Impeller Overhaul; Inspection; Blade Leading Edge Repair Procedure - Hamilton Jet HJ212 Installation And Service Manual

Overhaul
Installation and Service Manual

Impeller Overhaul

Avoid using excessive heat during welding.
Refer to drawing: 82206 Impeller Dressing Information.
Impellers are stainless steel type CF8M conforming to ASTM A 743 or 316 to BS 3100.
Filler metal should have a chemical analysis similar to AISI 316L (carbon content less than 0.03%).
Post weld heat treatment is not required.
Passivation is required after welding.

Inspection

Check the impeller surfaces for corrosion.
Weld repair damaged areas and dress back to a smooth surface.
Check the impeller leading and trailing edges for damage.
Bent or dented blades may be straightened and dressed using suitable tools.
Bring the blade back to its original smooth profile checking against undamaged blades.
Check the leading edges.
Worn or blunt leading edges may be built up by welding.
Sharpen the leading edges as shown on the drawing.
Blunt impellers can cause loss of performance and cavitation.
Check the impeller O.D.

Blade leading edge repair procedure

Dress the edge back to a smooth curve, removing the minimum amount of metal.
Weld repair damaged edges.
Dress both faces of the blade. Take slightly more metal off the rear side until the leading edge is the correct
thickness.
Blend well back into the original blade surface.
Both front and rear surfaces are to be a smooth uniform curve with no sudden bumps or change in direction.
Grind or file a smooth radius along the leading edge.
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