Overview
A bent pipe grease gun is an air-operated grease gun with a rigid delivery pipe bent at 45° or 90° instead of straight. It serves confined-space lubrication, where guards and tight clearances keep a straight pipe from lining up with the fitting head. Compressed air drives a ratio pump, and grease travels through a reinforced hose to the bent pipe and nozzle.
IsoHiTech supplies aftermarket-compatible components; references to fitting or nipple standards are for compatibility description only.
The assembly suits drum and bucket mount systems from 16 kg to 220 kg with pump ratios of 50:1, 60:1, or 70:1, and handles greases up to NLGI #2. Tell us your pump model, drum size, and access constraints when you request a quote.
Declared Specifications
| Parameter | Specification |
|---|---|
| Maximum operating pressure | 10,000 PSI (689 bar) |
| Recommended working pressure | 3,000-8,000 PSI (207-552 bar) |
| Air inlet | 1/4″ BSPP (G) or NPT |
| Grease flow at 6 bar air supply | 0.8-1.5 kg/min (ratio-dependent) |
| Pump ratios | 50:1, 60:1, 70:1 |
| Drum or bucket capacity | 16-220 kg (drum/bucket mount) |
| Pipe bend angle | 45° / 90° (model dependent) |
| Overall length (air inlet to nozzle tip) | 400-600 mm |
| Weight (without hose) | 1.2-1.8 kg |
| Grease consistency | NLGI #0-#2 |
| Trigger actuation force | 15-25 N |
| Body material | 6061-T6 aluminum or forged steel |
| Seals | NBR standard, FKM optional |
| Nozzle coupler | 4-jaw hydraulic, 1/8″ NPT(f) |
| Coupler compatibility | Fits nipples made to DIN 71412 |
| Supply hose inner tube | NBR, ID 6-8 mm |
| Hose reinforcement | 2-layer steel wire braid, burst 40,000 PSI |
| Hose outer cover | OD 16-19 mm, -30°C to +100°C |
| Hose length | 450-600 mm (custom lengths available) |
| Hose minimum bend radius | 75 mm dynamic, 50 mm static |
| Pump piston / stroke / output | 40-65 mm / 120-180 mm / 80-150 cc/stroke |
Declared output values for the 50:1 and 60:1 pump ratios:
| Air Supply Pressure | Output at 50:1 | Output at 60:1 | Flow Rate |
|---|---|---|---|
| 4 bar (58 PSI) | 2,000 PSI (138 bar) | 2,400 PSI (165 bar) | 0.6 kg/min |
| 6 bar (87 PSI) | 4,000 PSI (276 bar) | 4,800 PSI (331 bar) | 1.0 kg/min |
| 8 bar (116 PSI) | 5,800 PSI (400 bar) | 7,000 PSI (483 bar) | 1.4 kg/min |
| 10 bar (145 PSI) | 7,200 PSI (496 bar) | 8,700 PSI (600 bar) | 1.6 kg/min |
Working Principle and Selection
The gun mounts on a pneumatic grease pump and connects through a 1/4″ air inlet in BSPP (G) or NPT. Opening the trigger valve pushes grease through the supply hose to the nozzle coupler, a 4-jaw hydraulic type on a 1/8″ NPT(f) thread that locks onto the nipple. The coupler fits nipples made to DIN 71412; see our 4-jaw grease coupler page for details.
Choose the bend angle from the access geometry: 45° for points approached at an angle, 90° for points reached square from the side. Choose the pump ratio by the pressure the point needs: 50:1 for general lubrication, 60:1 or 70:1 for higher-pressure points. The body is 6061-T6 aluminum or forged steel, with NBR seals standard and FKM optional.
Installation and Use
Feed the gun with clean, regulated compressed air; a line-mounted filter and regulator are recommended. Tighten each joint to the torque below, sealing threads with PTFE tape or paste.
| Connection | Thread | Torque |
|---|---|---|
| Air inlet | 1/4″ NPT | 15-20 Nm |
| Hose to extension | 1/4″ NPT | 12-18 Nm |
| Nozzle assembly | 1/8″ NPT | 8-12 Nm |
| Swivel joint, if fitted | 1/4″ NPT | 18-22 Nm |
In use, seat the coupler squarely on the nipple and pull the trigger; actuation force is 15-25 N. Release and bleed residual pressure before disconnecting. Keep the hose above its 75 mm dynamic or 50 mm static minimum bend radius, and never exceed the 10,000 PSI maximum operating pressure.
Applications
Typical work includes fleet chassis points behind suspension and driveline parts, marine engine rooms with fittings close to bulkheads, guarded bearing points on industrial machinery, and grease points deep inside equipment frames. The bent pipe reaches the fitting without guard removal or awkward wrist angles.
Maintenance
No fixed service calendar is declared, so maintain by inspection. Before each use, check the hose for cuts, abrasion, or bulging, confirm the joints are tight, and make sure the coupler jaws return freely. Watch for seepage and pulsing flow. Replace the hose, seals, or coupler when inspection shows damage, leakage, or weak grip.
FAQ
What is a bent pipe grease gun?
It is an air-operated grease gun whose rigid delivery pipe is bent at 45° or 90° rather than straight, so the nozzle can reach grease fittings in confined spaces where a straight pipe cannot align.
Do the 45° and 90° angles refer to the grease fitting?
No. Here the angles describe only the gun’s rigid pipe geometry. Grease nipples come in their own angle patterns; pick the pipe bend to fit your access space, not the fitting type.
What air supply does the gun need?
Clean compressed air at the 1/4″ inlet, in BSPP (G) or NPT, with a filter and regulator recommended. Grease flow depends on the pump ratio: at 6 bar air, 0.8-1.5 kg/min.
Which pump ratio should I choose?
50:1 suits general lubrication points; move to 60:1 or 70:1 when the application needs higher grease pressure.
Why is grease flow lower than expected?
Check the air source first, since low or unsteady air pressure cuts output. Confirm the grease is within NLGI #0-#2, and check the nozzle and pipe for blockage; weak flow with correct air and grease usually means worn seals.
What causes pulsing or erratic flow?
Pulsing usually means trapped air in the grease path or grease too stiff for the conditions. Bleed the line, confirm the grade, and raise air pressure within the declared range.
What should I do if grease seeps from a joint?
Stop and re-tighten the joint to the torque in the installation table. If seepage continues, reseal the thread and replace worn seals rather than running on.
Which grease nipples will the coupler fit?
The 4-jaw nozzle coupler fits nipples made to DIN 71412, including sizes such as our M10 grease nipples. Match the coupler to the nipple size on your equipment.
Is the 40,000 PSI hose rating a working pressure?
No. 40,000 PSI is the declared burst rating of the steel wire braided hose, not a working pressure. Normal operation stays within the recommended 3,000-8,000 PSI working range.
Who can help me configure a gun for my plant?
Contact IsoHiTech Lubrication Systems – founded in 2023, engineering since 2006 – at inquiry@isohitech.com, or contact our engineering team with your pump ratio, drum size, and access constraints.
