Caverns are cavities created underground in the salt rock by flushing out with water (so-called leaching), which are usually filled with natural gas, crude oil, or air for storage purposes. They serve to compensate for seasonal fluctuations in demand, and supply bottlenecks and optimize the commercial conditions of procurement and thus serve the overall security of supply of the European energy market. In the future, underground storage of regeneratively produced hydrogen will play a greater role.
In addition to the underground facilities, the aboveground facilities include compressors, filters, control stations, measuring facilities, drying facilities, cooling and preheating facilities. On the valve side, control valves play a decisive role in addition to the various shut-off and safety valves.
Since the natural gas in the salt caverns is usually injected and discharged again via the same pipeline, the control valves in these pipes play a special role. They should regulate the quantity when the natural gas is pressed into the cavern and the discharging quantity when it is withdrawn with a constant pressure change gradient. Ensure largely pressure-loss-free operation in the fully open state (with similar pressure ratios between the cavern and the network pipeline). Avoid overshooting and pressure shocks. Cover a wide flow range, which brings conventional control valves to their performance limits.
Of the total of 75 operated caverns in the East Frisian municipality of Etzel (Friedeburg), 51 are used to store natural gas.
For 4 of these caverns, which have already been in operation for years, a high-pressure control valve specialist the manufacturer TEC artec GmbH from Oranienburg near Berlin, has supplied control ball valves in the last two years.