Tame Your Waterblasting Machine

Safety and efficiency are the result of smart operation and religious maintenance.
Tame Your Waterblasting Machine
A technician cleans the inside of a steel tank with a high-pressure waterblasting unit.

Like a hungry lion, waterblasting machines are big, bad and dangerous. Treat them right, though, and you can make them purr like a kitten. A lot of people don’t, according to Gary Toothe, training manager for Federal Signal Environmental Solutions Group.

“They don’t do the things that are necessary to keep it safe,” he says. “Those things also keep the machine efficient. Safety and efficiency are closely related.”

Proper maintenance starts with some simple daily checks that every operator should be doing before they hit the road. It doesn’t take long, less than five minutes, and it helps ensure the machine will operate safely. Following manufacturer recommendations will help you get the most out of your machine and keep workers safe.

Toothe recalls a training session in which he found all the belts on a machine were loose, so the customer tightened belts on all of its machines. “The next month, they told me they saved enough money to pay for my training and then some.”

As easy as it is, Toothe says checking belt tension is probably the routine maintenance item that is done the least. “You lose all the efficiency at the top end of the power curve, so you have to run your pump harder and longer just to get the kind of pressures you need.”

Keep it simple

Mechanics have specialized tools for tensioning, but there is a simple way to do a daily check. “Hit the belt with a wrench,” Toothe says. “It should bounce back and you should hear a ring rather than a thud.”

A quick check of the filter bag will ensure that it is not clogged. “Dirt is the No. 1 enemy of a waterblast pump,” Toothe says. “Bags cost less than $50 and pumps cost $75,000 and up. Pressurizing a piece of dirt up to 20,000 psi is going to do damage, and it’s the places you can’t see that you have to worry about.”

Lubrication lines are also easy to check to make sure they aren’t plugged. “Just make sure water is coming out of the lines so you know you’re getting proper lubrication of the plungers and packing sets.”

Rupture disks are important safety items that are often ignored or even disabled. They activate at 40 percent above the rated pressure in order to prevent over-pressurization that can cause equipment failures and injury. Some units have another disk that ruptures at 20 percent over rated pressure. Toothe prefers to use a pressure relief device rather than a second disk because it can be easily reset, rather than replaced, if it is activated.

There are a few things that should be done more than once a day. Most manufacturers recommend that bearings be greased every shift. The same is true with clutches unless they are self-lubricating. Toothe stresses that grease fittings should be cleaned before and after every greasing. “If they’re dirty, you’re actually pushing dirt into the bearings,” he says.

The power end oil reservoir needs to be checked every time the pump is started and about every 30 minutes. If the oil is discolored, it indicates water has gotten into the oil and it needs to be replaced right away to prevent equipment damage.

While most people don’t consider the bypass valve to be a safety device, Toothe believes it is and suggests it be checked monthly because it wears over time. If the valve is plumbed to send water back to the tank, the water picks up about 30 degrees of heat every time. Using it right ensures the equipment isn’t overheating and the water is the proper temperature so people don’t get scalded. Of course, every pump has a pressure gauge, but Toothe has seen many that have never been recalibrated.

When it comes to both safety and efficiency, Toothe says the most important thing to have is a qualified operator. “The difference is that a truck runner turns the pump on and off. If something goes wrong, he has to go get somebody. A qualified operator knows what to do when things start to go wrong.”


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