What are the types of gas storage tanks?

A gas storage tank refers to specialized machinery used for storing gas. Gas storage tanks are commonly used to store and transport gas. Depending on the tank's pressure resistance, they can be divided into high-pressure gas storage tanks and low-pressure gas storage tanks; depending on the metal material used, they can be divided into stainless steel plate gas storage tanks, carbon steel stainless steel plate gas storage tanks, and alloy stainless steel plate gas storage tanks.

In urban heating supply projects, tanks are used to store natural gas. The function of the vessel is similar to that of a gas storage tank, and it is also used in industries such as crude oil, chemical industry, and metallurgy. According to the supply pressure, they are divided into low-pressure and high-pressure categories; the former is further divided into wet and dry types based on structure.

Wet gas storage tank

Below is a stainless steel water tank, with multiple adjustable sleeve-type tower sections welded from thick steel plates at the top. The tower sections adjust according to changes in gas storage and supply volume. An exhaust valve is installed in the middle of the tower section to ensure connection and sealing between tower sections. There are two adjustment methods for the tower sections: positioning pin type and spiral guide rail type. The positioning pin type gas storage tank has a positioning pin frame composed of positioning pins, cross strong shafts, and ring beams around the kitchen sink, providing very high bending stiffness. Guide wheels assembled at the top of the tower section slide left and right along the positioning pins (see Figure 1). The spiral guide rail type gas storage tank has spiral sliding rails welded at a 45° slope on the surface of the tower section, allowing the guide wheels at the top of each tower section to rotate along the rails for adjustment.

The stainless steel water tank can be made from thick steel plates or prefabricated components or cast-in-place prefabricated concrete structures. Because of the heavy weight of the water inside the stainless steel water tank, when built on poor foundations, pile foundations can be used to prevent excessive foundation settlement, or the stainless steel water tank can be designed in a ring shape to reduce water flow. Additionally, the stainless steel water tank can be constructed underground, which can reduce settlement and decrease the overall height-to-width ratio of the tank.

Dry gas storage tank

The tank body is a vertically welded steel plate cylinder, internally equipped with a piston that stores gas below it. The piston adjusts according to the amount of gas stored and supplied. Sealing structures are installed around the piston to prevent gas leakage. Heavy weights are placed on top of the piston to provide the required gas supply pressure. The sealing methods for dry gas storage tanks include hydraulic oil sealing, vegetable oil sealing, and flexible diaphragm sealing.

1. Hydraulic oil sealed gas storage tank. The cross-section of the cylinder and piston is polygonal. The polygonal top is equipped with I-shaped vertical rods. The wall panels, cast-in-place slabs, and piston bottom plates are made of 5-6mm thick steel plates formed into grooved prefabricated components, providing certain tensile strength and bending stiffness. The top of the piston is arranged in a radial truss structure, with guide wheels on both sides. When the piston adjusts, the guide wheels slide along the vertical rods. The tank exterior has a ring-shaped walkway every 15 meters in height. The sealing structure consists of an oil cup outside the piston and a double rocker; the oil cup is filled with mineral oil to seal the gas below the piston.

2. Vegetable oil sealed gas storage tank. The cross-section of the cylinder section is annular. I-beam vertical rods are set at intervals on the outside of the cylinder wall, and multiple ring-shaped walkways are arranged along the full height to enhance the bending stiffness of the thick-walled cylinder. The piston is spherical. A truss structure is set near the top outside of the piston, with a guide wheel on each side that slides left and right along the inner side of the cylinder wall as the piston adjusts. The truss structure and guide wheels also prevent the piston from tilting during operation. The sealing structure of the gas storage tank consists of a sealing ring and clamping device made from fabric and plastic layers. Lubricating grease is introduced between the sealing ring and the tank wall to improve sealing performance and reduce sliding friction.

3. Flexible diaphragm sealed gas storage tank. The appearance is cylindrical, similar to an oil storage tank. The tank contains a spherical piston. A flexible diaphragm is installed around the piston, with the other end connected to the inner side of the tank wall. This creates a sealed space below the piston; as the piston adjusts, the flexible diaphragm rolls up and down accordingly. A sleeve-type protective fence made of spiral corrugated plates is installed around the top of the piston to prevent deformation of the diaphragm's sides. The tank is equipped with a balancer to automatically correct piston tilt.

High-pressure gas storage tank

The tank body is welded from high-quality high-strength steel into a cylindrical or spherical shape. Spherical tanks use less steel and have uniform stress distribution. However, manufacturing, assembling, and welding spherical tanks are more difficult than cylindrical tanks, so they are generally used only in places with very high supply pressure. The ends of cylindrical tanks use elliptical or hemispherical heads. When using standard elliptical heads, to ensure the stainless steel head has the same compressive strength as the tank body, the elliptical length-to-axis ratio can be 2:1.