... spray and wetly spray the concrete, HPZ-5 concrete sprayer is the newest product with the highest technology in the ... slow material dropping, little left material, little dust, tight point-pressure, easy adjustment, convenient maintaining, and about the rubber sealing board ... ) Inside-diameter of material-conveying tube: 50 10) Operation wind-pressure: 0.2 - 0.4MPa 11) Operation wind-intensity: 7 ...