 |
| 15.03.2010 |
|
|
|
|
|
SIHI Liquid Ring Vacuum Pump Trouble Shooting FAQ
Bearing failure
| Cause |
1. Not using the recommended lubricant.
2. Over or under greased.
3. Couplings or V-belt drives not properly mounted or aligned.
4. Piping not properly supported and/or aligned.
5. Water in the bearings.
6. Internal pump clearances set improperly. |
| Effect |
| Seized pump and broken or damaged bearing housing. |
| Corrective Action |
1. Check the SIHI Pumps Asia manuals for recommended lubricant.
2. Check & clean bearings. (replace if worn)
3. Check alignment & foundations for proper support.
4. Use flexible connections for pump inlet, discharge and service liquid lines.
5. Check mechanical seals or packing. Shield bearings if environment is wet.
6. Consult SIHI Pumps Asia for assembly dimension or return for repair evaluation. |
80,00% of 5 voters found this FAQ useful, I found this FAQ  useful  not useful Cavitation damage
| Cause |
1. Liquid temperature too high.
2. Vacuum too high. |
| Effect |
| Holes or pitting at the tips and roots of the impeller blade and intermediate. Grinding noise when pump is running. |
| Corrective Action |
1. Lower the service liquid temperatures or increase the flow of service liquid.
2. Lower the vacuum level. (increase the pressure). |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful Corrosion
| Cause |
| Characteristics: Usually uneven, scaled on blackened surfaces and edges. Will occur on all wetted areas including impeller blade roots. Chemical attack of wetted pump parts (usually by acidic low pH). Sources may be vapors or liquids from the process or from the service liquid. |
| Effect |
| Accelerated damage of the impeller, intermediate plates, center body & end cover(s). |
| Corrective Action |
1. Monitor service liquid pH & treat as necessary.
2. Purge the service liquid loop on a regular basis.
3. Look for source of corrosives and treat or remove.
4. Change to a pump material e.g. stainless steel, which will not corrode. |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful Erosion
| Cause |
| Characteristics: smooth, clean, grooved surfaces and edges. Presence of sand, grit and other abrasive material. |
| Effect |
| Accelerated wear of impeller blades especially at the periphery. Premature wear of intermediate plate, center body & end cover(s). |
| Corrective Action |
1. Filter the service liquid.
2. Add pre-separators at the pump inlet.
3. Select proper pump materials. |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful Flooding the pump
| Cause |
1. Service liquid rate is too high.
2. Pump starts flooded.
3. Carryover from the process. |
| Effect |
| Impeller blades fatigue failure of shaft. Shaft deflection in single acting pumps possible, leading to mechanical seal leakage, high motor amperage. |
| Corrective Action |
1. Check the service liquid rate for the specific pump.
2. Piping may be installed incorrectly. Pump should drain to the centerline after shutdown.
3. Check for proper pump inlet separation. |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful Higher than normal pump noise
| Cause |
1. Pump is cavitating.
2. Pump is overloaded with liquid.
3. Pump has ingested foreign material.
4. Bearings are in poor condition.
5. Pump coupling or V-belt drive misalignment. |
| Effect |
| An unusual or high noise level is an early indication of a problem. This problem may lead to pump damage or failure. Potential vibration concerns. |
| Corrective Action |
1. Cavitation can be a complex problem. Consult with SIHI Pumps Asia for solutions.
2. Check for proper service liquid flow. Also check for good inlet pre-separation.
3. Stop the pump immediately. Disassemble and inspect or send the pump to SIHI Pumps Asia for repair evaluation.
4. Inspect bearings. See the subject of bearing failures.
5. Coupling and V-belt drive alignment must be checked. |
0% of 0 voters found this FAQ useful, I found this FAQ useful not useful Ingestion damage
| Cause |
| No inlet screens on the pump or compressor. |
| Effect |
| Broken impeller blades or seized pump. |
| Corrective Action |
| Return pump to SIHI Pumps Asia for repair evaluation. |
0% of 0 voters found this FAQ useful, I found this FAQ useful not useful Pump leaks
| Cause |
1. Leaking packing or mechanical seal. Note some leakage is necessary to keep the packing cool.
(Over tightening will harden, become hot & score the pump shaft.)
2. Leakage could be from the body, body gaskets or drain plugs.
(Sometime s a result of erosion or corrosion damage.) |
| Effect |
| Loss of service liquid. Potential gas leakage when shut down. In minor cases this may be a house keeping problem. In major cases this may lead to poor pump performance or damage to the pump. |
| Corrective Action |
1. Check packing and tighten or check & replace mechanical seal. Service liquid or contaminates from the process can coat or abrade mechanical seal faces.
2. Check the source of the leak. Repair may be necessary. |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful Pump runs warmer than normal
| Cause |
1. Insufficient service liquid flow.
2. Carryover of high temperature liquids.
3. Carryover of high temperature gases.
4. Pump RPM may be higher than recommended. |
| Effect |
| Capacity levels for the vacuum pump or compressor may decline. Also the vacuum level may fall. |
| Corrective Action |
1. Check the manuals or call SIHI Pumps Asia for the proper service liquid flow.
2. Check for proper pre-separation or call a SIHI technician.
3. High gas temperatures may be a process condition that may be unavoidable. Adjust service liquid flow as required. Call SIHI Pumps Asia if problem persists.
4. Check the pump RPM for the service. Call if necessary. |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful Scale
| Cause |
| Hard service liquids i.e. lime or mud. Pumps running hotter will accelerate this problem. |
| Effect |
A. Scaling will close the internal pump clearances & cause binding.
B. Scaling will cause a decrease in pump performance.
C. Scaling will slowly close the service liquid lines and cause the pump to run warmer. |
| Corrective Action |
| Use suitable descaler, but flush after use. Consult with SIHI Pumps Asia for recommendations on the type and quantities. |
0% of 0 voters found this FAQ useful, I found this FAQ useful not useful Vacuum level problems
| Cause |
1. Poor piping design. Vacuum or compressed air requirements and pumps may have been added without the required piping upgrades.
2. Warmer than recommended service liquid temperatures.
3. Incorrect service liquid flow.
4. Liquid carryover to the pump inlet.
5. Improper pump application.
6. Poor or insufficient vacuum control. |
| Effect |
| Vacuum levels that are usually lower than required. |
| Corrective Action |
1. See the section dedicated to piping design.
2. The addition of heat exchangers, cooling towers or chillers may be required. Consult with SIHI Pumps Asia.
3. Check the manuals or call SIHI Pumps Asia for proper service liquid flow.
4. Check for proper pre-separation.
5. Check application needs and call SIHI Pumps Asia for assistance.
6. Consult with SIHI Pumps Asia for sizing and selection of relief valves or revised vacuum control needs. |
0% of 0 voters found this FAQ useful, I found this FAQ useful not useful Vibration
| Cause |
1. Incorrect installation of foundation
2. Poor coupling or V-belt drive alignment
3. Slugs of water carry-over to the pump inlet.
4. Piping stress at the inlet discharge or service liquid connection s.
5. Pump ingested foreign material i.e. bolts, nuts, weld slag.
6. Internal damage due to cavitation, corrosion, etc. |
| Effect |
| Broken couplings, worn V-belt drives or broken foundation bolts. Pump bearings may fail prematurely. |
| Corrective Action |
1. Check with SIHI Pumps Asia on proper foundation and grouting procedures.
2. Check alignment or call SIHI Pumps Asia for assistance.
3. Check for proper pre-separation
4. Add flexible connections if necessary.
5. Pump should be sent to SIHI Pumps Asia for repair. Inlet screens should be installed before pump is started to insure material does not enter pump.
6. Repair or replace worn & damaged parts. |
100,00% of 1 voters found this FAQ useful, I found this FAQ useful not useful
|
|
|
|
|
Products & Services 
Condition monitoring of pumps