Keep up the pressure
Even with all the technology we can throw at tires today, the most basic, yet the most important, is maintaining adequate inflation. “If a fleet has nothing else but a good air-pressure maintenance program, it will reap substantial benefits over having no program at all,” says Doug Jones, customer engineering support manager, Michelin Americas TruckTires.
It needn't be elaborate, but it has to be consistent, Jones says. Listed below are his top 5 steps to good tire inflation management.
1.The fleet tire-management program should be written, communicated, monitored and enforced. Appoint someone to check the tire pressures.
2. Establish target pressures and maintain them with calibrated air pressure gauges and trained employees willing to diligently check the pressures.
3. Conduct regular yard checks or tire pressure audits, document the results and take appropriate action.
4. Establish a routine for tire maintenance and inspections, including tire rotation, vehicle alignment and wheel and valve cap service.
5. Consider outsourcing tire management. If you don't have the time or resources to set up and run a maintenance program, there are many reliable outlets that can help.
By TMC's proposed definition, a tire would be considered under-inflated if its hot inflation pressure is less than 70% of the maximum inflation pressure stamped onto the sidewall of a tire.
How flat is flat?
We're all a little guilty of throwing the “F-word” around without a precise definition. You'll actually find several correct definitions, depending on who you ask.
The Rubber Industry Association considers a tire “run flat” if it has been run at less than 20% of the recommended inflation pressure. For a dual tire in a tandem axle group at full legal load, the recommended minimum inflation pressure would be between 75 and 80 psi. For a steer tire on a highway tractor, the minimum is about 105 psi under full legal load.
RI A's concern stems from possible damage to the sidewall caused by excessive flexing when underinflated, which can result in a nasty zipper rupture.
The enforcement community considers a tire to be flat if the pressure is less than 50% of the maximum cold pressure stamped on the sidewall (usually 120 psi).
In an effort to stem some of the confusion arising from all these standards, last fall theTechnology & Maintenance Council of the AmericanTrucking Associations adopted a reference it hopes the Commercial Vehicle Safety Alliance will adopt for enforcement purposes.
Briefly, by TMC's proposed definition, a tire would be considered under-inflated if its hot inflation pressure is less than 70% of the maximum inflation pressure stamped onto the sidewall of a tire. The tire would be considered flat if the pressure is less than 50% of the maximum indicated inflation pressure.
For truck operators, a flat tire is one whose inflation pressure is low enough to cause unreasonable delays and all sorts of grief and expense.