The equipment used in a retreading shop represents a sizable investment-greater even than that needed to establish an automobile dealership. Yet, despite this extensive outlay, many retreaders won't spend money to keep this equipment in first-class operating order.
Shortsighted? You bet! Any money saved by not carrying out proper preventive maintenance can't begin to cover the cost of the major breakdown that will inevitably occur when machines are operated without proper upkeep.
What's more, it's not possible to produce high-quality retreads using poorly maintained equipment.
A constant check should be kept on all parts subject to breakage and worn parts should be promptly repaired or replaced.
One of the basic principles is to post a maintenance schedule which also can serve as a good shopkeeping schedule.
Retreaders using steam curing equipment recognize it as the ``heart'' of their retreading operations. And the greatest amount of failures in the steam system usually can be traced to human error.
Problems often result from a failure to clean the boiler or maintain the water level and control devices.
One of the most important things a retreader can do to keep from turning out a sub-standard product is to keep such equipment in topnotch condition. This means constant inspections.
So before work gets under way some morning, slowly walk through your plant. Listen carefully. Those hissing sounds you hear represent dollars draining out of your pocket.
Leakage-whether in air or steam lines-is costly and completely unnecessary. The short time it takes to repair the leak will pay off immediately.
The two basic parts of the steam system are the boiler and the piping, which includes steam vents, regulators and traps.
One way of preventing steam system failures is through frequent inspection by a competent engineering firm. However, some parts of the system merit daily attention by shop personnel.
Dirty oil burner nozzles are a major cause of trouble in systems using such fuel. Improper fuel flow and faulty ignition will result.
The oil strainer, gas grates (if gas is the fuel), burners and boiler flues all should be cleaned monthly. The water line between the float control and boiler should get the same attention.
In the event of low water, the fuel supply must be shut off immediately. The feed water should not be turned on and the safety valve should remain closed.
Automatic control devices should be checked on a regular schedule. The low water feeder and the low water fuel supply cutoff should be tested on a daily basis. Sediment should be blown from the boiler and float control chamber daily.
The high frequency of failures resulting from operator negligence in testing and maintaining control devices is sometimes blamed on the widespread use of ``package-type'' boilers.
These excellent boilers, prevalent in the retreading industry, need little attention. But like any other mechanical device, they do need some care. The controls on these boilers also should be checked regularly.
The steam trap separates the low-pressure side of the system from the high-pressure side. A steam trap should open when it senses water and close when it senses steam. A partially open steam trap sends steam back to the condensate tank, nibbling away at your profits.
Leaking traps can be determined by observing the condensation tank vent. If conditions are normal, there will be occasional puffs of steam released along with the condensate when traps open. If a steady stream of steam is observed, there are some open traps.
If a steam trap is not removing water as it should, the condensate in the pipes will cause excessive ``water hammer.'' This banging is not just sound. Water being forced along a pipe at high speed may hit an elbow and burst the pipe.
Longer curing times or uneven cures are other signs of trouble in the steam trap. If pressures and temperatures are giving fluctuating and inconsistent readings, then the steam traps might not be removing water as they should.
Use a surface pyrometer to check inlet and outlet temperatures. Temperatures should be below 212 degrees Fahrenheit on the outlet side and close to operating temperature on the inlet side.
Clean off sediment, which sometimes collects on the steam trap parts despite the use of strainers.
Worn parts should be replaced. But some retreaders spend money unnecessarily replacing usable parts for regulators and traps.
Some years ago, I dismantled a regulator that was scheduled for replacement. It was full of dirt and sludge. After washing the parts with rubber solvent and reassembling the regulator, it worked perfectly.
Steam feed pipes must be insulated and kept out of drafts. A winter breeze can cause a ``lock'' in the pipe that will block the passage of steam.
Like the human heart, the ``heart'' of the retread shop should be treated with care. A little attention pays off in better health.