Pressurizers

A tube network runs at low pressure on its own. Each carrier a station sends holds up to {carrier_size_unpressured} items, and the station has a {carrier_ticks} tick delay before sending the next.

A Pressurizer anywhere on the network raises it to high pressure while it has fuel. Carriers then send {carrier_size_pressured}, and stations send them with a {carrier_pressured_ticks} tick delay. Autotubes are not affected by pressure.

Right-click it to add coal or charcoal; hoppers can feed it too. Valid fuel items provide 128 high pressure carriers each. Tubes can connect to it on any side but its front.

The teletype's catalogue tooltip shows whether its network is at high or low pressure.
