Tube fitting eliminates underwater leaks

Without the remotely operated vehicles (ROVs) that lay desperately needed telecommunication lines on ocean floors, we might have even less bandwidth available to us than we have now. But some of these underwater creatures have hydraulic fluid running through their veins, so they are an environmental hazard. And with a typical ROV costing about $100,000 per day to operate, downtime from hydraulic leaks also becomes expensive very fast.

Unlike most pieces of equipment, leakage on an ROV can cause catastrophic failure, and potentially the loss of the equipment itself. ROV manufacturer Perry Slingsby Systems Inc. regarded leaks as a primary concern for their Triton^(R) T200, a state-of-the-art ROV built to work in the toughest conditions.

Perry Slingsby engineers chose Seal-Lok O-ring face-seal fittings, with exclusive Parflange technology from Parker Hannifin (Cleveland, Ohio), for the Triton application. The Seal-Lok fittings consist of a nut, fitting body, sleeves, and O-ring. The sleeves are attached to the tube by flanging with a Parker patented Parflange machine.

"I think what appeals to Perry more than the fitting itself is the way the tubing is flanged to create a single piece, smooth, flat surface for the o-ring to seal against," says Parker Hannifin's Jeff Mckelvey.

The Parflange has a 90 degrees sealing surface on the tube end. There is no braze joint, which removes a potential leak path. And when the Parflange fitting is assembled, it compresses the O-ring in a precision-machined groove that is designed to prevent fallout during assembly.

For more information about tube fittings from Parker Hannifin: Enter 542