Design of Steel Tanks


The Steel Tanks in simpler words mean vessels made of steel plates. The steel tanks are each located on ground level or are placed on top of towers. The steel tanks which are positioned on ground are backed on a concrete cement base or on the steel grillage groundwork. These steel tanks with perpendicular cylindrical facade and flat base and backed on the ground are known as surface tanks. 

If the steel tanks are positioned on staging or towers, in that case, the steel tanks are called elevated steel tanks. The steel tanks which are situated on top of towers to give the required pressure head. The elevated steel tanks are normally used in association with the pumping stations. The steel tanks are basically used for storage space and supply of water and other essential fluids, like petroleum, diesel, and kerosene.

The steels are designed and manufactured in compliance with code of practice for usage of steels in gravity fluid tanks IS: 805-1981.

The least measure of thickness of steel plates of these tanks have to be 6mm with exception of rooftops. If the steel water tanks have proportions of salt, the thicknesses of these steel plates have to be 1.5mm additional thicker than previous calculation.

Rectangular Steel tanks

The rectangular steel tanks are made of steel plates with level base. The widths of steel plates for the most part embraced are 1.20 m, 1.25 m and 1.30 m relying on accessibility of the plates. The thickness of steel plates ought not be under 6 mm. The base plates are given in the transverse bearing. These plates are turned up at the finishes. These plates and the tee segments are given in the inward side to cover to shape a butt-joint with the side plates of tanks.

Elevated Circular Steel Tank

The elevated circular steel tanks are constructed with hanging base. The circular steel tanks are constructed with hemispherical, segmental and conical bottoms. The hemispherical, segmental or elliptical bases are normally used. The conical bottom is seldom in practice.

It is hard to make-an acceptable association of conelike base with the roundabout brace. The cone shaped base tanks are utilized as a part of railroads . For little tanks, with hemispherical base, the proportion of stature of barrel shaped shell to the width is roughly I: 1. The proportion is l1/4: 1 for the tanks having limit more than 4,50,000 liters. For the curved base tanks, this proportion is 0’6 : I for the tanks under 6,75,000 liters limit and 0.5 : I for tanks of 6,75,()()() liters limit and then some. For the hemispherical base tanks, the hypothetical drop of the base from spring line is one a large portion of the distance across of the ,tank. For the curved base tanks, this drop is one-fourth the breadth, The steel plates utilized for the sides of the tube shaped shell are kept somewhat unique in distances across, so that the courses are put covering each other inside and outside, then again. The shell plates are molded to suit the shape of the tank. The thickness of the plates in the round and hollow shell ought not be under 6 mm. The ostensible plate thickness as prescribed in Seems to be: 805-1981 for the diverse ostensible tank width is embraced as given in Table in IS 805 . The base thickness of plates in the suspended base ought not be not exactly the thickness of plates in the most reduced course of the round and hollow part of the tank. The plates are sheared or planed to an appropriate angle along the edges by caulking.

It is hard to make a proper association of tapered base with the round support. The funnel shaped base tanks are utilized as a part of railroads. For little tanks, with hemispherical base, the proportion of stature of round and hollow shell to the measurement is roughly I: 1. The proportion is l1/4: 1 for the tanks having limit more than 4, 50,000 liters. For the circular base tanks, this proportion is 0’6 : I for the tanks under 6,75,000 liters limit and 0.5 : I for tanks of 6,75,()()() liters limit and that’s only the tip of the iceberg. For the hemispherical base tanks, the hypothetical drop of the base from spring line is one a large portion of the breadth of the ,tank. For the circular base tanks, this drop is one-fourth the measurement, The steel plates utilized for the sides of the round and hollow shell are kept marginally unique in distances across, so that the courses are set covering each other inside and outside, then again. The shell plates are formed to suit the arch of the tank. The thickness of the plates in the tube shaped shell ought not to be less than 6 mm. The ostensible plate thickness as prescribed in IS 805-1981 for the distinctive ostensible tank measurement is embraced as given in Table in IS 805 . The base thickness of plates in the suspended base ought not be not exactly the thickness of plates in the most minimal course of the round and hollow part of the tank. The plates are sheared or planed to a reasonable slope along the edges by caulking.

Pressed Steel Tanks

The pressed steel tanks have come to usage in large degree courtesy  of their easiness in the erection, easiness in transport, set construction, easiness in dismantling assembling and re-erection.

Permissible Stresses

The permissible stresses as provided in IS 800-1984 are considered to be basic stresses