Ask:
“What are the keys to maintaining an efficient compressed air system?”
Answer:
Key #1: PREVENTIVE MAINTENANCE
“What is the key to maintaining an efficient compressed air system?” The best answer would have to be: preventive maintenance.
WHAT IS PREVENTIVE MAINTENANCE?
According “Wikipedia”: Preventive Maintenance (PM) has the following meanings:
“The care and service by staff in order to keep equipment and facilities in good working order.
satisfactory operating condition by providing systematic inspection, detection, and correction of incipient failures, either before they occur or before they develop into major defects.
Maintenance, including tests, measurements, adjustments, and replacement of parts, performed specifically to prevent failures from occurring.”
*Source: From Federal Standard 1037C and MIL-STD-188 and Department of Defense Dictionary of Military and Associated Terms
Preventive maintenance activities include partial or complete revisions in specific periods, oil changes, lubrication, etc. Additionally, workers can record equipment wear and information so they know how to replace or repair worn parts before they cause system failure.
The ideal preventative maintenance program would prevent all equipment failures before they occur.
BENEFITS OF PREVENTIVE MAINTENANCE:
-Improves system reliability and helps keep equipment running and/or extend equipment life.
-Decreases system downtime and actively helps prevent unbudgeted maintenance costs from arising.
-Decreases the cost of having to replace equipment so often.
-Records operational data that can help you troubleshoot an emerging problem (called “Data Trends”)
Data trending is the recording of basic operating parameters, including pressures, temperatures, and electrical data. For example, a slow rise in temperature indicates a variety of maintenance requirements, including cooler core cleaning, system overload, and potential mechanical issues. Another example might include a slow decrease in pressure, indicating increased system flow requirements, reduced compressor performance, or increased system leaks. Make sure someone is looking at this data regularly. If the data is never reviewed, the benefit is lost.
THE VALUE OF PREVENTIVE MAINTENANCE:
To determine how valuable regular air compressor PM is to you and your business… you need to know what your “downtime” is worth. In some operations, downtime can cost hundreds, even thousands of dollars per hour.
There are many misconceptions about preventative maintenance…one of them is that it costs too much.
This line of thinking says that regularly scheduled downtime for maintenance costs more than operating the equipment until repair is absolutely necessary…or until the equipment breaks. This may be true for some components, but don’t forget to consider the long-term benefits and savings associated with preventative maintenance noted above.
If regular preventative maintenance can help reduce unexpected downtime that results in lost production, time and materials, or the ruin of a costly plant process, then it’s worth the investment. Not to mention, unscheduled shutdowns can be extended if the correct equipment parts or repair technicians are not available.
“How effective is your PM program?”
The answer is: “If your PM program finds no problems, it is not effective.”
Key #2: CORRECTIVE MAINTENANCE
Corrective maintenance, often called “repair,” is performed to get equipment back in working order.
or fix any problem found during Preventive Maintenance.
The main objective of maintenance is to avoid or reduce the consequences of the failure of your compressed air equipment. PM is designed to preserve and restore equipment reliability by replacing worn components before they actually fail.
Key #3: EVALUATION OF YOUR TEAM: When to maintain and when to replace.
Here are several factors to consider when evaluating your compressed air equipment:
-How critical is your compressed air equipment? If the equipment fails, what is the impact on production or safety?
-What is the age and history of your team.
Equipment histories will show that most failures occur during infancy (newly installed or recently refurbished) and old age (self explanatory).
How many times has this team failed in the past?
– How confident are you that this equipment will work as designed when it is scheduled to work?
-Do you need newer technology in your equipment?
Evaluating the answers to these questions will help you determine when your old equipment needs to be repaired or replaced. Preventative maintenance will help your equipment last longer, perform better, and save you a lot of money in the long run.
Key #4: KNOW YOUR TEAM WHAT IT NEEDS:
-All compressed air equipment should come with a set of MAINTENANCE INSTRUCTIONS and some type of operations and parts manual. Your operators should review the equipment information and keep it handy for future reference. If you purchased used equipment and don’t have the manuals, contact your equipment dealer for a copy.
– Follow the maintenance guidelines for your equipment.
BASIC PREVENTIVE MAINTENANCE CHECKLIST FOR
RECIPROCATING AIR COMPRESSORS (PISTON):
Before performing any maintenance functions, switch the main disconnect switch to the “off” position to ensure no power is going to the unit. “Lock out” or “Tag out” all energy sources. Be sure to relieve all air pressure in the unit. Failure to do this may result in injury or equipment damage..
DAILY MAINTENANCE
1. Check compressor and engine oil level, if equipped. Add quality air compressor lubricant as needed.
2. Drain moisture from the tank by opening the tank drain valve located at the bottom of the tank. Do not open drain valve if tank pressure exceeds 25 PSIG.
3. Stop, look and listen for any unusual noise, compression failure, overheating, vibration or belt slippage and correct before damage of a serious nature develops.
4. Shut down the compressor at the end of each day’s operation. Turn off the power supply.
WEEKLY MAINTENANCE
1. Clean dust and foreign matter from cylinder head, engine, fan blades, air lines, intercooler, and tank.
2. Remove and clean intake air filters.
CAVEAT
Do not exceed 15 PSIG nozzle pressure when cleaning element parts with compressed air. Do not direct compressed air against human skin. Serious injury could occur. Never wash items in fuel oil, gasoline, or flammable solvent.
3. Check that V-belts are tight. The V-belts must be tight enough to transmit the necessary power to the compressor. Adjust V-belts as follows:
has. Remove bolts and shield to access compressor drive.
b. Loosen the mounting hardware that holds the motor to the base. Slide the motor into the slots on the base plate to the desired position.
Contra Check manufacturer’s specifications for correct belt tension. Apply pressure with the belt tension tester to one belt at the midpoint of the span. Make further adjustments if necessary.
d. Check pulley alignment. Adjust if necessary.
me. Tighten mounting hardware to secure motor to base.
F. Reinstall guard and secure with bolts.
CAVEAT: Never operate unit without belt guard in place. Removal will expose rotating parts that can cause injury or equipment damage.
EVERY 90 DAYS OR 500 HOURS MAINTENANCE
1. Change crankcase oil. Use the type and grade of oil as specified.
2. Check for air leaks throughout the system around fittings, connections, and joints, using an ultrasonic leak detector or a soapy solution and brush.
3. Tighten nuts and cap screws as needed.
4. Check and clean compressor valves, replace packing valve assembly when worn or damaged.
BAIL: The valves must be reinstalled in their original position. Valve gaskets should be replaced each time valves are serviced.
5. Pull the ring on all pressure relief valves to ensure proper operation.
GENERAL MAINTENANCE NOTES:
PRESSURE RELIEF VALVE: The pressure relief valve is an automatic pop valve. Each valve is properly adjusted for the maximum pressure allowed by the tank specifications and the working pressure of the unit in which it is installed. If it explodes, it will be necessary to drain all the air from the tank to put it back in properly. Do not reset.
RESERVOIR DRAIN VALVE: The drain valve is located at the bottom of the tank. Open the drain valve daily to drain condensation.
Do not open drain valve if tank pressure exceeds 25 PSIG. Compressor equipped with automatic tank drain requires manual drain once a week.
PRESSURE SWITCH: The pressure switch is automatic and will start the compressor at low pressure and stop when the maximum pressure is reached. It is adjusted to start and stop the compressor at the proper pressure for the unit it is installed on. Do not reset.
BELTS: Drive belts must be kept tight enough to prevent slipping. If the belts slip or squeak, refer to V-Belt Maintenance in the previous section.
BAIL: If the belts are too tight, the motor and motor bearings will be overloaded.
COMPRESSOR VALVES: If the compressor does not pump air or seems slow to fill the tank, disconnect unit from power source, drain air tank, remove valves and clean thoroughly with compressed air and a soft wire brush. After cleaning, special care must be taken that all parts are put back in exactly the same position and all joints must be tight or the compressor will not work properly. When all valves are replaced, perform a timed pump down test and verify that it meets factory specifications. The valve seals must be replaced each time the valves are removed from the pump.
Bottom line: One of the main keys to maintaining an efficient compressed air system has been and continues to be “Preventive Maintenance”.