*Smooth connection between flange and pipes *The interior of the flange is welded in a circle and polished,NO welding slag. *Sensor position not protrude inside surface *Flange thickness we used are 10mm,12mm and 15mm *The deformation coefficient of the flange surface within 0.5mm *TIG weld make sure the firmness and gilding surface *Inside of pipe head polish 5cm,achieve better air flow and sound *Exhaust bellows use crochet net transverse,reducing vibrate frequency *Beautiful surface finish,polish or brush