SP-40 is a 40-liter (10 gallon) expansion vessel designed for closed-loop solar hot water systems. It effectively manages temperature fluctuations to maintain safe pressure levels and protect the system from excessive variations.
Built for extreme environments, the tank supports up to 10 bar (150 psi) and 130°C (266°F). It is factory pre-charged to 3.5 bar (50 psi) with 100% nitrogen gas to ensure stable performance and prevent thermal pressure spikes.
With a 35.5 cm diameter, the SP-40 is ideal for mid-sized solar setups. It supports thermal expansion for water heaters up to 110 gallons, providing a reliable and durable solution for solar applications.
Product Overview
The SP-40 is a 40-liter (10 gallon) diaphragm expansion tank engineered to protect high-capacity solar thermal systems. It effectively manages the expansion of large water-glycol volumes, preventing dangerous pressure spikes during peak sun exposure and maintaining system balance when temperatures drop below freezing.
Built with a heavy-duty cold-rolled steel shell and a Red (RAL 3011) epoxy finish, this tank is designed for maximum durability and rust resistance. The interior features a specialized high-temperature liner and a premium EPDM diaphragm (DIN 4807), ensuring the unit maintains its structural integrity despite the intense thermal loads of commercial solar loops.
The SP-40 comes equipped with a 1" 304 stainless steel connector, offering a lead-free and chemically secure interface. This CE and ISO9001 certified vessel is the professional choice for ensuring the safety and long-term performance of high-volume residential or commercial solar thermal installations
Certification
Specifications and Technical Data
| Parameter | Value |
| Model Number | SP-40 |
| Total Tank Volume | 40 liters / 10 gallons |
| Diameter | 35.5 cm / 14.0 inch |
| Height | 43.2 cm / 17.0 inch |
| Net Weight (NW) | 5.9 kg / 13.0 lbs. |
| Gross Weight (GW) | 6.8 kg / 15.0 lbs. |
| Shipping Volume | 2.12 CUF |
| Operating Temperature | 1 - 130°C / 34 - 266°F |
| Factory Pre-charge | 3.5 bar | 50 psi |
| Max. Operating Pressure | 10 bar | 150 psi |
| Connection | 1” NPT / BSPT Stainless Steel |
| Liner Material | Polypropylene |
| Diaphragm Material | EPDM Rubber |
| Shell | Cold Rolled Carbon Steel |
| External Coating | Triple Grade Blue Paint |
| Pre-charge Gas | 100% Nitrogen |
Key Features & Design Advantages
How the Solar-Plus Pressure Tank Works
In closed-loop solar systems, the heat transfer fluid (often a water/glycol mix) expands significantly as it absorbs intense heat from solar collectors. The SP-40 manages this by storing the expanded fluid against the high-temperature EPDM rubber diaphragm, pushing against the nitrogen-filled air cushion. This safely relieves pressure. When the system cools—such as at night or in freezing temperatures—the nitrogen cushion forces the fluid back into the pipes, preventing the pressure from dropping dangerously low.
Key benefits
Typical Applications
Frequently Asked Question (FAQ)
A: The SP-40 rovides 40 liters (10 gallons) of thermal expansion volume, which is precisely engineered to safely support a 110-gallon solar water heater. It reliably absorbs expanding fluid mixtures (such as water and glycol) from solar installations and evacuated tubes reaching extreme temperatures up to 130°C (266°F).
A: Yes, the SP-40 is 100% manufactured in Taiwan and officially holds both CE and ISO9001 certifications, ensuring premium manufacturing standards.
A : Maintaining a relatively compact footprint for its capacity, the SP-40 has a diameter of 14.0 inches (35.5 cm) and a height of 17.0 inches (43.2 cm).
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.
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