Oh look a grease gun, did they use it in the PM Program at Work?

A grease gun is typically used in industrial worksites and places plus home garages to keep items lubricated.  The bigger question is not if you have a grease gun on site, the LARGER QUESTION should be did anyone teach you how to work it, load it and not miss use it!

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.

It is important to know precisely how much lubricant needs to be applied per cycle and how much lubricant the grease gun will produce per shot. Grease guns can produce between 1 gram and 1.5 grams per shot. This can result in significant over-lubrication per point unless the output is known, to add the amount of grease as determined by the SKF formula G = DB/10, where G is grease in ounces, D is bearing outer diameter, and B is bearing width

Grease guns are capable of producing several thousand psi per stroke. This kind of pressure can certainly blow out bearing seals and shields. If a careless approach is taken when using the grease gun, then it is highly likely that the equipment will be over pressurized and over lubricated. When this occurs, particularly with a bearing, then the likelihood that the bearing can see its rated lifecycle is greatly reduced.

Several factors influence the quantity of grease that would go into a bearing at the selected interval. Critical factors include:

1. Design of the bearing (plain, roller, ball or spherical roller).
2. Type of shield used in the bearing.
3. Size and speed from which to calculate dN values.
4. Viscosity of the lubricant in the grease.

Whether the gun is filled with oil or grease, the practitioner should be precise with the use of the gun, beginning with an analysis of the bearing dimensions and calculation of the required amount of grease per cycle, followed by an analysis of the amount of output per cycle of the gun.

Grease Gun Best Practices

• Calculate the proper amount of grease needed for the relubrication 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.

Regreasing Frequency

Managing regreasing frequencies to optimal conditions is necessary to avoid long-term machine health problems. If the frequency is too long, symptoms may include lubricant starvation, which promotes wear, friction and grease contamination. If the frequency is too short, excessive grease consumption and safety and environmental issues may occur.

Overgreasing and Undergreasing

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.

When working the grease gun lever arm, never hold the nozzle onto the grease fitting. Also, when cycling the lever arm, be conscious of the risk of overpressurisation and do not force the lever arm if there is strong back pressure.

Use the following tips to maintain your grease guns and fittings.

• Wipe the fitting before use to clear debris. Use a clean shop rag or lint-free cloth to clear debris.
• Inspect the grease fitting. Replace defective or damaged fittings.
• Where possible, standardize on fitting type.
• Conspicuously mark the grease fitting with the type of grease being used. Avoid changes where possible.
• Learn the proper grease gun operation and know the delivery volume per shot. Have grease guns calibrated occasionally to ensure proper volume delivery.
• Some grease guns develop pressure up to 15,000 psi. Exercise caution to avoid overpacking and/or seal damage.
• Keep guns clean, avoiding laying them on dirty surfaces. Repack on a clean bench using a gun loader fitting.
• Keep grease guns covered when not in use.
• Exercise caution to ensure safety. Make changes such as piping out the fitting to avoid danger.
• When repacking grease guns from a pressure line, wipe down the fitting and the pressure line to prevent contamination. When repacking with tubes, move to an environmentally controlled area, such as a control room, to replace the tube.

There are several different kinds of grease guns, although loading them is similar for all of them. A lever grease gun will use a long lever that pushes the grease out. You will need two hands to operate this and it is by far the most common of all grease guns. A pistol grip grease gun will have a pistol-like trigger. The hand grip gun will use the pressure produced by your hand pumping. An air powered gun is much more dangerous and powerful to use. This is a type of pneumatic gun that is used in commercial industries.

Load it properly the first time every time!

1. Replace the Grease Cartridge

Many people have trouble loading cartridge grease guns. It is important that you pull back the T handle, which connects to a spring loaded rod, and latch it into place. Unscrew the head of the grease gun, break the seal and insert the cartridge into the barrel assembly. You want to screw it in tight, but not too tight. Unlatch the rod. Sometimes there may be air in the cartridge, which can cause the gun not to load. Unscrew the head a little and allow any air to escape.

1. The T Handle

The hard part comes if your T handle does not lock into place, since you will have to hold it out. This is very important and if the T handle is not fully pulled out when loading you will have issues when distributing grease. If you should have to hold the handle out with one hand and then screw in the new cartridge you will have difficulties. The easiest way to get around this is to have a friend help. If no one else is around then make sure the cap and seal are undone on the cartridge before pulling back the T rod. This way you will just have to put the new cartridge into place, and this can technically be done with one hand.

1. Loading Bulk Grease

Bulk grease can be convenient if you use a lot of grease. You do not want to refill an already used cartridge because they can easily deteriorate and ruin your grease gun. The main issue with suctioning in new grease is that it does not flow very well. This is an issue if you are vacuum filling the grease gun or using a pump. The easiest way to get around this is to warm up the grease a bit. Make sure you read the specifications so you do not heat the grease up too high. If you do not want to vacuum load the gun then you can also scoop up the grease and pack it into the new cartridge. However, this method will create many air pockets, which can cause an issue when using the gun.

1. Contaminants

You want to be very careful when loading the gun to prevent contaminants ending up in the grease. This is also a problem with grease cartridges, as metal slivers can mix in with the grease if you are not careful.