In an effort to reduce the number of times a driver or technician has to go on top of a tank, the Cargo Tank Risk Management Committee (CTRMC) is calling for eliminating cleanout caps. A panel reviewed reasons for launching the campaign to eliminate clean-out caps during the National Tank Truck Carriers 2012 Tank Truck Show & Maintenance Seminar in Louisville, Kentucky.
“I understand this is a controversial subject,” said Dan Wright of Transport Service Co. “But how many times do you think a driver or technician climbs up and touches the cleanout caps? Every time he puts a trailer in a tank wash. It's not so much that we have drivers on top, but how many times do they go up and down? Sometimes four or five times a day.
“OSHA says any time you transgress from the ladder to the top of trailer, that's when you must have fall protection. As long as you're not on a ladder, you're OK. So we said, ‘Why do we have to continually go up? How many drivers fall off a ladder? Do we have the right hand grips, the right type of ladder? How many inches off the ground is the ladder?’ Drivers are not as fit as we'd like them to be. Sometimes they cannot quite get that leg onto the first rung. As far as eliminating cleanout caps, can we do it? I think so.”
The Cargo Tank Risk Management Committee (CTRMC) was formed in 2010 as a result of the Occupational Safety and Health Administration's (OSHA) concern about workers on the top of tanks.
Dave Girard, vice-president of Girard Equipment Inc, said tanks can be retrofitted with a hydraulically driven cleanout cap.
“On a typical DOT407 tank, one of the issues we have with cleanouts and their location is they have to be on the shadow line between two overturns,” he said. “We have limited space from a design standpoint to mount a valve without having to make it into a self-closing stop valve. We have a very limited height.
“That being said, we've come up with a low-profile design for a cleanout. This mounts on a traditional three-inch nozzle. With a low-profile unit, it opens up and shifts out of the way when it's fully open. It's hydraulically operated, opens up, and slides away.
“It's also threaded inside as an option to enable tank-cleaning equipment to fasten on that. This keeps drivers from having to access the tank by climbing on top. We are working on a final design, and we think we're onto something that will work well. We think it's a very worthy effort for CTRMC to address.
“I love the idea of CTRMC taking a multi-pronged approach: ladders, eliminating cleanouts, cleaning technology. There's no one fix to keep drivers off the top of tanks. There are certainly lots of options for cargo tank owners. We believe this is one of them. Asking a driver to get on top of a trailer in all types of weather and climb that catwalk is a recipe for disaster.”
Zeke Brown of Lechler USA said that in analyzing whether cleanouts can be eliminated, questions need to be asked and answered.
“From a cleaning perspective, what is the residue inside the tank?” he said. “How difficult is the material to clean? How often does cleaning occur? Are there baffles or other obstructions inside the tanker? Can cleaning occur from the center manway or somewhere other than the cleanouts?”
He said that a tank trailer with no baffles is a horizontal tank with a single entry point. The standard solution, he said, is an orbital machine.
“It systematically cleans every portion of the tank,” he said. “It's not just randomly spinning, it's systematically hitting every point.
“If your tank was a sphere, it'd be very easy to clean. The spray pattern would be of equal width and area. On a horizontal tank, the spray pattern is spread out in areas farther away. The spray pattern is most intense where tank walls are closest. This is generally true of all orbital tank-washing devices, regardless of pressure.
“Should you increase the pressure? Pressure doesn't alter the spray pattern or coverage. With pressure, less can be more effective because liquids traveling at high velocity break up quickly when impacting the air. High-pressure sprays lose effectiveness as you move farther away. Smaller droplets have little or no impact value for washing tanks. Repeated moderate impact is more effective in cleaning difficult soils.
“Spray patterns spread apart at greater distances. Spray patterns converge at the top and bottom of the tank-cleaning machine location. This is common with all upright orbital machines.”
He said the machine is placed in approximately the middle of the tank, one-third to one-half of the way down, with the nozzle butt plate aimed at the tanker heads.
“Baffles present another challenge,” he said. “Spray cannot reach the bulkhead via the center-mount only. When it comes to tank cleaning, it's all line of sight. Baffles create a physical obstruction to the nozzle spray and placement.
“On tankers with baffles, the typical solution is to insert a nozzle into each section. The nozzles are inserted in the end cleanouts. The standard opening is on the top of the tanker.
Brown said removal of cleanouts is possible from a cleaning perspective, but you have to look at what you're trying to clean.
“But assuming you can clean it with a nozzle, nozzles are safe, quick and use a lot less water,” he said. “If you are going to do this, you have to consider all possible obstructions. You can't just drop a nozzle and hope it's going to get clean. Let's attack this strategically and do it effectively.”