Storage tank

The storage tank is a fluid storage building used to hold large quantities of a single fluid in a connected fluid network. It is commonly used in oil and chemical setups to accumulate raw materials and excess products, providing buffering so refineries and chemical plants can continue operating without interruption. The tank participates in the same fluid segment as the pipes it is connected to, so its contents always share the same fill percentage and fluid type as that segment; multiple tanks on the same segment always have identical fill states.

Because the fluid segment is considered uniform, a storage tank acts as an even-volume buffer regardless of where inflows or outflows occur along that segment. This behavior allows a tank to smooth throughput for high-volume recipes such as acid neutralisation and steam condensation, preventing machines from becoming full or empty during fluctuating input rates. The tank can be connected to the circuit network to broadcast the amount of its contained fluid as a signal, enabling automated control and alerts based on fluid levels.

Fluids in a storage tank can be removed by draining with a pump, by flushing the tank or the entire fluid system in the GUI, or by mining the tank. Draining with pumps moves the fluid out without destruction. Flushing or certain actions (mining and not directing the contents) will destroy the fluid. When a storage tank is mined while its fluid matches that of other nearby tanks, its contents are transferred into the next nearest matching storage tanks rather than being lost.

Storage tanks also serve as practical energy storage when filled with steam. A tank filled with high-temperature heat-exchanger steam (500°C) stores approximately 2.425 GJ of energy; filled with boiler steam (165°C) it stores approximately 750 MJ. This makes tanks a viable replacement or supplement for accumulators in steam-based power systems: fill tanks with steam during periods of low consumption (for example when solar is producing) and draw them down during peak demand (such as at night or when turrets fire).

Practical notes and usage considerations:

• A single storage tank capacity: 25,000 units of fluid. Tanks on the same pipe segment always show the same percentage full.
• Use tanks as short-term buffers on high-throughput lines to stabilize inputs to refineries and chemical plants.
• Connect tanks to the circuit network to read fluid type and amount for automated process control or safety shutdowns.
• For steam-based energy buffering: one tank of 500°C steam can keep a single steam turbine running at full rated output for roughly 417 seconds; one tank of 165°C steam can keep a single steam engine running for roughly 833 seconds.
• When reorganising or removing parts of a network, be mindful that mining or flushing can destroy fluids unless properly drained; use pumps to preserve contents when needed.
• Multiple tanks on the same segment do not increase diversity of stored fluids — the segment can only contain one fluid at a time, and all connected tanks will contain that same fluid.