I can only find nitrogen cylinders at 30 litres max in UK/Ireland. Nowhere near the 600 litres required. What size would the cylinder have to be for 600 litres?

I'm looking at a nitrogen cylinder supplier that was suggested to me:

Cylinder content 2L at 200 bar

Size 45cm * 10cm

Content 0.42m3

No idea what these figures mean.

Depends on the pressure in the cylinder. To calculate how much gas a cylinder contains you multiply the volume of the cylinder by the pressure in bar. A 30 litre cylinder at 230 bar contains 6900 litres at atmospheric pressure for example.

Do you know what a 2 litre at 200 bar would be?

Going by what frees is stating, a full 2 litre tank at 200 bar of pressure would hold 400 liters of gas (2 litre tank X 200 bar = 400).

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I'm in the US, and people here just get a 20 or 40 cubic foot tank, but here's some additional information on metric sizing if it's helpful:

I linked the May 2018 PPeH on page 24 of this thread. The individual PDF's don't have page numbers on them, but the PDF of section 5 (Hypoxic Death & The Exit Bag) is 42 pages long. If you go to page 29 of 42 in your PDF viewer, it states the following:

"Confusing notation when describing gas cylinders

The size of a compressed gas cylinder is sometimes it's physical volume (i.e. how much water it would hold if filled), and sometimes the volume of compressed gas it can hold. Typical cylinders of nitrogen for a peaceful death are small (2 liters) and hold approximately 400 liters of gas at pressure. These are sometimes referred to as

* either * 2 liter

* or * 400 liter cylinders!

Pressure units used are Bar (bar), Megapascal (MPa), or Pounds per Square Inch (psi).

1 bar = 0.1 MPa = 14 psi"

So basically, the tank is big enough that you could pour 2 liters of water inside of it. It's only able to hold 400 liters of gas because it's filled under very high pressure. For whatever reason, the cylinder size may be described by either its liquid volume or its compressed gas volume.

On the Max Dog site, it seems that the type of regulator, tank connection, and pressure are different for the UK than for the EU, but it has some information about cylinder volume that may translate to whatever options are available to you:

"EU Regulator Kit

Complete with appropriate German DIN 477 fitting. Please note the Gase-Dopp cylinder weighs 4.8 kgm full & has gas at a higher pressure (200 bar/2900 psi) so the 2 litre cylinder contains 400 litres of compressed nitrogen/stickstoff which gives a flow time of almost 30 minutes (at the optimum 15 litres/minute). The Maxx Hund regulator accommodates the higher pressure."