Valves and pressure regulators

The tank holds 8000 kPa of oxygen. Only a few kPa of it may enter the room at a time. Between the two sits no tap but a regulator – and for emergencies a valve that shuts everything off.

The digital valve#

The digital valve (StructureDigitalValve) is a shut-off with a data port. It has no Open – you open it through On:

sbn VALVE HASH("Absperrung") On 1    # open
sbn VALVE HASH("Absperrung") On 0    # closed

When open it equalises both sides, in both directions. It does not pump, it only lets through where there is a pressure difference.

The pressure regulator#

The pressure regulator (StructurePressureRegulator) pushes gas from input to output until the pressure from Setting is reached on the output side – or until the input is empty. It is the classic pressure reducer: behind a high-pressure tank it holds a supply network at a fixed pressure.

sbn REGULATOR HASH("Versorgung") Setting 200   # network at 200 kPa
sbn REGULATOR HASH("Versorgung") On 1

The back pressure regulator#

The back pressure regulator (StructureBackPressureRegulator) looks at the other side: it only opens once the pressure from Setting is reached on the input side, and then lets the excess through. It is a relief valve: if a network rises above its value, it blows off.

Both regulators need power, 100 W, and switch with On. The digital valve gets by with 5 W.

Setting goes up to 60,795 kPa on both, from the factory they are at 50 kPa. And unlike the digital valve the regulators push like a small pump: every tick they move at least 101.325 kPa in 10 litres, even against higher pressure on the other side. So a pressure regulator fills its network even when the tank in front of it already has less pressure – until the inlet is empty.