Bearing Maintenance and Lubrication

Best Way to Clean a Bearing

• The best practice is to first remove the bearing from the machine before cleaning.

Heating Bearings for Installation

• Using a propane torch is not an acceptable method for heating bearings.
• Acceptable heating methods include oil baths, induction heaters, and specialized hotplates.

Disadvantages of Sodium-Based Greases

• Sodium-based greases are unsuitable for use in wet locations.

Collar Thrust Bearings

• Collar thrust bearings can prevent a rotating shaft from moving in axial directions.

Air Compressor Oil Requirements

• Air compressor oil should have low carbon residue.

Oil Grooves in Shell Bearings

• Oil grooves disrupt the oil film and cause potential damage when placed in the pressure zone of a shell bearing.

Causes of Bearing Failure

• High oil temperature is a potential cause of bearing failure.

Oil-Related Bearing Failure

• Improper oil selection can lead to oil-related bearing failure, in addition to excessive oil temperature and loss of oil.

Lubrication During Startup/Shutdown

• Boundary lubrication occurs during the starting or stopping portion of machinery operation.

Oil's Ability to Support a Load

• Viscosity is the property of an oil that indicates its ability to support a load.

How Oil Reduces Heat in a Bearing

• Oil reduces heat in a bearing by reducing friction.

Oil Exposure to Air

• Oil will oxidize when exposed to air.

Mineral Oil Composition

• Mineral oils are made from petroleum.

Lubricant for Slow-Moving Shafts

• Grease is recommended for boundary lubrication in slow-moving shafts.

Babbitt as a Shell Bearing Material

• Babbitt is a suitable metal for shell bearings because it will deform slightly.

Function of Bearing Seals

• Bearing seals keep foreign material out and the lubricant in.

Kingsbury and Michell Bearings

• Kingsbury and Michell bearings are tilting pad thrust bearings.

Liquid Lubricants Not Used Alone

• Fixed oils (e.g., lard, castor oil, canola oil) are liquid lubricants not often used on their own.

Lubricant for High Temperatures

• Synthetic oils are suitable for high temperatures and sludge/oxidation resistance.

Indicating Oil Acidity

• Neutralization number indicates the acidity of an oil.

Separation of Surfaces by Liquid

• Lubrication is the separation of two surfaces by an interposing liquid.

Lubricant for Difficult-to-Reach Machinery

• Solid lubricant is useful for machinery difficult to reach and service.

Function of Oil in Steam Turbine Systems

• Pour point suppression is NOT a function of the oil in a steam turbine oil system.
• Functions include governor control system fluid, heat removal and friction reduction.

When to Use Grease

• Use of grease is warranted when the lubricant must stay in place.

Oil's Fire Point

• Fire point is the temperature at which oil produces enough vapor to ignite and burn continuously.

Wearing Rings

• Wearing rings are used on impellers and casings, help reduce pump maintenance costs.

Total Static Head of a Pump

• The total static head is the difference between static suction head and the static discharge head.

Component Preventing Leakage in Mechanical Seal

• An O-ring gasket prevents leakage between the pump shaft and the mating ring in a mechanical seal.

Volute Type Pump

• A volute type pump has a progressively expanding spiral casing.

Purpose of Safety Head on Refrigeration Compressor

• A safety head on a refrigeration compressor protects against liquid in the cylinder.

Starting a Rotary Pump

• When starting a rotary pump, ensure the discharge valve is open.

Stuffing Box to Prevent Air Ingress

• A stuffing box equipped with a seal cage prevents air ingress.

Graphite/Grease in Packing Material

• Graphite or grease are incorporated into packing material as a lubricant, referred to as saturant.

Centrifugal Pump

• A centrifugal pump consists of an impeller surrounded by a casing.

Packing Size Determination

• Use of 13 mm packing should be used for a pump gland using a stuffing box bore of 8.4 cm and a pump shaft diameter of 5.8cm.

Double-Acting Pump

• A double-acting pump is a positive displacement pump.

Priming a Water Pump

• Priming a water pump involves filling the pump casing and suction line with water.

Intercoolers Function

• Intercoolers cool air between stages.

Single-Stage Reciprocating Air Compressors

• Single stage reciprocating air compressors consist of one or more cylinders of the same size

Installation of Pump Wear Rings

• Pump wear rings are installed on an impeller using set screws, threading, or shrinking.

Power Required for Compression with Intercooling

• Cooling air between stages decreases the power required for compression.

Factors Affecting Mechanical Seal Materials

• Pressure, type of fluid, temperature, and sealing design affect the materials used for mechanical seal mating surfaces.

Air Receiver Requirements

• Air receivers must have a safety valve.

Start/Stop Control Method for Air Compressors

• A start and stop control method for an air compressor should only be used on an electric motor-driven unit.

Determining Compressor Type

• The maximum operating pressure required is a determining factor for compressor type.

Purpose of Lantern Ring in Pump Packing

• A lantern ring in pump packing distributes the sealing water to the packing.

Turning on Cooling Water for Air Compressor

• Cooling water for an air compressor should be turned on before starting the compressor.

Driving Emergency Backup Compressors

• Emergency backup compressors are usually driven by an internal combustion engine.

Liquid to a Lantern Ring

• The liquid to a lantern ring keeps the air out of the pump.

Component to Prevent Leakage

• A wearing ring is used to prevent leakage between stationary parts of the pump and the hub of the rotating impeller.