RL HUDSON SUCCESS STORIES

AN ELEGANT SOLUTION TO A STUBBORN PROBLEM

By Changing the Materials and Adding Some Hardware, RL Hudson Designers Built a Hose That Withstands Heat, Vacuum and Oil Mist.

THE CHALLENGE

A customer that makes agricultural equipment approached us with a problem. They had a large air intake duct that was experiencing material degradation at high temperatures. In addition to high temperatures, the duct was exposed to oil mist and vacuum. There was also a brass fitting that was attached to the hose as a secondary operation.

THE SOLUTIONS

Our design team had a ready answer for the temperature and oil mist problems. They recommended making the duct out of wrapped silicone to resist heat with an inner liner of fluorosilicone to protect against the oil mist. The manufacturing process would also allow for the brass fitting to be incorporated into the duct at the factory. But a soft wrapped silicone product would not withstand the high vacuum generated by the customer’s agricultural vehicle.

To address this challenge, the design team used stainless steel rings installed in grooves on the outside of the duct. Putting the rings on the outside of the hose seemed counterintuitive at first. Wouldn’t the duct collapse under vacuum unless the rings were on the inside? The fact is that under vacuum, a round tube tries to change to an oval shape. The stiff round steel rings on the outside of the tube force it to maintain its round shape, thus resisting the effects of vacuum.

The newly designed duct met all the customer’s needs, eliminating failures while reducing the part’s cost. The design is now in use on a wide range of the customer’s products.