. This can be
quickly checked with the adjustment knob on the abrasive valve.
For this procedure manually close the choke valve (#13) and the media shut-off
valve to stop blast flow. This test is to verify that the Thompson Valve is opening.
With the deadman off, screw the Thompson Valve knob down until it stops. Notice
that the knob turns easily when the deadman is off. Next, back the knob out 3/4 of
an inch or slightly less, then press the deadman lever down to open the Thompson
Valve. The knob should get tight or more difficult to turn because the valve has
opened against the adjustment. This guarantees that the valve is fully open. If the
material will not flow with the valve fully open, you have an abrasive flow problem,
not a problem with the Thompson Valve. The abrasive may be wet, or there may be
trash blocking the opening. Try choking the blast outlet to clear the opening.
Proceed to step 11.3.2. If the knob does not get tighter during this test troubleshoot
the controls and the Thompson Valve piston seal.
Do Not hammer on any part of the pressure vessel to improve abrasive flow. This
can cause cracks that may lead to pressure vessel rupture.
11.3.2. Choking the blast outlet
The choke valve (#13) is used to clear any trash that may get into the blast vessel
and block the Thompson abrasive valve orifice. Whenever trash (paint chip,
cigarette butt, etc.) blocks the abrasive valve orifice, the procedure is to fully open
the valve by turning the knob counterclockwise, then press down the deadman lever
(#12) to begin blasting. While blasting, have an assistant close the choke valve
completely for about one second. This creates differential pressure at the abrasive
valve (high pressure above; low pressure below). The higher pressure from the blast
vessel should be enough to loosen the trash blocking the abrasive valve orifice and
blast it through the blast nozzle (#11). To minimize excess wear of the Thompson
Valve keep the choke valve fully open during normal blasting. If the blaster is
equipped with the abrasive cutoff feature set the valve (or switch) to the on-position
for the choke procedure (Thompson Valve blasters only).
Note: The Thompson Valve II has a cleanout port to use for this procedure. See the
valve drawings in Section 9.0 (Item 27).
11.3.3. Blast control hoses
Remember, the blaster controls and valves are normally closed. Therefore, the
control hoses are depressurized to turn the blast off and pressurized to turn the blast
on. If a needle gauge is available, it is the quickest way to check to see if there is
pressure or not. If no needle gauge is available, disconnect each control hose fitting
one at a time until the problem is located.