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Bfp de side bearing high temperature Route cause analysis
The document discusses the failure of the BFP DE side bearing, outlining its structure and function while focusing on high temperature issues. It includes a fishbone diagram identifying potential causes of high bearing temperature, such as improper lubrication, bearing clearance, and vibration issues. A 'why-why' analysis is conducted to further understand the root causes of these failures and suggests corrective actions to mitigate these issues.
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Bfp de side bearing high temperature Route cause analysis
- 1. BFP DE SideBearing Failure Aim towards zero failure-TPP P a g e | 1 Aim towards zero Failure Fishbone diagram and Why-Why analysis of BFP DE Side Bearing Temperature High
- 2. BFP DE SideBearing Failure Aim towards zero failure-TPP P a g e | 2 Contents BFP DE Side Bearing What is DE Side Bearing? Fishbone diagram of Bearing temperature high Why-Why analysis of Bearing temperature high
- 3. BFP DE SideBearing Failure Aim towards zero failure-TPP P a g e | 3 What is DE Side Bearing? DE side bearing is the bearing of the BFP which provide static support to the shaft space provided in between pump mechanical seal and coupling. In generally a static bearing (Split type Journal bearing) is provided as DE side bearing. Which means the bearing will not rotate with shaft, thus no rolling element is provided with in the split type bearing enclosure i.e. bearing housing. The Journal bearing partially dipped inside oil bath with in bearing housing and a oil splash ring is provided for splashing the oil from oil bath in between the bearing inner face and shaft. A layer of oil film is maintained in between the inner face and shaft. The oil film resist the metal to metal contact in between the shaft and inner face. Bearing inner face is coated with white metal or soft babit metal layer. The purpose of soft metal coating is to sacrifice for the protection of shaft in case of any oil film failure. The lubrication oil is cooled by external cooling water pumped by auxiliary water pump with in the jacket provided in side bearing housing. The oil level cup is provided on bearing housing body for visualizing the oil level. Also a drain plug is provided on housing bottom for draining lube oil during maintenance. 2nos Cooling water port inlet and outlet port is provided at both side of the housing.
- 4. BFP DE SideBearing Failure Aim towards zero failure-TPP P a g e | 4 Fishbone diagram of Bearing temperature high Machine Method Man Material Bearing housing damage Oil splash ring damage Babbitt layer damage Improper venting Base bolt looseness Coupling miss-alignment Shaft worn out Pipe line damage Improper lubrication Suction valve throttling Low pump RPM Low ACW pressure Low Deareator level Bearing life exhausted Impeller degradation Balancing disk erosion
- 5. BFP DE SideBearing Failure Aim towards zero failure-TPP P a g e | 5 Why-Why analysis of Bearing temperature high Sl. No. Reason Why 1 Why 2 Why 3 Why 4 Why 5 Root Cause Corrective Action 1 High Vibration Bearing rubbing with shaft Breakage of oil film Loss of oil viscosity Lube oil over heating Insufficient oil quantity Low Quantity of lube oil Rise lube oil level 2 Improper oil cooling Improper cooling Rise cooling water pressure 3 Lube oil contaminatio n Lube oil contamination Replace lube oil 4 High bearing clearance Bearing clearance high Replace bearing 5 High friction between bearing & shaft Abrasive scrubbing Lube oil contaminati on Mixing of Babbitt material to oil Breakage of Babbitt layer Bearing Babbitt layer damage Recoat Babbitt layer 6 Eccentric rotation of shaft Off centre between motor & pump centre line Axial or radial misalignm ent Mis-alignment Re Check pump alignment 7 Oscillation of pump body Improper vibration dumping Loose pump base Pump base bolt looseness Base bolt Looseness Tightened pump base bolt 8 Vibration transfer from pipe line Pipe line strain Pipe Vibration not dumped Improper pipe support Support not proper Install pipe support 9 Pump part rubbing with each other Looseness in parts Worn parts Parts Damage Replace damage parts 10 Excessive axial load on bearing Improper rotor axial thrust Balancing pressure is too high Clearance in balancing chamber Balancing disk worn- out Balancing disk damage Change balancing disk 11 Excessive radial load on bearing Shaft lifted too much high during operation Rotor high Radial thrust Pump radial lift disturbed Contact OEM 12 Resonance build up in impeller Un balanced mass of impeller Deposition of scale Scale deposition Clean impeller 13 Degradatio n of material Degradation of impeller Change impeller 14 Low lube oil cooling Heat transfer from oil not proper Low cooling water supply In sufficient flow quantity Low ACW pump pressure Low ACW pump pressure Rise ACW pressure 15 Low circulation pressure Flow restriction to coolant Chocking of cooling water pipe line Impurities in water Impurities in water Check for water impurity 16 Pressure drop at scale band Scale band chocking Scale band chocking Clean scale band 17 Improper lubricatio Restriction to lube oil Locking of oil splash Wear of splash ring Wear of splash ring Replace splash ring
- 6. BFP DE SideBearing Failure Aim towards zero failure-TPP P a g e | 6 n circulation ring 18 Change in lube oil circulating profile Defective bearing housing Damage Bearing housing Replace housing 19 Loss of oil viscosity Change in oil density Slurry formation Slurry formation in oil Replace lube oil 20 Heat transfer from shaft Heating of impeller Excessive heating of water Formation of cavitation Water vapour formation Pressure drop at pump suction Low suction head Rise Deareator level 21 Suction isolation valve throttled Full open suction valve 22 Clogged suction strainer Clean suction strainer 23 Low pump rotation Low pump rotation Rise pump speed as per Q-H curve 24 High back pressure Resistanc e to discharge Low discharge head Low discharge head Rise pump speed as per Q-H curve 25 Formation of air pocket Improper pipe venting Or pump priming Improper Air venting Release air from pumping system 26 High pipe friction Pipe rough internal surface Rough internal surface Replace pipe & pipe fittings