WATER SPRAY SYSTEM
1. General. The water spray system is used to wet the front and rear drums to help prevent hot asphalt from
sticking to the drum surfaces during compaction. The water spray system consists of two identical, but
separate systems, one at each end of the roller. The water spray system uses pumps that provide
pressurized water flow. Only one pump operates at a time. The pumps are controlled by a switch on the
operator console. This switch has three positions: off, continuous spray, and intermittent spray. The
continuous spray setting turns on the water spray system and water sprays on the drums continuously. The
intermittent spray switch position uses fifteen-second on/off cycles of water spraying on the drums to reduce
water consumption. There are three draincocks that allow the water to be drained from the system. The
pumps pull water from two tanks and water spray screens which filter foreign material from the water. The
water then enters the pump and is pumped to the spray bar. There are seven spray nozzles in each spray
bar which distribute the water evenly over the surface of the drums. A check valve is located at the end of
the spray bar to control the pressure of the water in the spray bars. Excess water is sent past the check
valve and back into the water tank. On the CB534B Roller only, the front and rear water spray systems are
connected by a tie-line valve, which allows one water spray system to supply pressurized water to the
nozzles of the other water system, in the event of failure of one the pumps.
2. Water Spray Pumps. The water spray pumps are electrically activated positive displacement piston-type
pumps that operate on 24 VDC. When activated, the pumps provide pressurized water flow to the water
3. Water Spray Screens. The water spray screens filter foreign matter from the water supply. There are two
screens at the water tank fill port and two in the water spray system.
4. Water Spray Tanks. The water spray tanks store water to be used in the water spray system. There is a
screen on top of the tank at the fill cap that acts as an initial filtering device at the tank.
5. Check Valves. A check valve is installed in each water tank at the end of each spray bar. The check valve
regulates the water pressure in the spray bar and allows excess water to flow back into the water tank.
6. Water Spray Bars. The spray bars distribute water to the spray nozzles. There are seven outlets on each
spray bar where the spray nozzles are attached. The spray bar is adjustable to change the coverage of
water to the drums.
7. Water Spray Nozzles. The water spray nozzles spray water in a fan pattern onto the drums. The nozzles
are made of polyethylene and brass and contain a wire mesh screen to filter foreign material. There are 14
nozzles and all are adjustable.
8. Draincocks. The draincocks are directional valves that allow the water spray system to be drained. There
are three draincocks on the roller. One is located near each of the two water pumps and a third is located
near the tie-line valve.
9. Tie-Line Valve. On the CB534B Roller, the tie-line valve is located in the center of the roller. The on/off
valve allows the front and rear water spray systems to interact. When this valve is open, one pump can send
water to both the front and rear spray bar and nozzles.
10. Drain Nipples. The drain nipples are located on the bottom of each water tank. Each tank can be completely
drained by removing the cap assembly from the nipple.
11. Shut Off Valves. On the CB534B Roller, shut off valves interrupt the flow of water from the water spray tank
to the water spray screen and spray pump. When turned off, water from the water tank cannot reach the
rest of the system.