Robotic-style underwater vehicle enables the easy inspection of tanks and rigs.
What do you do when your storage tank springs a leak, you need to check a valve, or you simply want to see what may be clogging up the bottom of a dewatering basin?
Typically, the answer is to call out scuba divers or drain the whole tank. However, one alternative is slowly making the jump from the fish farm industry to the frac tank and offshore rig crowd — remotely operated underwater vehicles (ROVs). One easily handled option, manufactured by Deep Trekker, drew a crowd to the company’s demonstration tank on the floor of the 2016 Water & Wastewater Equipment, Treatment & Transport (WWETT) Show.
The Deep Trekker DTG2 ROV comprises two die-cast aluminum sides separated by a 360-degree polycarbonate window, through which the camera can look out. Double O-ring seals keep the water out, and the unit is completely self-contained.
“We are talking with tank manufacturers, municipal contractors who do tank work, and basically any individuals who perform tank inspection,” says Sean Phillips, engineering manager. “We originally marketed this product to the fish farm and pleasure boat construction industry but have gotten more and more inquiries from frac and water tank inspection folks, along with offshore rigs. That’s our biggest reason for coming to WWETT this year.”
The camera can rotate 270 degrees in the vertical plane and can be rotated to see both below and above the vehicle, and behind it to a limited degree. Panning the camera is accomplished by turning the ROV to the left or right using the thrusters mounted on each side. To see behind, the pilot can pitch the ROV body and look straight back.
“The controls are very similar to an Xbox video game controller,” says Phillips. “Not only does the ROV perform a needed service, the operators actually have fun doing it.”
Rechargeable batteries that power all the electronics, and the camera are all located inside the hull. The full unit weighs slightly less than 19 pounds and is rated to depths between 330 and 500 feet, depending on the model chosen. The unit’s depth is controlled using the two thrusters and an internal pitch control system. Adjustable ballast weights are located externally, allowing the unit to stay in a fixed submerged plane even in moving water.
Units are designed to capture or manipulate objects below the surface and come with 164 to 500 feet of tether cable, an integrated screen controller and cable reel. An optional two-function grabber arm can pick up all sorts of objects one might find at the bottom of a tank. It also allows operators to perform minor repairs or retrieve water samples. Heavier objects can be retrieved by locking the grabber onto them, and hauling the ROV and object back to the surface by the tether. Other options include a CHIRP sonar package that enables the ROV to be operated in low visibility, a thickness gauge, navigation sensors and auxiliary lighting to complement the standard lighting system.
Deep Trekker markets the DTG2 ROV as a versatile system. Besides municipal water treatment and fish farms, sales have been made to commercial divers, pipeline operators, underwater construction firms, search and rescue teams, and offshore rig operators.
“We have units in several West Coast municipalities, and NASA even bought one for tank testing and inspection,” says Phillips. “I would say the vast majority of our customers perform very niche duties involving underwater inspection or exploration. That’s why we felt it was a fit for this show.”The interest level was actually higher than expected for the first-time WWETT exhibitors, as the company sold five DTG2 ROV units right on the show floor. The interest in the ROV surprised Phillips, who came into the week thinking the company’s submersible crawler camera system would garner the majority of the interest.
“I would say the number of attendees who deal with tanks and tank inspections at this show was a surprise,” he says. “We did get a lot of great leads on the crawler system, but the interest in the ROV was just phenomenal. That leads me to believe that this show and this market is a great opportunity for Deep Trekker.” 519/342-3177; www.deeptrekker.com.