In the world of aerospace, where even the smallest mistake can be catastrophic, every part matters. One of those parts is the pressure vessel. These unsung heroes keep fuel, oxygen, and other vital materials safe and stable under extreme conditions. While they might seem like simple containers, their role in keeping aircraft, spacecraft, and their passengers safe is anything but simple.
Sherwood Engineering’s expertise in engineeri design services has contributed to safe and innovative pressure vessel solutions for high-risk environments like aerospace. The way these vessels are built, tested, and handled is a combination of science, engineering, and strict safety rules. Let’s take a deep dive into how pressure vessels are used in aerospace and why they matter more than ever.
What Is a Pressure Vessel?
A pressure vessel is a closed container. It holds gases or liquids at a pressure different from the outside air. In aerospace, this can mean anything from holding liquid hydrogen fuel in rockets to storing breathable air for astronauts.
But it’s not just about storing things. Pressure vessels must keep everything stable under intense temperatures, high speeds, and wild changes in pressure. If they fail, things go wrong—fast.
There are many kinds of pressure vessels. Each is built with specific materials, shapes, and purposes in mind. Some need to be lightweight. Others need to handle extreme heat. Most need to do both.
Explore different types of pressure vessels and their applications to see how they serve unique functions across air and space travel.
Where Are Pressure Vessels Used in Aerospace?
You’ll find pressure vessels throughout aircraft and spacecraft systems. In rockets, they store cryogenic fuels like liquid oxygen and hydrogen. These fuels need to be kept cold and under control, or the whole mission’s in danger.
In satellites and space stations, vessels hold things like nitrogen, helium, or breathable air. These are often used to control pressure, operate mechanical systems, or support life in space.
On commercial planes, they help run hydraulic systems. These systems control the landing gear, flaps, and brakes. Without pressure vessels doing their job, none of these systems would work.
Now take spacecraft like the Orion or Crew Dragon. These have high-pressure vessels tucked into their core systems. They’re built to survive zero-gravity, micrometeoroids, and wild temperature swings between sunlight and deep shadow.
You can dig deeper into the design criteria and failure modes of pressure vessels to understand how engineers make these systems safe and efficient under harsh conditions.
How Are Pressure Vessels Designed for Safety?
Designing a pressure vessel for aerospace isn’t just about making it strong. It’s about knowing where it could break, and why. Engineers use special software to simulate stress, temperature, and pressure changes before a vessel is even built.
First, they choose the right shape. Cylinders and spheres are common because they spread pressure evenly. Then they pick a material. Titanium alloys are popular in aerospace because they’re strong, light, and handle heat well.
Next, they plan for failure. Yes, really. Engineers study how vessels might crack, deform, or leak. They design backups, safety features, and ways to reduce damage if something goes wrong.
They also consider corrosion, fatigue, and long-term wear. Even tiny flaws in the metal or welds can grow into big problems over time.
Want to reduce risks? Follow these safety tips for handling pressure vessels that apply to every step—from design to operation.
Common Materials Used in Aerospace Pressure Vessels
Aerospace-grade pressure vessels can’t be made with just any metal. They need to be light, tough, and resistant to both heat and corrosion. Here are the top materials used today:
- Titanium Alloys: High strength, low weight. Great for spacecraft.
- Aluminium Alloys: Used in aircraft for their lightweight properties.
- Stainless Steel: Offers strength and good corrosion resistance.
- Carbon Composites: Ultra-light, used in modern spacecraft tanks.
Choosing the right material depends on what the vessel will hold, where it will go, and how long it needs to last. Composite vessels are growing in popularity because they offer great performance without extra weight.
For example, SpaceX uses carbon overwraps for its pressure vessels. These layers make tanks both lighter and stronger than traditional all-metal designs.
Manufacturing Techniques: How Are They Made?
Making a pressure vessel isn’t like making a car part. Every weld, curve, and layer matters. Most aerospace vessels are built using precision methods like:
- Spin forming: Spins metal at high speed to shape it smoothly.
- Filament winding: Wraps fibres (usually carbon) around a core.
- Electron beam welding: Joins metal without contact, perfect for tight tolerances.
After manufacturing, vessels go through a series of tests: pressure tests, burst tests, X-ray inspections, and more. Any flaw found during this stage means the vessel won’t fly.
Modern tech like 3D printing is starting to change the game. Additive manufacturing allows engineers to build complex shapes that weren’t possible before. This could mean lighter tanks, fewer parts, and safer systems in the near future.
Case Study: Pressure Vessels in the SpaceX Falcon 9
One standout example is the composite overwrapped pressure vessels (COPVs) used in SpaceX’s Falcon 9 rocket. These vessels store helium to pressurise the rocket’s fuel tanks during launch.
Back in 2016, one COPV failed during a routine test, leading to a major explosion. The issue? Frozen oxygen had seeped into tiny cracks between the carbon wrap and the metal liner. It ignited when the tank was pressurised.
Since then, SpaceX changed its COPV design. They now use updated materials and layering methods to stop cold oxygen from getting trapped. This change improved reliability and helped the company return to flight safely.
That’s a clear lesson in how even small design flaws can lead to big problems in aerospace—and how innovation can fix them.
Risks and Safety Challenges
Aerospace pressure vessels face threats that don’t exist on the ground. These include:
- Rapid temperature shifts: Spacecraft can swing from +120°C in sunlight to -100°C in shadow.
- Vibration and shock: Rocket launches rattle everything inside.
- Corrosive fuels: Some fuels eat away at metal if not stored correctly.
- Pressure cycling: Constant fill-and-empty cycles can cause fatigue cracks.
To stay safe, aerospace firms use redundant systems and smart sensors. These detect small leaks, track pressure changes, and flag problems early.
Maintenance is also strict. Ground crews inspect vessels regularly. Anything questionable is replaced—no exceptions.
Future of Pressure Vessels in Aerospace
The future of aerospace pressure vessels is lighter, smarter, and greener. Here’s what’s on the horizon:
- Smart tanks with built-in sensors to monitor stress, pressure, and temperature in real time.
- Hydrogen-fuel compatibility, with tanks designed to store this next-gen green fuel safely and efficiently.
- Reusable vessels that can handle more flight cycles with less wear.
- Self-healing materials to seal minor cracks without human help.
There’s also growing interest in additive manufacturing. 3D-printed pressure vessels might soon become the norm, offering better performance and faster production.
As we move toward long-term space travel and commercial spaceflights, the need for safer and smarter pressure vessels will only grow.
Industry Best Practices and Regulations
Strict rules guide how pressure vessels are made and tested. Here are a few standards used in aerospace:
- ASME Boiler and Pressure Vessel Code (BPVC)
- NASA-STD-5009 for spacecraft
- ISO 11120 for transportable gas cylinders
- ECSS Standards for European space systems
Meeting these isn’t optional. Regulators require detailed documentation, full traceability of materials, and proof of compliance at every stage.
Companies that don’t follow these rules face heavy fines, failed launches, or worse—lives lost.
FAQs
1. Why are pressure vessels so important in aerospace?
Pressure vessels hold fuels, gases, and life-support elements needed in flight or space. Without them, missions wouldn’t be possible. They make sure dangerous materials stay contained under pressure, even when temperatures or gravity change.
In a rocket, for example, fuel tanks double as structural parts of the vehicle. They’re not just storage—they help hold the rocket together. If one fails, the whole mission can go down. In space stations, vessels store breathable air and water. They manage pressure differences between the inside and the vacuum of space.
These vessels make sure both machines and humans survive the ride.
2. What makes aerospace vessels different from industrial ones?
Aerospace pressure vessels need to be light and compact. In a factory, a tank might weigh a tonne and sit still. In space, every gram costs money and space is tight. That’s why materials like titanium and carbon fibre are used instead of steel.
Aerospace vessels also face harsher conditions. They must survive high-speed impacts, space radiation, and long-term pressure cycles. Testing and quality control are much stricter too. There’s no fixing a tank once it’s in orbit.
3. How are pressure vessels tested before use?
Every vessel goes through a series of inspections:
- Hydrostatic testing: Filled with water and pressurised to check for leaks.
- Burst testing: Pressurised until it fails, to see where and how it breaks.
- Ultrasound and X-ray scans: Look for hidden cracks or flaws.
- Thermal cycling: Exposes the tank to extreme heat and cold to simulate space.
All results are logged and checked. Only vessels that pass every test get approved for flight.
4. Can pressure vessels be reused?
Yes, but only if they pass re-certification tests. SpaceX, for example, reuses COPVs in its Falcon 9 rockets. These are checked after every flight. Engineers scan for signs of fatigue or damage. If the vessel still meets all safety standards, it can fly again.
Reusable vessels are a big focus right now. They save cost and cut down on waste. But safety is always the top priority.
5. What happens if a pressure vessel fails in space?
It depends on what’s inside. If it holds air, a leak could cause decompression. If it holds fuel, it might trigger an explosion. That’s why engineers build backups and safety valves into every system.
In some cases, astronauts can patch small leaks. Larger failures might need emergency shutdowns or mission aborts. That’s why design, testing, and monitoring are so important. Every possible failure is studied before the vessel ever leaves Earth.
Keeping Aerospace Safe, One Vessel at a Time
Pressure vessels might not be flashy, but they’re vital. They hold the fuel, air, and fluids that keep things moving. Without them, no plane would fly, no rocket would launch, and no astronaut would survive.
As technology moves forward, we’ll see smarter designs, better materials, and even vessels that fix themselves. But the goal remains the same—keep people safe, systems working, and missions going.
For reliable pressure vessel solutions designed with precision, visit Sherwood Engineering and see how they’re shaping aerospace safety today.
Give us a call at (02) 9437 3566 or leave an enquiry if you would like to learn more about our pressure vessel engineering design and support services.