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Grease Gun Or Lethal Weapon do you know anything about Grease Gun use and risks!

In the hands of an untrained operator, a grease gun can deliver pressure up to 15,000 psi. That’s 30 times what a typical bearing seal can handle. Once the bearing seal is broken, the bearing is on its way to early failure.

Regardless if it is your company vehicle, an electrical motor onsite or plates on a centrifuge on a rig the key to any program is what you have covered in your company safety program and PM standards~

A high-pressure manual grease gun is designed to deliver from 2,000 to 15,000 psi. Applying too much pressure while greasing will damage the bearing seals, which rarely handle more than 500 psi. Symptoms of high grease gun pressure include collapsed bearing shields, damaged bearing seals, grease driven into electric motor windings, and safety and environmental issues. When it comes to re-greasing bearings, more is not always the better option and actually can be a costly mistake. Instead, greasing should be set on a frequency with proper calculations used to determine the amount of grease needed at each re-lubrication. The determining factor for the amount required is based on the dimensions of the bearing or the bearing housing.

Over-greasing can lead to high operating temperatures, collapsed seals and in the case of greased electric motors, energy loss and failures. Too much grease volume (over-greasing) in a bearing cavity will cause the rotating bearing elements to begin churning the grease, pushing it out of the way, resulting in energy loss and rising temperatures. This leads to rapid oxidation (chemical degradation) of the grease as well as an accelerated rate of oil bleed, which is a separation of the oil from the thickener. The heat that has been generated over time along with the oil bleed eventually will cook the grease thickener into a hard, crusty build-up that can impair proper lubrication and even block new grease from reaching the core of the bearing. This can result in accelerated wear of the rolling elements and then component failure.

Now image 15000 psi on the wrong places or bearing and how that caused an incident

Some factors to consider when establishing standard grease guns for your facility include:

  1. How are you going to load the grease gun – suction fill, cartridge or bulk?
  2. What are your common lubrication quantities? You do not want a high-volume grease gun for areas requiring only a few grams of grease for lubrication tasks.
  3. Where is the lubrication task being performed? Some lubrication points are easier to reach with a pistol or hand-grip grease gun than a lever and vice versa. This will also help determine where rigid extension and flexible extensions are needed.

Over-greasing and Under-greasing

It is important to know the exact amount of grease necessary for your greasing application to avoid over-greasing or under-greasing. Symptoms of over-greasing include damaged seals and motor windings, environmental issues, and fluid friction, which leads to increased heat generation, higher grease oxidation rates and higher energy consumption. Symptoms of under-greasing include bearing starvation, which results in friction wear and increased contamination. Over-greasing electric motor cavities has the same effect as with any bearing application except that grease can reach the motor windings. When filled completely with grease, an electric motor bearing will generate excessive heat due to churning. This results in energy loss as well as an accelerated rate of oil bleed and hardening of the grease thickener. Again, the high pressure applied from a grease gun can result in grease finding its way between the shaft and inner bearing cap and pressing into the inside of the motor. The result over time is the coating of the electric motor windings with grease, which leads to both winding insulation and bearing failures.

Setting up a maintenance program is key to solving the problem of over-greasing. Each lube point, whether it be a bearing housing or electric motor, should be tracked as an asset, and records kept for scheduling planned maintenance or inspections of the asset.

How Output is Measured

It is common for maintenance departments to have a wide variety of grease gun types, makes and models. This can cause grease-related disorders due to cross-contamination and inaccurate knowledge of each grease gun’s output per stroke. Grease guns are known to vary in the amount of grease that is output from 0.5 grams to more than 3 grams. This inconsistency depends on factors such as the type, model and age of the grease gun.

Once you have planned the scheduling of the assets, you will need to determine the timing and amount of grease (volume) that should be applied at each point. The volume can be calculated with a simple equation:

G = 0.114 x D x B

Where G = the amount of grease in ounces

D = the bore diameter in inches

B = the bearing width in inches

Another factor to consider is the type of grease fittings used in the facility. Most fittings have a ball check in the head of the fitting, which prevents dirt from getting to the bearing. The spherical contour of the fitting head provides a ball-and-socket joint between the fitting and the hydraulic coupler of the grease gun. The most common fitting is the hydraulic fitting, available in standard and metric sizes.

Some common tips for using a grease gun:

  1. Calculate the proper amount of grease needed for re-lubrication of bearings, based upon the calibrated delivery volume of the selected grease gun.
  2. Use a vent plug on the relief port of the bearing to help flush old grease to reduce the risk of too much pressure on the bearing.
  3. Use extreme caution when loading grease into the grease gun to ensure that contaminants are not introduced. If using a cartridge, be careful when removing the metal lid that no metal slivers are introduced into the grease.
  4. Make sure the grease gun is clearly marked to identify the grease with which it should be charged. Do not use any type of grease other than that which is identified.
  5. Always make sure the dispensing nozzle of the grease gun is clean before using. Pump a small amount of grease out of the dispensing nozzle, then wipe off with a clean rag or lint-free cloth before attaching to the grease fitting.
  6. Clean the grease fitting of all dirt before attaching the grease gun. Inspect and replace damaged fittings. Also clean the grease fitting after applying grease. It is helpful to use grease-fitting caps to keep them clean, but still wipe fittings clean before applying grease.
  7. Ensure the proper grease is used at every grease point. Applying the wrong grease can cause an incompatibility problem which can quickly cause bearing failure. Lubrication points should be clearly identified with which grease is to be used. This can be done with colored labels, adhesive dots or paint markers.
  8. Grease guns should be stored unpressurized in a clean, cool, dry area and in a horizontal position to help keep the oil from bleeding out of the grease. Grease gun clamps make storage easy and organized. Also cover the coupler to keep it free from dirt and contaminants.
  9. Calibrate grease guns regularly to ensure the proper delivery volume.
  10. Use caution and safety when working around moving equipment and when using a grease gun.

Manual grease guns have their place in industry. They have a few disadvantages, the chief of which is poor control that can lead to over- and under-lubrication. Grease guns also present a higher risk of inducing contaminants.

Grease fittings have several names such as a Zerk fitting, grease nipple or Alemite fitting. This is the lubrication point where the grease connector is attached. The standard hydraulic grease fitting is most commonly used for standard applications. It can be either upright or angled. The button-head fitting is ideal for good coupler engagement when large volumes of grease are being added. A flush-type grease fitting is preferred when space is limited for standard protruding fittings, while the pressure-relief vent fitting helps prevent higher pressures that could lead to damaged seals.

The Four Rs Of Lubrication in your PM program in Safety

Right lubricant,

Right time,

Right quantity

and Right place.

 If these four basic elements aren’t properly addressed, you could be doing your equipment more harm than good. Knowledge to understand important lubricant properties and strategies to select the correct lubricant for each machine application Grease Gun Best Practices

  • Calculate the proper amount of grease needed for the re-lubrication of bearings based upon the calibrated delivery volume of the selected grease gun.
  • Use a vent plug on the relief port of the bearing to help flush old grease and reduce the risk of too much pressure on the bearing.
  • Use extreme caution when loading grease into the grease gun to ensure that contaminants are not introduced. If using a cartridge, be careful when removing the metal lid so that no metal slivers are introduced into the grease.
  • Make sure the grease gun is clearly marked to identify the grease with which it should be charged. Do not use any type of grease other than that which is identified.
  • Always make sure the dispensing nozzle of the grease gun is clean before using. Pump a small amount of grease out of the dispensing nozzle and then wipe the nozzle off with a clean rag or lint-free cloth before attaching it to the grease fitting.
  • Clean the grease fitting of all dirt before attaching the grease gun. Inspect and replace damaged fittings. It is helpful to use grease-fitting caps to keep them clean, but still wipe fittings clean before applying grease.
  • Ensure that the proper grease is used at every grease point. Applying the wrong grease can cause an incompatibility problem, which can quickly cause bearing failure. Lubrication points should be clearly identified as to which grease is to be used. This can be done with colored labels, adhesive dots or paint markers.
  • Grease guns should be stored unpressurized in a clean, cool and dry area and in a horizontal position to help keep the oil from bleeding out of the grease. Grease gun clamps make storage easy and organized. Also, cover the coupler to keep it free from dirt and contaminants.
  • Calibrate grease guns regularly to ensure the proper delivery volume.
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