Fluid Systems

Fluid Systems owns the path from tank to injector: pressurization, propellant routing, and the valves and interlocks that make a test sequence safe to run and, more importantly, safe to abort.

From tank to injector

We bring fuel, oxidiser, and pressurant to the engine through a connected system of tanks, regulators, and plumbing. The layout has to account for both the flow paths and how the hardware fits around the test stand. Our work connects the propellant supply to the conditions the engine needs.

CAD model showing tanks, a gas cylinder, and the engine test stand with its supporting frames.

Cutaway CAD section of a propellant tank, showing the closure and its ports at the top, the propellant volume, and the outlet cone at the base.

The tanks and test stand arranged in CAD, and a propellant tank in section.

Designing the tanks

The propellant tanks are our own design rather than bought hardware. Each is a cylinder closed by a machined dome that carries the ports on its face, seals against the tank wall on a pair of O-ring grooves, and takes the bolt load through a ring of lugs around its rim. The closures start in CAD and finish on the lathe, turned from solid stock in the same shop as the engine parts.

CAD render of a tank closure: a machined dome with threaded ports across its face, a ring of bolt lugs around the rim, and two O-ring grooves below them.

A turned metal dome resting on a workbench, its face still carrying the concentric tool marks left by the lathe.

CAD render of the top of a propellant tank, with fittings, a valve, and a pressurant hose landing on the closure.

A tank closure in CAD, a closure turned on the lathe, and the fittings that land on the tank head.

Routing & control

The piping and instrumentation diagram maps how the system connects, from pressurisation to the engine inlet. Servo ball valves, three-way valves, and check valves manage the flow paths, while pressure transducers and thermocouples provide measurements. We work with Electrical & Controls to connect that hardware to the test sequence and shutdown controls.

Piping and instrumentation diagram of the fuel, oxidiser, and nitrogen systems, showing valves, regulators, sensors, and connections. — The propellant feed system. Select the diagram to view it full size.

CAD render of a valve actuator: stacked mounting plates and a linkage arm driving the stem of a threaded valve body. — One valve on that diagram, in hardware — a linkage carries the drive from the actuator to the valve stem.

Building the connections

The work comes together on the stand, where tanks, lines, valves, and sensors become one system. Fluid Systems works alongside Combustion Devices to connect the feed system to the engine, and alongside Electrical & Controls to make it operable. Shared shop work and integration bring the plumbing, engine, and electronics together for testing.

A student working at a lathe in the shared machine shop.

Test platform with connected valves, tubing, a pressure gauge, and control electronics.

A drill cutting into a cylindrical workpiece held in a lathe.

Shared shop work alongside the assembled test plumbing.