A grease gun is a garage CUM workshop tool used for lubrication. A grease gun is used to apply the lubricant through an aperture on a joint or a specific point. To deliver a precise amount of grease at a precise point these guns have a tube or a hose. The delivery end of the hose or tube puts an exact amount of grease on a fitting or nipple. There are channels behind the nipple that lead the lubrication to where it is needed. To use the grease gun correctly – you should know its parts.
The barrel is the base to which all the parts of the grease gun are attached. It is the exoskeleton that houses the grease tube or the supply from the bulk.
A grease tube also called the cartridge is inserted into the housing of the grease gun. It can be replaced when depleted.
The head is the lid that is screwed on to the barrel of the gun. It has grease pathways and valves that help pump the grease. The grease travels along these pathways from the barrel or cartridge to the fixed tube or flexible hose.
The lever – In manual models of a grease gun, the lever is used to hand-pump the grease from the barrel to the tube or hose outlet.
Trigger & handle – In manual grease guns, the hand pump has a gun like configuration that allows the user to apply a controlled amount of mechanical pressure by squeezing the trigger and handle.
The hydraulic coupler is a connector that connects the hose or the tube to the head of the gun. The coupler is on the tube or the hose and is screwed onto the head.
A flexible hose is connected to the coupler for flexible positioning to deliver grease to hard-to-reach places.
A fixed tube is a rigid hollow structure that can replace the flexible hose by unscrewing the coupler. This part allows the user to grease fittings and nipples precisely.
Filler nipple is the injection point from the grease filler pump.
Air-release nipple on the grease gun allows the air to escape while new grease is being filled into the grease gun’s head.
The plunger – There is a flat plate inside the barrel that pushes the grease into the head for smooth extrusion. It applies uniform pressure on the back end of the grease cartridge or bulk of grease in the barrel.
The spring – The plunger is spring-loaded. It applies pressure to the plunger to keep the grease collected at the head end of the barrel. This way air pockets are eliminated.
Follower rod – the piston rod or plunger rod or barrel rod – is attached to the outer bottom of the plunger disc. This rod can be pulled back along with the spring to reload the gun with a new cartridge or bulk grease.
Follower handle – The follower rod has a handle at the bottom that offers a grip while executing the operation of replacing the grease or the cartridge.
Adapters, connectors, and couplers – A grease gun may have a standard connection adapter like the hydraulic coupler. But there are variations such as the 90° adapter, three-jaw swivel couplers, a needle end adapter, etc. These couplers and adapters have varying applications.
The 90° adapter is meant to reach fittings in confined areas at a 90° bend.
The 3-jaw swivel coupler locks into various positions to facilitate various applications.
The needle-end adapter delivers precise pin-point of grease in tight places.
Fixed tube versus flexible hose – The decision of choosing the right coupler depends upon the type location and distance of the fitting. For example – if you have to reach overhead or under the sink or around the bend to reach a fitting then a flexible hose or tube should be used. Meanwhile, the grease guns with levers require both hands to pump the grease – the fixed tubes are a great alternative.
Grease fittings such as pressure-relief vent fitting, flush-type grease fitting, standard hydraulic grease fitting, Zerk fitting, alemite fitting (grease nipple), and button head fittings are used. The fitting is the lubrication point where a grease connector is connected. For standard applications, the usual hydraulic grease fitting is used. It can be fitted angled or upright.
For a couple engagement where large volumes of grease are being poured a button-head fitting is perfect. When the space is limited for standard protruding fittings then the flush-type fittings are used. To prevent pressure from building that would damage seals the pressure-relief fittings for vents are used. These fittings need to be placed correctly to prevent contamination.
Accessories such as grease gun meters may be retrofitted on the gun to optimize grease consumption. Plastic caps prevent debris and corrosion from contaminating the grease. The grease guns can be color-coded. The barrels can be transparent and be loaded with color-coded barrels to indicate different consistencies of grease. There are sonic and ultra-sonic devices used to check if the greasing has been achieved correctly.
Types of Grease Guns
To use the grease gun correctly you should know their types. This will highlight the difference between them.
Grease guns can be powered in three ways – by air, by power, and by hand. The benefits of the types depend upon their intended use and the technician’s preference. The other reason for the variation is the method by which the grease is loaded – by suction fill, bulk, or cartridge.
Manual grease guns are the most common type. They can deliver up to 1.28g of grease per pump via a hose or tube. These guns can deliver from 10000 to 15000 PSI of pressure for grease extrusion.
Manual guns are of two types – lever or a pistol grip.
Lever guns have a long handle attached to a hand pump. The lever has to be squeezed or compressed after the tubing or hose is applied to the nipple or fitting. The gun may stand on a tripod and the force applied may bear down on these legs of the tripod.
Pistol grip guns have a shorter handle and can be gripped in the hand like a gun. You can squeeze the trigger to extrude 0.86g per pump.
Pneumatic grease guns use compressed air to deliver grease via a hose or a tube. The trigger activates positive displacement and extrudes the grease. These guns are rated to 6000 PSI.
Battery-powered grease guns deliver force comparable to pneumatic guns at a low voltage. They offer the advantages of being portable as they are cordless. These guns are rated between 6000 – 10000 PSI.
AC powered guns are corded guns that connect to a power outlet. They provide a consistent flow of grease and are used as an alternative to pneumatic guns These guns are rated to 7000 PSI.
These grease guns have the above-mentioned parts and can be fitted with these couplers, adapters, hoses, etc.
How to Use A Grease Gun?
Now you know the types of grease guns and the scale of operation these facilitate. You should learn how to use them correctly. Effective lubrication requires training. This training ranges from physical activity that is required for correct lubrication to correct application. The technicians are also taught to manage misapplication, spills, and damage to the machinery.
The grease gun operator is trained on each piece of equipment they will be lubricating. They are also taught to use the various types of grease guns and the magnitude of operation they can handle. They are also made aware that grease should not be applied to machines in operation -unless the fittings are in safe-to-touch and approach places.
Never try to reach over, past, through, or under a moving part until it is still. Complete the task and maintain a proper balance and footing at all times. This facilitated better control of the tool and prevents accidents in unexpected situations. After you have loaded, unloaded, and taken apart a grease gun – you understand it’s working.
How to Operate A Grease Gun?
Place the nozzle at the fitting and squeeze the trigger or lever. Grease should extrude from the nozzle to lubricate the point. However, if at any point your grease gun does not do its function. It may be due to air pockets trapped in the grease, in the tube, or the hose.
This can be remedied by pumping the trigger or lever a few times and pressing the air release valve until the grease flows again. On smaller grease guns this can be remedied by turning the barrel a turn or two. Then the pump till the grease comes out then retighten the tube. With this know-how, you will get years of trouble-free service from your grease guns.
To achieve the best greasing and keep your gun working in optimum working condition. Purge a small amount of grease from the coupler to flush away debris Use a grease cap or leave a small grease dollop after re-greasing.
Wipe the fitting to clear all debris. Inspect the fitting and replace defective fittings. Inspect the cavity of the new fittings for burrs, debris, damage. Purge these joints and fittings using a grease gun if necessary.
You should manage the pressure while re-greasing. Slowly pump the grease into the bearing every 5 seconds releasing 0.1 ounce of grease. Or you can adjust the volume output depending on the size of the job, type of fitting, and your experience.
Discontinue greasing if you feel backpressure. This pressure develops due to a blockage usually due to a caked thickener. Grease guns can produce 15000 PSI of pressure that can dislodge lip seals that fail at 500 PSI. The pressure may also collapse shield and grease motor windings. To prevent this fit a pressure relief valve on the gun or use pressure check fittings.
For safety reasons do not hold the coupler in your hand. The grease gun can be used for re-lubrication to purge contaminants from bearings, hinge pins, connectors. The impurities enter through the seals. The new grease forces the old grease out through the seals along with the impurities.
While re-greasing bearings with fittings and vent plugs, remove the vent plug. Inspect and discharge the solidified grease with a tool such as a spatula, needle, bottle cleaner, etc. Then attach the grease gun to the fitting and pump the grease slowly. Continue pumping till the grease begins to expel from the fitting. Allow the excess grease to relieve. Only then replace the relief valve.
How to Load & Use A Grease Gun with A Cartridge
Unscrew the head of the gun from its barrel. Pull the Follower rod handle back. Now lock the Follower rod handle. Then open the new cartridge of grease. Insert this grease cartridge into the barrel of the grease gun.
There may be a pull-tag on one of the ends of this grease cartridge. Remove it to equalize the pressure within and outside the cartridge. This facilitates the flow of grease.
Push the cartridge into the barrel such that the rim of the cartridge is in touch with the rim of the grease gun. Now screw the head of the barrel but keep it loose by one turn.
Now release the Follower rod from its lock or the retaining groove. The piston plate will come to lie against the bottom of the cartridge.
Depress the Follower rod handle to force the grease into the head. This forces the air out and fills the head and connector with grease.
Now compress the lever or trigger of the pistol to pump grease into the nozzle. After some grease has been extruded and air pockets eliminated wipe the nozzle clean.
Tighten the cap on the head and push the air bleeder valve down – this forces the rest of the air out.
Now place the coupler on the extension hose and try it out on a napkin or a practice piece. After you have calibrated the amount of extrusion place the tip of the coupler at the point to be greased. Then pump the lever until the grease is extruded on to the fitting.
How to Load a Grease Gun from A Tub and Operate it
Remove the head from the grease barrel. Now place a large amount of grease in the head. Next place the mouth of the barrel into the tub of grease such that the Follower handle and rod are in your hand.
Now insert the barrel 2-inches deep into the grease barrel. Next, push down on the barrel while pulling the plunger – follower rod and handle assembly upwards towards you. This is causing the grease to be sucked into the barrel.
Lock the Follower rod when it is fully retracted or extended. Now move the barrel from side to side. This cuts out the extra grease from clinging to the barrel when it is full.
Now use a silicone spatula or glove to wipe off the extra grease and slide your hand along the side of the tub. This way you do not waste the grease. You can swipe with your hand too. The residual greasiness can be wiped off using a rag, paper towel, etc.
Now place the head on the barrel and reassemble the rest of the grease gun. Release the Follower rod from the locked position. Pump the lever to start the flow. Now place the coupler to attach the hose or tube. Calibrate and then extrude on the fitting.
How to Load a Grease Gun Using a Filler Pump & Operate it
These pumps bring you optimum cleanliness while filling your grease guns. Best
lubrication practices say that each type of grease requires an individual grease gun. And the individual refilling has to be a clean process.
Filler pumps are designed to achieve this goal. Just place the follower plate on top of the grease until the grease comes through the center hole. This helps remove air from the pump. Then fit the cover plate by tightening the screws.
Then insert the piston rod, ensure it goes to the bottom of the grease drum. Just press the filling nipple into the filling nozzle and start pumping using the lever on the piston rod.
With the high volume per stroke, your grease gun is quickly filled. Now simple lift your grease gun away from the filling nozzle. The connection is broken neatly without any drips or spills. And your gun is ready for the lubrication task after you have calibrated it as described above.
In conclusion, the dispensing options, the volumes, and the pressure of each grease gun and grease type is different. Each type of grease gun has its advantages and disadvantages. They work with specific types of grease fittings such as hydraulic or push connect fittings, button head or slide connect fittings and flush type or push connect fittings. The fundamentals of greasing fittings should be well understood besides the types of grease guns. Grease behaves differently from oil. And there are issues with over-greasing and under-greasing. Thus, before applying these guns on actual work try them out on a practice piece.