... Used to during spray, moistly spray and wetly spray the concrete, HPZ-5 concrete sprayer is the newest product with the ... little dust, tight point-pressure, easy adjustment, convenient maintaining, and about the rubber sealing board, long life, little volume, great ... projects such as tunnels, culverts, railways, roads, subways, water and electricity, mine-shafts 4) Production ability: 5 - 5.5m³/ ...