49. Lantana reptans Hayek Familia: Verbanaceae
5.2. Recomendaciones
Maintenance Check List Daily inspection
A daily inspection takes only a short time, but it will allow the operator to develop a definite sense of the appearance, sounds, and other operating conditions of a smoothly
performing compressor. Any changes can be investigated and be given attention before major problems develop.
Daily operator inspection checklist
Warning: exercise care when in the vicinity of hot surfaces, pressurized air, and high voltages.
Procedures accompanied by the alert symbol (!) Require special precautions as indicated.
() Operating data log
Operating parameters recorded and within specifications
Setpoints recorded
Gearcase(high surface temperatures) External surfaces wiped clean
No unusual noise or vibrations No oil leaks
No water leaks
No frayed or worn electrical cables
Intercoolers and aftercooler(pressurized air, high surface temperatures) External surfaces wiped clean
Condensate drains functioning properly No cooling water leaks
No air leaks
Lubrication system (high voltages at heater, pump motor) External surfaces wiped clean
Proper oil level in oil reservoir Proper oil color
No mist from ejector system No oil cooler water leaks No oil leaks
No frayed or worn electrical cables
Compressor drive motor (inspect visually only—high voltages, temperatures) External surfaces wiped clean
Properly ventilated
No erratic or noisy operation No frayed or worn electrical cables
Inspected in accordance with manufacturer‘s recommendations
Table 6.3.1 Example of Daily Operator Inspection Checklist
Scheduled maintenance
Table 1-2 below lists suggested intervals for prescribed scheduled maintenance
procedures such as those involving filters, lubrication, and other inspections and/or adjustments.
Bear in mind, however, that these intervals may vary with operating conditions and/or actual hours of machine operation. Some items may require attention more or less frequently as circumstances dictate.
Scheduled maintenance procedures () Weekly:
(or after about 150 hours of operation)
Inlet air filter elements inspected, replaced if required
Oil reservoir venting system filter elements inspected, replaced if required Bypass valve filter checked (if supplied)
Every six months:
(or after about 4000 hours of operation)
Oil reservoir venting system filter element changed Oil system filter element changed
Lubrication system oil tested and changed if required Coolant chemically tested
Bypass valve lubricated (if required – check instructions) Inlet guide vane assembly drive screw lubricated
Main drive coupling inspected and lubricated.
Drive motor ball bearings lubricated with recommended grease.
Oil pump motor lubricated with recommended grease Discharge air check valve inspected
Table 6.3.2 Example of Scheduled Maintenance Checklist Professional inspection
A substantial part of any good preventative maintenance program also involves professional inspection and replacement of common maintenance components after an established interval. Such in-depth inspection is particularly important when an unscheduled and/or long-term shutdown would seriously affect production. Table 1.3 below lists the items which require a professional service inspection whenever environmental or operational conditions dictate. Contact a authorized service representative for those procedures and for professional advice.
Service inspection checklist
To be performed with a manufacturer authorized representative:
() Gearcase
Impellers, inlets, and diffusers cleaned Impellers, inlets, and diffusers inspected Gearing visually checked
Gearing backlash clearances measured Axial pinion float checked
Clearances between impellers and inlets checked Intercoolers and aftercooler
Bundle tubes inspected, cleaned if required Bundle fins inspected, cleaned if required Cooler cavities cleaned and inspected Lubrication system
Piping connections checked for leaks Oil visually inspected
Oil cooler inspected Filters
All filter elements inspected Control panel
Inspected for proper operation Control valves
Inlet guide vane inspected Bypass valve inspected
Discharge air check valve inspected Drive motor
Main drive coupling inspected and re-greased
Motor inspected in accordance with manufacturer‘s instructions
Table 6.3.3 Example of Service Inspection Checklist by Professional
Compressors Failure Symptom
For compressor itself there are several common failure symptoms that must be pay attention in order to detect the problems, so that correction step can be done to prevent severe damage to occur. In the table below show the common symptom, cause and correction step for each symptom.
SYMPTOM CAUSE CORRECTION
High Discharge Temperature
Sump lubricant low. Fill lubricant.
Clogged or varnished heat exchanger/oil cooler.
Inspect lubricant lines for blocks.
Analyze lubricant.
If varnish is present, flush with cleaner.
Faulty thermal by-pass valve. Rebuild or replace by-pass valve.
Restriction of heat exchanger air
flow. Remove restrictions.
Insufficient air circulation at oil cooler.
Check location and make sure there is no restriction of cool fresh air.
Plugged oil filter element. Replace oil filter elements
Premature Lubricant Breakdown
Compressor operating too hot. See corrections for high discharge temperature.
Chemically active gases present. Review plant/operations/make-up air.
Analyze oil and correct inlet air source as needed.
Improper receiver condensate draining.
• Periodically drain receiver condensate.
• Inspect auto-drains, drain lines and valves.
Mixing incompatible lubricants. • Drain, replace and analyze oil.
• Flush compressor with cleaner.
Frequent Separator
Plug-Up / Collapse
Incompatible oil in compressor. Review and analyze oil.
Replace with proper lubricant.
Minimum pressure valve sticking. Rebuild or replace valve.
Ruptured intake air path filter. Inspect inlet filter and air path, checking for voids.
Replace and repair as needed.
Decreased Discharge Pressure
Excessive air demand. Check plant air demand and inspect plant for air leaks.
Service valve open. Close valve.
Leaky service line. Fix leaks.
Plugged inlet air filter. Clean or replace filter.
Inlet valve partially closed. Check inlet valve assembly and rebuild as needed.
Failure To Start
Safety shut-down tripped. Re-set compressor safety.
Disconnected main switch. Check switch and verify that power is ON.
Power failure. Check power supply.
High Power Consumption
Plugged air/oil separator Change separator element.
Wrong air pressure setting. Adjust setting.
Obstructed after cooler. Clean after cooler.
Plugged inlet air filter. Inspect and replace as needed.
Lubricant viscosity issues. Test and replace oil as needed.
Excessive Lubricant Consumption
Overfilled lubricant sump. Drain receiver to proper level Broken lubricant line .Replace lubricant line.
High compressor discharge temperature.
• Inspect and clean coolers.
• Inspect temperature control valve.
• Improperly positioned lubricant return scavenges line.
• Plugged scavenge line.
• Check scavenges line connections.
• Make sure that scavenge line is cut at 45° angle, reaches the bottom of the separator and isn‘t blocked.
Table 6.3.4 Common Failure System, Cause and Correction Step .
Preventive Maintenance Observation
Preventive maintenance is very important in order to maintain the compressor in their best condition. Listed below is the general preventive maintenance that can be done in order to maintain the compressor to work in their best condition.
1. Foundation
Annual. Examine concrete for cracks and spalling.
2. Frame
Annual. Examine metal for corrosion and cracks. Clean and paint if required.
3. Compressor Drive
Weekly. Check v-belts for slippage, chains for looseness, and shaft couplings for excessive run out or vibration. Dress or tighten v-belts if required. Tighten coupling bolts and lubricate coupling if required.
Annual. Check v-belts for signs of wear or aging and replace as needed. Check shaft run out of direct coupled machines with dial indicator and check shaft alignment if run out is excessive.
4. Cooling System
Weekly. Check flow of water or coolant through compressor and after cooler.
Check for accumulation of dirt and lint on cooling fins of air-cooled compressors and radiators or water-cooled compressors.
Annual. Check for corrosion and scale buildup and clean or flush as required.
Thoroughly clean cooling fins of air-cooled compressors and radiators of water-cooled compressors.
5. Air Intake
Weekly. Check condition of filter and intake for obstructions. Replace filter as required.
6. Piping and Valves
Annual. Check piping for corrosion. Clean and repaint or replace piping as required. Repack and reseat valves as required.
7. Aftercoolers
Not Scheduled. Check for leaks and for adequate water flow. Disassemble and check for internal corrosion and scale buildup. Clean as required.
8. Separators
Not Scheduled. Check for leaks. Disassemble and check for corrosion and scale buildup. Clean as required.
9. Traps
Weekly. Operate manual drains.
Annual. Check automatic traps for leaks and proper operation. Clean strainer and check for corrosion or scale buildup.
10. Dryers
Annual. Replace dryer elements as required on deliquescent dryers. Check operation of refrigerated and desiccant types.
11. Pressure Regulating Valves
Annual. Check operation and verify that regulating valves are providing correct pressure downstream from valve.
12. Pressure Relief Valves
Annual. Verify operation and setting. Check for signs of leaking, rust or corrosion, deposits, or mineral buildup. Perform operational test of relief valve either in service or remove and perform test on test stand. If a valve is found to be not functioning properly, the system immediately should be taken out of service until the valve can be repaired or a new valve can be installed. The relief valve setting should not be changed by plant personnel. The setting of a pressure relief valve can only be certified by an accredited repair facility.
13. Receiver Tanks and Other Pressure Vessels
Weekly. On air receiver tanks, open the receiver drain valve and blow down until water is removed from tank. Check for leaks on all pressure vessels. Annual. Make thorough inspection of exterior of the tank, paying close attention to joints, seams, and fittings. The inspection should be performed by a qualified inspector.
14. Gauges
Weekly. Check operation of gauge. Look for loose or stuck pointer. If there is any doubt about the accuracy of gauge, remove and check calibration or replace with new gauge. Biannual.
Remove gauge and calibrate. Make any necessary repairs or replace with new gauge if gauge is not repairable.
15. Pressure and Temperature Switches
Monthly. See that pressure switches cut in and out at proper pressures. Check setting of temperature switches. Annual. Check switch calibration and set points.
16. Unloader
Monthly. Check that compressor is not being loaded until operating speed is reached in starting and that it unloads at the proper pressure. Annual. Inspect valves and air lines for leaks and valves for proper seating. Lap valves if required. Examine solenoid for deteriorated insulation or loose connections.
17. Bearings
Weekly. Check antifriction bearing for excessive vibration or noise and schedule replacement as required. Check for adequate lubrication. Not Scheduled. Disassemble compressor and inspect condition of all bushings and babbitt-lined bearings. Repair or replace as required.
REFERENCE
1. R. Keith Mobley (2008). ―Maintenance Engineering Handbook 7th.Ed.”McGraw-Hill, USA. ISBN 978-0-07-154646-1
2. R. Keith Mobley (2004). “Maintenance Fundamentals.” Elsevier Butterworth-Heinemann, Oxford, U.K. ISBN 0-07-026005-2
3. Hanlon P.C., ed. (2001). ―Compressor Handbook” McGraw Hill, Two Penn Plaza, New York. ISBN 0-07-026005-2
4. Ling. A. L. and ViskaMulyandasari (2011) .“Compressor Selection and Sizing (Engineering Design Guidelines)” KLM Technology Group, Johor Bharu.
5. Roger Cline, John Germann and Bill McStraw(2009). ―Maintenance Scheduling for Mechanical Equipment” Facilities Instructions, Standards and Techniques, Volume 4-1A – Revised 2009, U.S. Department of the Interior, Bureau of Reclamation, Denver,
Colorado.
6. “Air Compressor Maintenance.” Industrial Power Air, Muskego, WI, USA.
7. Glenn K. Moore. (2009) ―Field Service Notes (Why Compressors Fail)”, Danfoss Ltd.
Denmark.
8. R. Keith Mobley (2008). ―Maintenance Engineering Handbook 7th.Ed.”McGraw-Hill, USA. ISBN 978-0-07-154646-1
9. R. Keith Mobley (2004). “Maintenance Fundamentals.” Elsevier Butterworth-Heinemann, Oxford, U.K. ISBN 0-07-026005-2
REFERENCES