Design Of Pressed Steel Water Tank Pdf 12
Design Of Pressed Steel Water Tank Pdf 12
Pressed steel water tanks are a type of water storage tanks that are made of steel plates that are pressed into shape and bolted together. They are used for storing potable water, fire protection water, irrigation water, and industrial water. Pressed steel water tanks can be designed in various shapes and sizes, depending on the site conditions and the water demand. In this article, we will discuss some of the design aspects of pressed steel water tanks, such as the capacity, the configuration, the appurtenances, the cathodic protection, the coating systems, and the construction considerations.
The capacity of a pressed steel water tank depends on the water demand and the available space. The water demand can be estimated by considering the peak demand, the fire flow, the top and bottom capacity levels, the water quality issues, the energy costs, and the future needs. The available space can be determined by conducting a soil investigation and considering the environmental impact. The capacity of a pressed steel water tank can range from a few cubic meters to thousands of cubic meters.
Design Of Pressed Steel Water Tank Pdf 12
The configuration of a pressed steel water tank can be either ground-supported or elevated. Ground-supported tanks can be either reservoirs or standpipes. Reservoirs are tanks that have a low height-to-diameter ratio and are usually located at ground level or below ground level. Standpipes are tanks that have a high height-to-diameter ratio and are usually located above ground level. Both reservoirs and standpipes can have various roof designs, such as flat, conical, dome, or umbrella. Elevated tanks are tanks that are supported by columns or pedestals above ground level. Elevated tanks can have multiple-column or single-column supports. Multiple-column elevated tanks have several columns that support a steel tank on top. Single-column elevated tanks have one column that supports a steel tank on top. The column can be either concrete or steel.
Appurtenances are the accessories that are attached to the pressed steel water tank to facilitate its operation and maintenance. Some of the common appurtenances are shell manholes, pipe connections, overflow pipes, ladders and safety devices, roof openings, vents, devices for indicating water level, and emergency fill/withdraw connections. Shell manholes are openings on the tank shell that allow access to the interior of the tank. Pipe connections are openings on the tank shell that allow inlet and outlet pipes to connect to the tank. Overflow pipes are pipes that discharge excess water from the tank to prevent overfilling. Ladders and safety devices are structures that allow climbing to and from the tank roof and provide protection from falling. Roof openings are openings on the tank roof that allow access to the interior of the tank. Vents are openings on the tank roof that allow air to enter and exit the tank to prevent vacuum or pressure buildup. Devices for indicating water level are instruments that show the amount of water in the tank. Emergency fill/withdraw connections are openings on the tank shell that allow filling or draining of the tank in case of an emergency.
Cathodic protection is a method of preventing corrosion of metal surfaces by making them act as cathodes in an electrochemical cell. Corrosion is a process where metal atoms lose electrons and become ions that dissolve in water or form compounds with other elements. Cathodic protection works by supplying electrons to the metal surface from an external source, such as a sacrificial anode or an impressed current system. A sacrificial anode is a metal that has a lower electrochemical potential than the metal to be protected and corrodes instead of it. An impressed current system is a device that applies an electric current to the metal surface from an external power source. Cathodic protection can be applied to both interior and exterior surfaces of pressed steel water tanks to extend their service life.
Coating systems are layers of materials that are applied to metal surfaces to provide protection from corrosion, abrasion, ultraviolet radiation, chemical attack, and biological growth. Coating systems can be classified into interior coatings and exterior coatings. Interior coatings are coatings that are applied to the interior surfaces of pressed steel water tanks to prevent corrosion and contamination of the stored water. Interior coatings can be either liquid-applied or powder-applied. Liquid-applied coatings are coatings that are applied by spraying, brushing, rolling, or dipping. Powder-applied coatings are coatings that are applied by electrostatic spraying or fluidized bed dipping. Exterior coatings are coatings that are applied to the exterior surfaces of pressed steel water tanks to prevent corrosion and enhance the appearance of the tank. Exterior coatings can be either organic or inorganic. Organic coatings are coatings that are based on carbon-containing compounds, such as paints, enamels, lacquers, and epoxy resins. Inorganic coatings are coatings that are based on metal-containing compounds, such as zinc, aluminum, and ceramic.
Construction considerations are the factors that affect the design, fabrication, erection, and inspection of pressed steel water tanks. Some of the construction considerations are the design standards, the contract documents, the constructor capabilities, the guarantees, the soil investigations, the foundations, the tank site, the tank coating, the tank water testing and disinfection, and the engineers role. Design standards are the specifications that define the minimum requirements for the design of pressed steel water tanks. Some of the design standards that are commonly used are ANSI/AWWA D100, Standard for Welded Carbon Steel Tanks for Water Storage; ANSI/AWWA D102, Standard for Coating Steel Water-Storage Tanks; and ANSI/AWWA D103, Standard for Factory-Coated Bolted Carbon Steel Tanks for Water Storage. Contract documents are the documents that describe the scope, terms, and conditions of the contract between the owner and the constructor. Contract documents include the drawings, specifications, bid forms, agreements, bonds, and addenda. Constructor capabilities are the skills, experience, and resources of the constructor that affect the quality and cost of the construction project. Constructor capabilities include the fabrication facilities, the erection equipment, the personnel qualifications, and the quality control procedures. Guarantees are the promises made by the constructor to the owner regarding the performance and durability of the pressed steel water tank. Guarantees include the warranty period, the liability limit, and the remedy options. Soil investigations are the studies conducted to determine the physical and chemical properties of the soil at the tank site. Soil investigations include the soil sampling, testing, and analysis. Foundations are the structures that support the weight and stability of the pressed steel water tank. Foundations can be either shallow or deep. Shallow foundations are foundations that are placed near the surface of the soil and transfer the load to the soil by bearing. Deep foundations are foundations that are placed below the surface of the soil and transfer the load to the soil by friction or end bearing. Tank site is the location where the pressed steel water tank is erected. Tank site includes the site preparation, the site access, the site security, and the site utilities. Tank coating is the process of applying coating systems to the interior and exterior surfaces of the pressed steel water tank. Tank coating includes the surface preparation, the coating application, the coating inspection, and the coating repair. Tank water testing and disinfection is the process of verifying the structural integrity and sanitary condition of the pressed steel water tank. Tank water testing and disinfection includes the hydrostatic testing, the leakage testing, and the chlorination. Engineers role is the function of the engineer in overseeing and supervising the construction project. Engineers role includes the design review, the shop drawing review, the construction observation, and the final acceptance.
Pressed steel water tanks are a type of water storage tanks that are made of steel plates that are pressed into shape and bolted together. They have various design aspects that need to be considered, such as the capacity, the configuration, the appurtenances, the cathodic protection, the coating systems, and the construction considerations. By following the design standards and contract documents, and by collaborating with qualified constructors and engineers, pressed steel water tanks can be designed and constructed to meet the water storage needs of various applications.
: AWWA (American Water Works Association). 2019. M42 Steel Water-Storage Tanks. Denver: AWWA.
: AWWA (American Water Works Association). 2023. ANSI/AWWA D100-23 Standard for Welded Carbon Steel Tanks for Water Storage. Denver: AWWA.