Vertical Pressure Tank | 100L | Solar Expansion

The Bestank-Solar 100L vertical pressure and expansion tank — the largest tank in the Solar Series range, sized for commercial RO installations, large solar hot water systems, and pump installations needing significant pressure-buffer capacity. Steel shell, Italian-made replaceable membrane, vertical format with leg-mounted base.

Why Bestank-Solar Specifically

Bestank is the established mid-market pressure tank brand for the Asia-Pacific region — better-built and longer-lasting than the unbranded commodity tanks, more economical than premium European brands. The Solar Series denotes their high-temperature membrane range, suited for both solar hot water expansion applications and standard cold-water pressure-buffering.

The changeable membrane design is the critical feature: when the bladder eventually fails (typically 7-15 years depending on water chemistry and cycling), you replace only the membrane rather than buying a whole new tank. This shifts the long-term cost equation significantly.

What an Expansion / Pressure Tank Does

A pressure-buffer tank holds water under pressure between the pump and the demand outlets. Two functions:

• Pressure buffering — taps draw from the tank rather than starting the pump for every small demand
• Pump cycle reduction — the pump only engages when the tank pressure drops to cut-in, then stops at cut-out

Without a pressure tank, every tap-opening triggers the pump. Pump cycling like this destroys motors quickly and creates audible nuisance at every tap event. A correctly-sized pressure tank cuts pump starts by 80–95% across the system's life.

Specifications

• Model: BHT-100V-S
• Capacity: 100 litres
• Configuration: vertical with legs
• Maximum working pressure: 10 bar
• Pre-charge pressure (factory): 2 bar
• Diameter: 460 mm
• Height: 990 mm
• Connection: 1-inch
• Original colour: Almond White RAL1013

Membrane

Made in Italy EPDM / BUTYL Solar membrane, rated -20°C to 130°C. High-quality membranes with hygienic certifications approved by European Union and USA institutions. Replaceable design — bladder swap-out without buying a new tank.

Butyl membrane available on request as an option to the standard EPDM/BUTYL composite.

Where This Tank Fits

• Commercial RO installations needing larger pressure-buffer capacity than residential tanks provide
• Large solar hot water systems with significant thermal expansion volume to absorb
• High-flow pump installations where smaller tanks cycle too frequently
• Multi-outlet rural property installations with concurrent demand from many fixtures

For smaller residential RO: use the 12L or 19L versions instead — the 100L is overkill at residential scale.