The ROT-4 is a standard 18L (4.5-gallon) steel water storage tank for reverse osmosis systems, ensuring safe, pressurized water delivery.
It is designed for a maximum of 7 bar (100 psi) and 90 °C (194 °F). Factory pre-charged with 100% nitrogen to 0.5-0.7 bar (7-10 psi), it offers stable performance despite temperature changes.
Measuring 28.0 cm (11.0 in) in diameter and 34.6 cm (13.6 in) in height, this stand-model tank includes a plastic base for easy installation in under-sink or commercial settings.
Product Overview
The ROT-4 is an 18-liter (4.5 gallon) diaphragm pressure tank engineered as a standard Reverse Osmosis (RO) drinking tank. Designed to process 18 liters per hour, it is ideal for households of up to 4 people and common office environments. It securely stores purified water and delivers it with controlled, robust pressure.
Perfect for residential and commercial use, the ROT-4 features a hygienic internal design that prevents water from contacting the steel tank shell. Utilizing an FDA-approved polypropylene liner and a DIN 4807-compliant butyl rubber diaphragm, it ensures safe operation and fresh, tasteless water free of odors.
Manufactured with premium steel materials and holding top-tier certifications including NSF58, CE, and IAPMO, Aquasky RO tanks are produced in ISO 9001:2008 registered facilities to deliver a long service life, dependable performance, and the safest drinking-water compatibility on the market.
Certification
Specifications and Technical Data
| Parameter | Value |
| Model Number | ROT-4 |
| Total Tank Volume | 18 liters / 4.5 gallons |
| Diameter | 28.0 cm / 11.0 inch |
| Height | 34.6 cm / 13.6 inch |
| Net Weight (NW) | 3.4 kg / 7.5 lbs. |
| Gross Weight (GW) | 3.8 kg / 8.4 lbs. |
| Shipping Volume | 1.08 CUF |
| Operating Temperature | 90°C / 194°F |
| Factory Pre-charge | 0.5 - 0.7 bar | 7 - 10 psi |
| Max. Operating Pressure | 7 bar | 100 psi |
| Connection | 1/4” NPT Stainless Steel |
| Liner Material | Polypropylene (FDA grade) |
| Diaphragm Material | Butyl Rubber (DIN 4807 compliant) |
| Shell | Cold Rolled Carbon Steel |
| External Coating | Triple Coated Liquid Paint |
| Pre-charge Gas | 100% Nitrogen |
Key Features & Design Advantages
How the RO-PLUS Pressure Tank Works
ROT-4 stores supplemental water securely between the butyl rubber diaphragm and the polypropylene liner, while the nitrogen-filled air chamber maintains constant system pressure. When a drinking tap or coffee maker is activated, the compressed nitrogen pushes the purified water into the system at a controlled pressure.
This specialized design ensures stable performance, completely separates the water from the metal shell, and maintains a clean water zone that is completely free of rubber or plastic odors.
Key benefits
Typical Applications
Frequently Asked Question (FAQ)
Yes, the ROT-4 holds 18 liters (4.5 gallons) and supports 18 liters per hour. It is an excellent, widely used standard tank for small offices and standard households consisting of about 4 people.
No. The ROT-4 is designed to be entirely maintenance-free during its service life. We utilize a specialized brass cap with an internal O-ring that guarantees no air loss from the air-vent.
Additionally, it is the only RO storage tank in the industry pre-charged with 100% Nitrogen, which naturally resists permeation and prevents pressure fluctuations caused by temperature changes.
AQUASKY invented the leak-safe technology applied to the stainless connector 18 years ago, setting the benchmark for drinking water tanks. Manufactured in an ISO 9001:2008 registered facility and holding top-tier certifications like NSF58 and CE, it is recognized as one of the safest pressure vessels in the market.
Customized Colors & Packaging
We offer a wide range of customization options to match your exact needs - from custom colors to branded packaging and logo design.
Watch our video to explore the possibilities and see how we help your products stand out in the market.
Downloads & Certification Links
Detailed product information and data
Collection of all relevant certifications.