Reverse Osmosis (RO) filter systems have revolutionized water purification by removing contaminants at the molecular level, thereby providing high-quality drinking water. However, RO filtration is a slow process and cannot deliver immediate high-flow water like standard filtration methods. Without a storage tank, an RO system would require several minutes to fill just a single glass of water. Relying solely on direct filtration would be impractical for everyday use. To address this issue, RO filter systems employ a pressure storage tank that accumulates purified water, keeping it under a moderate pressure, sufficient to make it ready for immediate and convenient dispensing. These tanks have become an essential component of RO systems in residential, commercial, and industrial settings.
Historical Development of RO Storage Tanks
The development of RO storage tanks traces back to the mid-20th century when RO technology was first adopted for desalination and water purification. Initially, RO systems required direct water flow, limiting their efficiency. The introduction of pressurized storage tanks in the 1970s provided a breakthrough in system design, making RO filtration practical for households and commercial settings. Over time, advancements in materials and manufacturing techniques have enhanced tank durability, safety, and functionality.
How Pressure Storage Tanks Work
The core function of an RO storage tank is to store purified water while maintaining adequate pressure for dispensing. Here’s a breakdown of how these tanks operate:
Water Inflow and Filtration
o The RO system slowly purifies water through a semipermeable membrane, removing contaminants like heavy metals, chlorine, and bacteria.
o The purified water is then directed into the storage tank for accumulation.
Internal structure and Pressurization
o Most RO storage tanks have a dual-chamber design: one for water and another for pressurized air or a bladder.
o When water enters the tank, it compresses the air or bladder, building pressure within the tank.
o This pressure allows water to flow out efficiently when the faucet is opened, negating the need for additional pumping mechanisms in small systems.
Water Dispensing and Replenishment
o When the faucet is opened, the compressed air in the tank forces water out, delivering it at a consistent pressure.
o As water exits, the pressure inside the tank decreases, signaling the RO system to resume filtration, refilling the tank until full.
>Types of RO Storage Tanks and Materials Used in RO Tanks
There are different types of RO storage tanks available, each with specific benefits:
• Plastic Storage Tanks: These are common in home RO systems and are lightweight and cost-effective. The butyl or rubber bladder used in these pressurized tanks, ensures that water remains uncontaminated while being stored.
• Steel Tanks with Bladder Liners: These tanks have a pressurized bladder inside a metal casing, preventing contamination and improving durability. Stainless steel is often used in high-end tanks due to its corrosion resistance and durability.
• Composite Tanks: Made from a combination of materials like fiberglass and polyethylene, these tanks provide strength to withstand high pressures and are corrosion-resistance, making them suitable for larger industrial applications.
Benefits of Pressure Storage Tanks
RO filter system pressure storage tanks offer several advantages that enhance the efficiency and usability of RO filtration systems:
• Consistent Water Supply: Instead of waiting for water to pass through the filter, a storage tank provides instant access to purified water.
• Improved Water Pressure: Without a storage tank, water flow from an RO system can be slow due to the low processing speed of the membrane. The tank provides pressurized water for better flow rates.
• Enhanced System Longevity: RO membranes function optimally when they operate in longer cycles, filling a tank with each cycle, rather than through frequent on-and-off cycles that would result from turning the system on and off every time the faucet is opened. Storage tanks reduce the frequency of these cycles, thus improving the system's lifespan. By reducing the frequency of start-stop cycles, the tank helps the RO system last longer.
Best Practices for Using an RO Storage Tank
To maximize the efficiency and longevity of RO storage tanks, consider the following recommendations:
• Regular Maintenance: Clean and sanitize the tank every six months to prevent bacterial growth and contamination. Chlorine bleach can be added to the tank and allowed to sit for one hour. Then, flush the tank by running the system to fill it and opening the faucet to completely drain it. Repeat this process for two or three cycles. Do not add bleach to the RO system before the membrane, as chlorine can damage the sensitive RO membrane.
• Monitor Air Pressure: Check the air pressure inside bladder tanks to ensure proper function. If water flow slows significantly, check for leaks or incorrect pressure settings. Over-pressurizing can cause reduced water storage capacity and affect water flow rate. Typically, the tank should have about 5 psi of pressure in the bladder when the tank is empty of water.
• Optimal Placement: Ensure the tank is installed in a cool, shaded area to prevent material degradation due to heat exposure.
Whether for home or business use, a pressure storage tank enhances convenience and functionality and is an essential component of any RO filtration system.
