Liquid-Nitrous-Oxide, Temperature-Pressure-Density table from Friends of Amateur Rocketry
Linde Sponsorship
Contact: Derek Breitenstine, Derek.Breitenstine@linde.com
Keira Boone (kboone@mit.edu) and Reva Mathankar are both within an email thread from February 9, 2026 where Linde agreed to sponsor us in the form of providing N2O free of charge to the team. As of May 2026, we are planning to reach back out at the end of summer to follow up, but know that this is a possibility.
ORDER WITH A SIPHON TUBE
After three failed hotfire attempts at bluShift in 2025-2026, we learned the main reason: it turned out we'd been filling with gaseous nitrous this whole time, because there was a typo in the order. The order should've been NS RF 64S, but instead NS RF 64 was ordered which is very conveniently a nitrous tank with no siphon tube. YOU NEED A SIPHON TUBE FOR LIQUID NITROUS!!!
Because we still had 3 full cylinders of gaseous nitrous with no siphon tube, we made a quick 80/20 rectangular prism and just put that at the bottom of the gas cylinder cart so that the liquid is at the bottom (since there is no siphon tube).
photo of 80/20 structure to be added
How a siphon tube works:
A metal tube is attached to the valve and extends down to the lowest point of the bottle, and when the valve is opened, the high internal pressure (roughly 900) psi) forces the liquid nitrous up the tube and out of the valve, allowing the bottle to be used while standing upright. To work correctly, the siphon tube must be lined up with the outlet port so it points toward the bottom-rear of the bottle.
Note that some liquid may allow a successful fire at first even without a siphon tube.
If a non-siphon bottle is used, it typically dispenses gaseous nitrous because it draws from the top space. However, liquid can come out initially due to a few factors, and our current working theories are:
- Linde may slightly overfill their bottles
- There may be a partial siphon tube or fitting that goes partway down the bottle;
- Cold/High Pressure: If the tank is full and very cold, the internal pressure can fluctuate.
- Sloshing or Inversion: If the bottle was tilted, moved, or partially inverted, the liquid inside can cover the outlet port, causing liquid to be pushed out instead of gas.
- Excessive Flow Rate: Opening the valve too quickly can cause a rush of liquid, especially if the tank is very full
Gerard Desjardins' Bottle Opening Technique
Disclaimer: bluShift engineers do this for us, and it is something they are comfortable doing.
Gerard is the Lead Propulsion Test Engineer at bluShift, and he will crack the cap of the cylinder and (pointing it away from himself) open the valve to see a plume, at which point it is visually identifiable whether the plume is water or gas.