In rocket engineering, success is often determined not only by the big picture, but above all by the quality in the details. This is exactly what is demonstrated by the distribution block for nitrous oxide in the BLAST project by HyEnD. High pressures, critical fluids such as nitrous oxide (N₂O) and ethanol, and precision manufacturing come together here. A combination in which threads do not simply connect, but must reliably seal and function permanently.
The distribution block performs several functions simultaneously. This significantly increases the requirements for the threads – both in terms of precision and sealing.
For some time now, we at VÖLKEL Threading Solutions have been supporting the student team at the University of Stuttgart in the development of their hybrid rocket and are gaining very concrete insights into what really matters in such applications.
The Distribution Block as a Central Interface
Manufactured from Aluminum 7075, the distribution block connects the nitrous oxide tank with the further piping system within the rocket. At the same time, it performs several key tasks:
- Connection to the nitrous oxide tank
- Sealing of the ethanol line
- Interface for nitrous oxide refueling
- Mounting of temperature and pressure sensors
- Integration of the emergency relief valve
- Continuation to the main line towards the valve system
During operation, pressures of up to 125 bar act on the component. Accordingly, the requirements for each individual thread are very high.
Thread Cutting Under Demanding Conditions
Aluminum 7075 is established in aerospace but presents clear requirements when thread cutting.
Surface Factor: Decisive for Sealing
Clean chip formation and a uniform surface are particularly crucial, as these significantly influence the reliable sealing of the thread. At the same time, the thread must be dimensionally accurate to ensure the long-term function of the component.
Typical challenges in practice are:
- uncontrolled chip formation
- built-up edge formation in aluminum
- tool wear
- fluctuating thread quality
Especially in a system with 125 bar, small deviations quickly become a critical factor.
Precise Threading Solution with VÖLKEL
When cutting threads on the distribution block, the HyEnD team specifically relies on tools from our company. The following are used:
- VÖLKEL Hand Tap Set G (BSP) 3/8" HSS (Art. No. 55316) with additional vaporizing
- VÖLKEL Hand Tap Set G (BSP) 1/4" HSS (Art. No. 55314) with additional vaporizing
We deliberately decided to optimize the standard untreated HSS taps with an additional vaporizing. This surface treatment reduces friction and supports clean chip evacuation. Especially with Aluminum 7075, this is crucial to achieve consistent and reproducible thread quality.
Another important point is the two-step design. The thread is not cut in one step, but built up in a controlled manner. Pre-cutting and finishing interlock cleanly and ensure uniform thread flanks.
In practice, this is directly evident: the threads are dimensionally accurate, quality remains consistent, and sealing works reliably even under high pressures. This exact combination of tool, process reliability, and result is what we focus on at VÖLKEL.
“With the taps used, we were able to work very consistently. Especially with aluminum, clean chip formation was a decisive point.”
Ben Oker, HyEnD Project Manager
Transferability into Practice
What proves itself in rocket engineering also works in many industrial applications. Wherever aluminum is used and threads must seal reliably, similar requirements apply.
Typical application areas are:
- hydraulic systems
- mechanical engineering
- prototyping
- aerospace
Here too, it becomes clear that it is not only the thread that matters, but the correct interaction of material, tool, and application.
Conclusion
The collaboration with HyEnD impressively shows how important clean thread technology is in demanding applications. The distribution block of the BLAST rocket clearly shows what matters when cutting threads: material, pressure and function place high demands on every single thread. Especially under conditions such as 125 bar, every detail ultimately matters.
With the right solutions from VÖLKEL, these requirements can be reliably implemented. The application in the HyEnD project once again confirms for us that our threading tools prove themselves not only in everyday industrial use, but also under extreme conditions.
For us, it is particularly exciting to see how our tools are used in such a complex project and function reliably there. We are pleased to be part of this project and to continue supporting the HyEnD team on their journey.
