Cascade heating. Gas tanks.

The market of equipment today can propose 2 types of underground gas tanks: horizontal and vertical. Horizontal cisterns are used in Southern and other regions where the temperature in winter never exceeds the limit of -20ºС (gas tank stops to evaporate gas at temperatures ≤ -20ºС).

To operate in more extreme weather conditions there was developed vertical cistern to store liquefied petroleum gas (LPG; GPL). Vertical gas tank from «Antonio Merloni Cylinders Ghergo Group S.p.А.» keeps its working capacity at air temperature up to -40ºС. In fact it «hides» at a depth using free of charge thermal potential of the earth to heat gas (ground temperature at the bottom of gas tank is +6 … +8ºС).

On base of gas tanks and gas pipeline installed to the socle of the house on the object it is possible to organize: gas supply without electricity (independent gasification) and hot water supply without electricity.

Designed service life of «Antonio Merloni» gas tank is about 50 years. It is possible thanks to the wall thickness of the gas tank made of 10 mm low-alloyed sheet steel. Upper and lower bowls of the cistern are forced out by heavy presses; they have thickness of 20 mm.

Let’s observe more carefully a necktube of one of two cascade connected gas tanks. What’s going on inside?

Double reduction is provided by high pressure reducing gear box and low pressure reducing gear box. Gas tank is equipped by charging valve, liquid fraction valve and manometer which shows pressure inside the gas tank. When pressure exceeds 17,5 bars safety valve is activated – gas discharges to the atmosphere. At heat (if anyone decides to do harm) thermo-key shrivels and blocks gas supply. Under the «hat» of the gas tank there are also situated two level detectors (0 … 50 % и 50 … 97 %).

The cistern is connected to three component anode-cathode protection which protects gas tank under the ground and connected to protective bad «Marsupio». This bag covers all surface of the gas tank and guards the cistern from mechanical damages during ground movements. A hatch («hat») made of stainless steel is hermetically closed thanks to sealing ring made of cellular rubber substance. There is also non-return valve which provides ventilation.

Connecting cisterns by cascade as it’s shown in this video (neighbourship of two gas tanks «hats») gives reserve – big reliability and required volume.