Leak testing for pressurized systems
Rocket engines—whether capsule engines, attitude thrusters or main engines—are full of valves: fuel line valves, check valves and pilot valves, to name only a few uses. Alicat pressure controllers support rocket development by characterizing and leak testing valves.
For some—because we provide super-fast devices and amazingly quick customization engineering—Alicat is an indispensable vendor in a mission-critical function. A rocket with a leaking valve that’s supposed to be closed might be catastrophic.
Leak test mission-critical aerospace components with Alicat pressure controllers that can control pressures up to 3000 psi.
For leak checking smaller test volumes, such as valves or sensors, a single Whisper MCW-Series mass flow controller that is set to control for pressure will maintain a constant pressure at the DUT while providing accurate mass and volumetric flow readings in real time. Configured this way, the Whisper serves the functions of both a pressure controller and a mass flow meter in one device. makes leak checking for small volumes even faster…and simpler.
Pitch, roll and yaw on a satellite using pressure controllers
When an astronomical telescope satellite was the payload for a rocket launch, the challenge was aiming the ‘scope without causing so much vibration that the imaging system would blur. Using pressurized Argon through nozzles for thrust, Alicat pressure controllers were chosen for the launch because of their high resolution control and smooth ramping.
Liquid cooling systems
Alicat liquid meters have been used to measure and monitor flowing water used in cooling propulsion systems.
Another aerospace manufacturer has used portable Alicat liquid meters to monitor liquid cooling systems built into a pressure suit. Being able to test the cooling system while it was running meant attaching the portable meters to the pressure suit itself. To reduce mass, and thus the burden to the crew member (and the lifting craft), the customer ordered aluminum flow bodies instead of steel. Another customization for the pressure suit application was that we rounded the machined corners of the device to improve its compatibility with the pressure suit fabric.
Working like a Martian
What’s 95% CO2 and 0.087 psi (6 millibar) at ground level? The atmosphere of Mars. If you’ve ever marveled at the longevity of some of NASA’s Mars probes, it shouldn’t surprise you that engineers replicate atmospheric conditions there to test instrument performance before sending those payloads to the edge of human reach.
Because Alicat instruments are durable, versatile and laboratory-precise, they have been chosen to help mix gases and regulate pressure to mimic atmospheric conditions on Mars, helping to test and prove some of our most remote exploration concepts. Combine mass flow and pressure control to replicate the atmospheric conditions on Mars to test instrument performance in harsh Martian conditions.
Upper atmosphere testing
High Altitude Balloons, used to study weather patterns and understand aspects of the upper atmosphere, are filled with helium or hydrogen. They must have carefully quantified masses of buoyant gas, to provide the desired lift. Too much and the balloon fails to become neutrally buoyant, rises too high and bursts. Too little and the balloon doesn’t have enough lift for the desired altitude.
A common method to assess buoyancy is to use weights and scales on the ground to measure lifting force. But this is grossly inaccurate and cumbersome compared to an Alicat mass flow controller with a totalizer function.
Alicat meters have been used by high altitude balloon teams to more precisely reach altitudes over 100,000 feet and to attempt a 6000 mile trip across the Atlantic ocean.
Oxygen masks and life support systems
Commercial and military airplanes need to ensure that life support systems flow the correct amount of gas and meet safety regulations.
In commercial flights, the simulations are for loss of cabin pressure, which means flow is into a sub-atmosphere condition. Conditions are variable in that altitude will determine the amount of draw from venting to atmosphere. The number of seats which are being serviced with oxygen are variable by plane type. Having an Alicat device with a large turndown ratio makes this system easier to build, program and pay for.
Military aircraft manufacturers audit and quality control oxygen masks using MCD devices to simulate the inhaled and exhaled amounts of gases in a complete breath. MCD simulates the breathing of crew at high flow rates. The issues of inflow and outflow are resolved with a single instrument.
In both cases, Alicat instruments’ ability to report mass flow and gauge pressure in a single unit also aids in reducing components.