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		 Billy, I was working with a mechanical engineer a couple years back.  He told me it was easy but it didn't turn out that way.  I couldn't use PVC pipe with glued in fittings because of the air flow.  The Venturi had to have smooth transitions from large to small dimensions.  We were going to use a 3D printer to make the Venturi but it was to large for the printer we had access to. 
 
 I'm sure it can be done 
		
		
		
		
		
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