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

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© 2013 Axxiom Manufacturing, Inc.
3.4 Blast System Air Supply Line
The air supply hose and fittings must be rated at a minimum of 150 psi operating pressure. The
air supply hose from the air compressor to the blast unit should be at least the same diameter as
the air inlet piping (see Section 9.0). This size hose will be large enough to supply the required
airflow to operate the blast unit controls and each blast nozzle. See Sections 5.11 for further
information on air hose connection.
Note: If the abrasive blast system will be installed in a permanent location, the inlet connection
can be hard piped. Do Not install hard piping that is smaller than the piping size of the blast
system. Smaller piping size will reduce the air flow capacity. If other equipment will be using
the same source of air as the abrasive blaster, install a check valve at the air inlet. This will
protect against back flow of air pressure that can carry abrasive into the blast controls.
Hard piping connected to the abrasive blaster must be structurally supported so not to apply any
loading on the pressure vessel at the points of connection. Unsupported piping can create
bending loads at the connections on the pressure vessel and cause failure. Hard piping
connections to the pressure vessel must be designed and installed by qualified personnel
experienced with piping systems and the applicable codes pertaining to them.
External loading at piping connection can cause failure of the pressure vessel. Hard piping
connected to the pressure vessel must include supports to eliminate the possibility of applying a
load on the pressure vessel.
3.5 Blast System Air Pressure
The maximum allowable working pressure (MAWP) for the blast unit is stamped on the ASME
nameplate attached to the vessel. For most abrasive blast systems the MAWP is 150psig. Do
Not exceed the MAWP. An air pressure regulator can be installed to reduce air supply pressure
that is higher than the MAWP. To prevent air pressure backflow only use a non-relieving air
regulator. Air pressure backflow will carry abrasive from the blast vessel and contaminate the
blast control system. CRITICAL : Any inlet air valve or air pressure regulator added to the
system must have sufficient air flow capacity for proper operation of the blast system.
Insufficient air flow capacity will cause pressure drop in the blast system resulting in
equipment malfunction, abrasive backflow, and reduced blast productivity. Select a valve
that will operate with little or no pressure drop (5psi max.) at the required cfm air flow.
Installing an air pressure regulator allows the option of blasting at low pressure. When blasting
at low pressure the air supply to the deadman blast control system must be at least 80psig (see
Figure 5.4 and 5.5). The valves in the abrasive blast system are “spring closed” and therefore
require at least 80psig to operate properly. If the air pressure regulator is set below 80psig the
air supply to the blast controls must be taken upstream of the regulator.
3.6 Blast System Air Quality
Air quality is crucial to the operation of an abrasive blaster. Moisture and contaminants can
cause components to malfunction. Moisture condensation in a blast system causes abrasive flow
problems. Condensation occurs when the hot vapor-filled compressed air cools as it reaches the
abrasive blaster. Water droplets formed during condensation can be absorbed by the abrasive in
the blast vessel which can cause erratic flow to the abrasive valve. Therefore, a moisture
removal device installed for the blast system air supply is recommended (i.e. coalescing
moisture separator, air-cooled aftercooler or deliquescent dryer). Contact a local authorized
Schmidt® distributor or Axxiom Manufacturing, Inc. to locate one near you.
3.7 Electrical Requirements
On units equipped with electric blast controls the supply voltage is 12Vdc or 24Vac. The
maximum power required is:
1-outlet: 7 watts 1-outlet with abrasive cutoff: 14 watts
2-outlet: 14 watts 2-outlet with abrasive cutoff: 28 watts
Note: Insufficient electric power output will result in malfunctioning of the electric blast
control system. A power transformer or power supply can be used if the above voltages are not
readily available.