A grease keg pump is an air-operated dispensing unit built around the 120 lb (50 kg) standard keg: big enough to skip constant cartridge refills, small enough to wheel between machines or load onto a service truck. An air motor multiplies inlet pressure through a fixed ratio (typically 45:1, 50:1, or 60:1) and pushes grease through a high-pressure hose to a control gun. For the wider pump family, see our complete guide to grease pumps.
Typical Specifications
| Parameter | Typical Value |
|---|---|
| Container | 120 lb (50 kg) standard keg; follower plate OD must match keg inner diameter |
| Pressure ratio | 45:1 / 50:1 / 60:1 |
| Max outlet pressure | typically 4,500 – 6,000 psi (310 – 415 bar), depending on ratio and air supply |
| Air inlet pressure | typically 60 – 150 psi (4 – 10 bar) |
| Grease grades | NLGI #0 to #2 standard; NLGI #3 with heated follower plate |
| Grease outlet port | typically 1/4″ BSP or 1/4″ NPT |
| Air inlet port | typically 1/4″ or 3/8″ BSP/NPT |
| Outlet hose | 1.5 – 4 m, depending on kit |
How It Works
The pump tube drops through a sealed, vented keg cover, and a follower plate sits on the grease surface, descending as the keg empties to keep the inlet primed and air out of the line. Outlet pressure follows a simple rule: inlet air pressure multiplied by the pump ratio. On a 50:1 unit, 100 psi x 50 = 5,000 psi at the grease outlet. Plate sizing and seal options are covered on the follower plate page.
What Is Supplied
A typical kit includes the air-operated pump unit (air motor plus pump tube), a keg cover with vent port, a follower plate, a high-pressure outlet hose, a Z-swivel fitting, and a grease control handle or pistol-grip dispensing valve. Selected kits also include a trolley.
Where a Keg Pump Fits
- Small workshops with daily but not continuous greasing
- Service trucks and field maintenance, where the keg travels to the machine
- Agricultural operations servicing equipment in the yard
- Maintenance teams sharing one pump between several lines
If you grease many points every shift from one fixed location, a 55-gallon drum unit cuts changeovers further; the first FAQ below covers that choice.
Limits to Check Before You Order
- Thread standards. BSP and NPT are not interchangeable; the thread angles differ (55° vs 60°), and forcing a mismatch damages threads and causes leaks.
- Stiff grease. NLGI #3, especially at low temperature, typically requires a heated follower plate or pre-warming the keg indoors.
- Hose rating. The outlet hose must be rated at or above the pump’s maximum outlet pressure, not the air inlet pressure.
- Air quality. The air supply should be filtered and regulated through an FRL unit; dirty or wet air wears air-motor seals faster.
Send us your grease grade, keg dimensions, and compressor output, and we will confirm fit before you order. Request a keg pump quote.
Frequently Asked Questions
Keg pump, 55-gallon drum pump, or manual gun: how do I choose?
Match the container to consumption. A manual gun suits a few points serviced occasionally. A keg pump suits intermittent daily use, small shops, and mobile work with a 120 lb (50 kg) keg. For continuous fleet or production-line greasing, the 55-gallon drum grease pump reduces changeovers.
What does the pressure ratio mean?
The ratio is the mechanical advantage between air motor and grease piston. A 50:1 pump turns 1 psi of inlet air into 50 psi of outlet pressure: 100 psi x 50 = 5,000 psi. Higher ratios, commonly up to 60:1, suit stiffer grease and longer hose runs.
Are BSP and NPT fittings interchangeable?
No. BSP uses a 55° thread angle and NPT uses 60°, so mixed fittings will not seat correctly and can strip. Confirm the thread standard for both ports before ordering hose assemblies.
Can a keg pump handle NLGI #3 grease?
NLGI #0 through #2 are the standard range. NLGI #3 typically requires a heated follower plate, and in cold conditions you may also need to pre-warm the keg before pumping.
How important is follower plate fit?
Critical. The plate outer diameter must closely match the keg inner diameter. A plate that is too small lets grease bypass the edge and lets air reach the inlet, causing sputtering output and wasted grease at the bottom of the keg.
What air supply do I need?
Typically 60 to 150 psi (4 to 10 bar) of regulated shop air, filtered through an FRL unit. Running below the minimum reduces output; running above the maximum risks seal and motor damage.
What port sizes come on the pump?
The grease outlet is typically 1/4″ BSP or 1/4″ NPT, and the air inlet is typically 1/4″ or 3/8″ BSP/NPT, depending on model. Confirm both before ordering to match your hose and gun fittings.
How long is the outlet hose?
Kits typically include 1.5 to 4 m of high-pressure hose. Longer runs increase pressure drop at the gun, so match hose length to your working distance.
Can I move one pump between several kegs?
Yes, that is the main advantage of the keg format. Lift the pump and follower plate out, wipe the plate edge, and seat it in the next keg. If the new keg holds a different grease type, clean the pump and hose first.
Who supplies this pump and how do I order?
IsoHiTech Lubrication Systems supplies keg pumps, follower plates, hoses, and fittings for bulk grease dispensing, founded in 2023, engineering since 2006. Email your keg dimensions, grease grade, and air supply to inquiry@isohitech.com, or ask for a configuration check.
