Desalination

Desalination butterfly valve

As the world’s freshwater supplies dwindle and the population increases, desalination plants will experience tremendous growth. Many areas, and not all just arid, are already trying to reduce dependence on groundwater stores. Already, desalination provides fresh water for nearly 400 million people each year, and that number is growing. POV is the world’s valve, actuator, and controls supplier for the desalination market.

There are many methods to desalinate seawater, but the two primary methods are vacuum distillation and reverse osmosis. The latter is the preeminent process, for which POV high performance valves are ideally suited. Typically, cogeneration of power and desalinated water is the most economical option since it takes energy to produce desalinated water.

Desalination plants are typically constructed near or in conjunction with power plants, using excess heat generated by the power plant for the desalination process. Large military vessels, such as aircraft carriers, use nuclear power to desalinate water for crew consumption. Since POV valves are equally ideal for power plant purposes, this creates a win-win situation for the POV customer.

Regardless of the particular process, POV provides the solution. Superior technology and materials of construction make POV the obvious choice for the desalination process. The need for fresh water supplies will continue to grow over the coming years, and POV will grow with it as new products and processes are developed to supply the world with its most precious commodity.







    Desalination is the process of removing salts and other impurities from seawater or brackish water to produce fresh water for drinking, irrigation, and industrial applications. Valves play a critical role in desalination plants, where they are used to control the flow of fluids, regulate pressure, and ensure the safe and efficient operation of the various stages involved in desalination processes.

    There are several types of valves commonly used in desalination plants, each with their unique features, advantages, and limitations:

    Butterfly Valves: Butterfly valve consist of a circular disc that rotates around a central axis to control the flow of fluids or gases. They are often used in low to medium-pressure applications within desalination plants due to their compact design, lightweight, and cost-effective nature. Butterfly valves can be made from various materials, such as stainless steel, ductile iron, or lined with materials like rubber or Teflon to resist corrosion caused by seawater exposure.

    Ball Valves: Ball valve are widely used in desalination plants due to their ability to provide precise flow control and excellent sealing capabilities. They consist of a spherical ball with a hole through the center, which can be rotated to open or block the flow of fluids. Ball valves are suitable for high-pressure applications and can handle a wide range of temperatures. They are available in various materials, such as stainless steel, carbon steel, and exotic alloys, to accommodate different desalination process requirements.

    Gate Valves: Gate valves are commonly used in desalination plants for on-off control of fluid flow in pipelines. They utilize a sliding gate or wedge that moves vertically to open or close the valve. Gate valves are suitable for handling high flow rates and can be made from various materials, including stainless steel, ductile iron, or bronze, to resist corrosion from seawater exposure.

    Globe Valves: Globe valves are used in desalination plants for precise flow control and throttling applications. They consist of a movable disc that comes into contact with a stationary seat, allowing for accurate regulation of fluid flow. Globe valves can handle high pressures and temperatures, but may have a higher pressure drop compared to other valve types, making them less energy-efficient.

    Check Valves: Check valves are essential in desalination plants to prevent backflow and protect pumps and other equipment from damage caused by reverse flow. They allow fluid to flow in one direction only, automatically closing when the flow reverses. Check valves can be found in various designs, including swing check, lift check, and wafer check valves, depending on the specific application requirements.

    Pressure Relief Valves: Pressure relief valves are critical safety components in desalination plants, as they help to maintain desired pressure levels and prevent overpressure situations that could lead to equipment failure or accidents. These valves automatically release excess pressure when it exceeds a predetermined threshold, ensuring the safe and efficient operation of the desalination process.

    When selecting valves for use in desalination plants, it is essential to consider factors such as the operating pressure, temperature, flow rate, and the corrosive nature of seawater. Additionally, the choice of valve material should be compatible with the desalination process's harsh conditions to prevent corrosion and ensure the longevity of the valve. Proper valve selection, installation, and maintenance are critical in ensuring the safe, efficient, and reliable operation of desalination plants.