35–180 L Stainless Steel Fuel Tank – RINA/CE Standard, High Durability

Stainless steel fuel tanks (capacities from 35 L up to 180 L) provide maximum strength and longevity on board – they are ideal when reliability is paramount (e.g., long-range cruising or professional use). Constructed from marine-grade AISI 316 stainless steel, these tanks boast exceptional corrosion resistance, even in saltwater environments, and will not rust. This ensures your fuel remains clean, free of metal contamination, and that the tank itself will maintain its integrity for many years. RINA and CE certifications confirm that the tanks meet all European safety standards – the walls, welds, and fittings have been tested for impact resistance, pressure stability, and high-temperature performance.

Each stainless tank is equipped with a broad inspection hatch on top, which serves as a multifunctional module. This hatch includes: a large fill opening with a cap (facilitating direct refueling or access for inspection/cleaning), an integrated fuel vent for vapor ventilation (to safely relieve pressure and fumes during filling and use), and the primary fuel outlet – a 90° elbow fitting with 3/8" female thread for connecting the fuel line to your engine. The tanks are factory-prepared for diesel systems as well – they feature a second pre-threaded opening (usually sealed with a metal plug) that can be easily opened to screw in an additional fitting for a fuel return line, which is especially important for diesel engines. This makes the tanks versatile for both gasoline and diesel installations.

Additionally, on the top plate of the tank, a 5-hole flange is provided, allowing you to mount a fuel level sending unit. You can choose to install either a mechanical gauge (float with dial) or an electronic sender to hook up to a dashboard gauge – the tank is compatible with both types. For larger volumes (above ~100 L), internal baffles are integrated inside the tank, which help reduce fuel sloshing and movement during rough seas, preserving the boat’s stability and protecting the structure from undue stress.

• 35–63 L tanks: Compact stainless steel vessels suitable for smaller craft (4–6 m) or as auxiliary/reserve tanks on mid-sized boats. Their small-to-medium capacity is excellent for short outings or for boats with limited installation space. The stainless construction ensures that even small amounts of fuel can be stored over time without risk of contamination.
• 67–112 L tanks: Mid-range capacity tanks, well-suited for most powerboats (6–8 m) and sailing yachts where a reliable fuel supply is needed for day-long or overnight trips. These capacities allow for longer distances to be covered and are popular for boats with single engines ~150–250 HP. Their design facilitates installation in engine bays or below decks with minimal modifications.
• 144–180 L tanks: Large stainless tanks, recommended for bigger yachts and cruisers (8+ m) or vessels with twin high-consumption engines. A capacity of 150–180 L provides for very extended cruising without refueling – a crucial factor for offshore passages or commercial applications (e.g., fishing boats, patrol craft). Even at this large capacity, the steel walls withstand thermal stress and potential fire exposure better than plastic alternatives, adding a layer of safety.

Stainless steel offers the advantage of an extremely high melting point and non-flammability – in the event of a machinery space fire, a steel tank is more resilient and less likely to contribute to the fire compared to a plastic tank. Moreover, the AISI 316 material is certified for fuel contact, meaning it will not leach impurities or react with gasoline, diesel, or biofuels. These tanks come ready for installation; it is recommended to secure them firmly with appropriate straps and to ground them according to requirements (stainless steel facilitates grounding to dissipate static electricity). With Five Marine’s stainless steel tanks, you receive a premium solution – a combination of durability, safety, and functionality that will serve reliably throughout your boat’s lifetime.