BHI Hydraulic-Pneumatic Buffers — Twice the Energy in the Same Bore, 4 to 720 kJ
Landing-gear derived technology. Oil and nitrogen absorb the impact together, giving more than double the energy of other structures in the same cylinder diameter and stroke.
What the BHI Series Is For
BHI came out of aircraft landing gear, and it still behaves like it. Hydraulic oil and nitrogen gas absorb the impact energy together: the oil handles the damping, while a nitrogen chamber stores part of the energy as potential energy and drives the return stroke.
The result is more than twice the energy absorption of other structures at the same cylinder diameter and stroke, plus a return force far larger than any other series. That combination is exactly what an end-of-track stop or a port crane emergency brake needs — high energy in a tight space, and a positive return afterwards.
Alongside port machinery, railway end-of-track stops are the second reference application for this series. Both are designed to meet OSHA, AISE, CMMA, DIN and FEM requirements.
Hydraulic-Pneumatic Synergy
An isolating piston separates the oil column from the nitrogen chamber. On impact, oil is metered through the orifice stack while the nitrogen compresses — so part of the kinetic energy is dissipated as heat and part is stored as gas pressure. The stored energy then drives the return stroke, which is why BHI has the strongest recoil of any series.
Performance &Advantages
OSHA / AISE / CMMA / DIN / FEM compliant. Special epoxy-painted cylinder and hard-chrome-plated piston rod for outdoor and corrosive service. 60 cycles/hour maximum.
Compact, high energy
More than twice the absorption of other structures in the same bore and stroke.
Built around your data
Custom orifice pattern designed for your application.
Certified design
Meets OSHA, AISE, CMMA, DIN and FEM requirements.
Strong return force
The nitrogen chamber drives the rod back harder than any other series — ideal for rail end stops.
Emergency braking
The reference choice for port machinery and railway end-of-track stops.
Outdoor and corrosive duty
Special epoxy paint system and hard-chrome-plated piston rod as standard.
Accessory range
Piston rod bellow and safety chain available.
-35 °C to 100 °C
With the special seal and hydraulic oil package, up from -10 °C to 60 °C.
Custom design service
Our engineers will size and configure the unit against your drawings.
Model Selection
Select by stroke and energy per cycle, then confirm with the maximum energy per hour. If your duty cycle is demanding, send us the numbers and we will run the calculation for you.
| Model Group | Stroke Range (mm) | Max Energy/Cycle (kJ) | Cylinder Ø (mm) |
|---|---|---|---|
| BHI65 | 50 – 100 | 4 – 8 | Ø65 |
| BHI85 | 50 – 100 | 8 – 16 | Ø85 |
| BHI100 | 50 – 800 | 10 – 132 | Ø100 |
| BHI120 | 100 – 1000 | 32 – 260 | Ø120 |
| BHI130 | 250 – 800 | 100 – 270 | Ø130 |
| BHI150 | 115 – 1000 | 62 – 510 | Ø150 |
| BHI180 | 100 – 1000 | 80 – 720 | Ø180 |
Model group shown as BHI <bore >×<stroke >— for example BHI120×200. Add the mounting code (FF / FR) and options (SC / PB).
Mounting Arrangements &Accessories
Front flange (FF) and rear flange (FR) are the standard arrangements for this series. Add a safety chain on any installation above 2 m height.
Accessories
Installation &Maintenance
- Use the buffer as an end stop.
- Remove the steel strike head.
- Exceed the permitted side load angle.
- Paint the piston rod or the body.
- Place it near acids, solvents or soluble cutting oil.
- Expose it to open flame — the unit is oil filled.
- Keep the nitrogen chamber between 3 and 10 bar. Standard factory setting is 5 bar.
- Check and top up through the gas filling nozzle under the bolt at the top of the piston rod.
- Use nitrogen. If another gas is used it must be free of salt and moisture.
- Close the knob by turning right; loosen by turning left.
- Charging sequence: set the cylinder to 3–5 bar, fit the tyre-type nozzle, turn the knob right to close, then remove the nozzle and refit the cap.
- Inspect every 6 months on safety and emergency duty, monthly in frequent service.
Send Us Five Numbers — Get a Sizing Report in 48 Hours
Every BHI unit is configured against your application data. Give us these five values and our engineers will return a recommended model with verified shock-force versus stroke and deceleration versus stroke curves. Free, and with no commitment to buy.
- W kg · moving weight
- V m/s · impact velocity
- Fp N · driving force
- n pcs · buffers in parallel
- Cycles / hour
BHI Series FAQ
Part of a Complete Crane Rail System
Hydraulic buffers are one component we supply. The same engineering and manufacturing team also delivers the rest of the runway system:
- Crane rails — rail sections for crane runway systems
- Rail clips — bolted and welded fastening systems
- Rail pads — vibration and impact damping
- Sole plates — rail support and load distribution
- Rail grouts — cementitious bedding for rail fixings
- Custom machining — molds and precision machined parts
Talk to an Engineer
Tell us your application and we will come back with a recommendation, a sizing calculation and a quotation. If you are still at the design stage, we are happy to work from drawings.
