When you need extreme pressure control for aerospace ground support or oilfield testing, standard commercial pumps won't cut it. You have to look at specialized American manufacturing. Hydraulics International Inc USA designs and builds high-pressure liquid pumps, air-driven gas boosters, and aerospace test systems right out of Chatsworth, California. If you're engineering a system that demands precision under tens of thousands of pounds of pressure, understanding how these components operate will keep your operations safe and compliant.
This guide breaks down what makes HII equipment unique, how their air-driven technology functions, and where these heavy-duty systems deploy across industrial sectors. You'll learn how differential working areas create massive output pressures without electrical spark risks, and what to look for when specifying pumps for your facility.
Core Engineering Principles of HII Equipment
At the heart of most Hydraulics International equipment lies a simple mechanical concept: differential working areas. Instead of relying on complex electric motor drives with high electrical draws, their pumps use compressed air acting on a larger drive piston to drive a smaller high-pressure liquid plunger or gas piston.
This setup creates a fixed pressure ratio. If you feed 100 psi of shop air into a pump with a 1:100 ratio, you can generate up to 10,000 psi of hydraulic or gas pressure.
- Intrinsically Safe: Because they run on compressed air rather than electricity, they don't produce electrical arcs. That makes them ideal for hazardous environments like offshore oil platforms or hydrogen fueling stations.
- Stall Capability: When the output pressure reaches equilibrium with the air drive ratio, the pump simply stalls. It doesn't overheat, burn out, or require bypass valves, and it holds pressure indefinitely without consuming energy.
- Modular Construction: HII manufactures roughly 85% of its components internally, using corrosion-resistant materials like 316 stainless steel and specialized seals to handle aggressive fluids like Skydrol, deionized water, or industrial gases.
Major Product Categories and Applications
Industrial facilities deploy these systems across strict operational niches. Knowing which hardware fits your application prevents costly specification errors.
Air-Driven Liquid Pumps
These units handle hydrostatic testing for valves, hoses, pressure vessels, and pipeline components up to 80,000 psi. They are self-priming and compatible with water, various synthetic oils, and solvents. Technicians rely on them for rigorous burst testing where maintaining an exact static pressure over hours is mandatory.
Air-Driven Gas Boosters
For operations working with nitrogen, helium, oxygen, or hydrogen, standard compressors fall short. HII gas boosters take low-pressure supply gas (starting around 50 psi) and elevate it up to 30,000 psi without introducing hydrocarbon contaminants.
- Aviation Support: Charging landing gear struts, accumulator bottles, and emergency escape slide cylinders.
- Diving and Safety: Filling high-pressure SCUBA, re-breather, and firefighter breathing air bottles.
- Clean Energy: Compressing hydrogen for fuel cell vehicle testing facilities.
Military and Commercial Ground Support Equipment (AGSE)
Beyond individual pumps, the company builds large-scale test benches and portable recharging carts for military and commercial aviation. These ground support units test aircraft hydraulic integrity, flush fluid systems, and supply pure nitrogen for tire inflation on heavy transport fleets. You can review official industry profiles on platforms like Aviation Pros to see their footprint in aerospace maintenance.
Selecting and Maintaining High-Pressure Systems
Choosing the right model requires calculating your required flow rate against your available air supply pressure. If you under-index your drive air volume, your pump will stall prematurely or fail to cycle at peak speed.
- Verify Fluid Compatibility: Match your working fluid with the correct seal material (such as BUNA-N or UHMWPE) and body metal (such as 15-5 PH or 316 stainless steel) to prevent premature corrosion.
- Incorporate Distance Pieces: For critical applications where toxic or reactive fluids can't risk mixing with the drive section, specify a distance piece model (such as the HII "-D" series) to provide a vented, physical separation barrier.
- Monitor Filtration: Clean drive air is essential. Even though many HII pumps are designed to run without airline lubrication, particulate matter and moisture in shop air lines will score cylinder walls over time.
To explore technical data sheets and find certified distributors, visit the Hydraulics International Official Website.
Frequently Asked Questions
Do air-driven liquid pumps require external lubrication?
No. Most standard HII air-driven pumps are engineered to run dry on the air drive side without line lubrication, which keeps exhaust air clean and maintenance minimal.
What is the maximum pressure HII liquid pumps can reach?
Depending on the specific series and pressure ratio selected, certain models can achieve output pressures scaling up to 80,000 psi for specialized testing requirements.
Can these gas boosters handle pure oxygen safely?
Yes, provided they are configured with proper oxygen-clean assembly protocols, non-hydrocarbon seals, and complete separation between the drive air and gas sections to eliminate ignition sources.
How does a pump maintain pressure without consuming power?
Once the hydraulic or gas output pressure balances with the pneumatic drive ratio, the pump stalls automatically. It holds that static pressure indefinitely using zero electrical or pneumatic energy until a pressure drop occurs.
