Freshwater is an undeniable necessity to every human being and industry, but, unfortunately, the most endangered one. But as the freshwater sources like rainwater and glaciers were found insufficient for all, we soon turned to oceans and seas to satisfy our demands.
We lay pipelines to transfer seawater or drill water bores off-shore to extract freshwater from these saline bodies. Let’s explore how various types of throttle valves, piping mechanisms, and designs are adopted in different seawater utilisation systems.
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Extracting fresh water from sea or ocean
According to statistical research, the freshwater available on the earth’s surface suffices only 1% of the human requirements. If we look for alternatives to compensate for the scarcity, the underground water table and the vast expanse of saline water bodies are readily available for use.
Suction pipes to transfer water on the surface.
Saline seawater is directly processed through desalination plants under processes like reverse osmosis, sedimentation, filtration, and various chemical treatments to purify and make it fit for human use.
Large pipes are sent over the water surfaces, floating with the help of pipe/hose floats to send water directly to the inlet of the desalination plant.
Since the pressure is high at the input and RO membranes are delicate to withstand it, different throttle valves are used to control the flow. After refining, the water is again sent through bigger pipes to storage tanks or supplies, where check valves and throttle valves are again used to manipulate the current.
Obtaining from the underground water table
Water from aquifers under the seabed or the land is extracted through bores and pipes. Engineers primarily locate the feasible areas to obtain water safely and begin the extraction projects.
They construct a vertical concrete bore on the land or send the boring equipment on a floating pontoon platform to the middle of the sea to reach the water underground.
Electrically-operated suction pumps and throttle valves with flow control mechanisms are used in the vertical pipes to pull the water up to the storage tanks.
Here, foot valves or shut-off valves like the ball or gate valves and water filters are also essential to check the direction of the water flow and avoid mixing coarse sand and dirt during the suction.
The water is usually fresh, with low salt levels, compared to the seawater, and is directly used after chemical and sanitation treatments. Pipelines are then laid around the cities to supply fresh water to houses and industries.
Water supply for ships and cruise boats
Transporting ferries, recreational cruises, or travelling ships require a constant source of freshwater for regular usage of the travellers on the board and for cooling of the internal mechanical systems. As a ship can’t carry all the supplies beforehand, it uses the surrounding seawater to treat and produce a fresh source for regular usage.
Ships are fitted with suction pumps, desalination systems, and pipelines with various functioning valves to take up the seawater, treat it for purity, and supply fresh water as required. Valves are of utmost importance in these pipes as they help determine the proper amount and flow of the water needed for various purposes.
Throttle valves like gate valves or ball valves are used with the suction pipes when water is taken at high pressure but should be transported to the desalination plants at much lesser pressure.
They are also required in pipes connecting the direct supplying nodes for lessening and regulating the pressure as needed by various equipment. Along with blocking or flow control valves, check valves are also essential to avoid mixing due to a two-way flow.
Water for off-shore oil and gas projects
Oil and gas rigs utilize an array of valves and tangled mesh of pipelines when they set up an off-shore project. Butterfly valves, ball valves, gate valves, or globe valves are prominent in the pipes extracting crude oil from the seabeds and transferring it to the settlement tanks.
Similarly, the setup and equipment sent to the sea (levelling on a floating pontoon or concretely built on pillars in the water) require a constant water supply for working. Water pipes are laid out separately to supply water to the treatment tanks or the HVAC systems for cooling and internal functioning.
Throttle valves are efficiently used here for HVAC systems as pressure drop is required from the condenser to the evaporator while transferring the refrigerants. Here a butterfly valve or the globe valve works the best to adjust according to the equipment specifications.
Conclusion
In the modern world, with the dwindling availability of freshwater, we depend on seas and oceans for an alternate source to suffice our daily and industrial needs.
This article discusses the current scenarios depicting how various water-supplying mechanical systems utilise different pipelines, platform structures, bores, and valves for purifying the saline source to fresh and usable water.
