Davey Supercell Pressure Tank - Captive Diaphragm, Potable Water Rated, 8L to 200L NZ

 A Davey Supercell pressure tank reduces pump cycling, smooths pressure fluctuations, and provides draw-off capacity for your pump system. The tank stores water under pressure using a captive diaphragm design — the diaphragm is held firmly in a central position, allowing the use of a thicker, more reinforced material than bag or bladder tanks for longer service life.

The inner liner is virgin polypropylene (or virgin copolymer polypropylene on the G Series), sealing water from the steel shell. The patented stainless steel water connection seals both the water and air chambers for a leak-free, maintenance-free pressure vessel. Every tank is individually tested before leaving the factory.

Available in three series — Supercell P, Supercell G, and Supercell HP25 — across ten models from 8L to 200L. Select your model from the dropdown.

Certified to NSF Standard 61, WRAS, ACS, ISO 9001, and WaterMark standards. The HP25 series carries WaterMark WMTS-477 (Lic. LN-60075). Manufactured under ISO 9001 quality management and ISO 14001 environmental management systems.

5-year guarantee on all models.

Key specs at a glance

• Diaphragm: Heavy duty butyl rubber — FDA approved for potable water
• Inner liner: Virgin polypropylene (P and HP25 Series) / Virgin copolymer polypropylene (G Series)
• Tank shell: Steel, epoxy primed with 2-part polyurethane enamel
• Water connection: Patented stainless steel — leak-free and maintenance-free
• Sizes: 8L to 200L (10 models)
• Max pressure: 1,000 kPa (standard P Series), 1,600 kPa (PHP16 models), 2,500 kPa (HP25 Series)
• Max water temperature: 90°C (all models)
• Certifications: NSF Standard 61, WRAS, ACS, ISO 9001, WaterMark
• Guarantee: 5 years

Choosing your model

Supercell P Series — standard pressure, 8L to 100L

The standard range for household pump systems. Most models are rated to 1,000 kPa. Two high-pressure variants (PHP16) are rated to 1,600 kPa for systems with higher operating pressures.

Smaller models (8L, 18L, 40L) use a pipe-mount connection. Larger models (60L, 80L, 100L) are free-standing with a 90° stainless steel inlet elbow for horizontal piping.

Supercell G Series — large capacity, condensation-reducing design, 200L

The 24200G uses Davey's patented CAD2 captive diaphragm, which also incorporates a condensation-reducing design to minimise moisture inside the air chamber. Suits large household, farm, or industrial systems where high draw-off capacity is needed. Free-standing with a bottom horizontal inlet.

Supercell HP25 Series — high pressure, 24L and 100L

Rated to 2,500 kPa — the highest pressure rating in the Supercell range. Suited to high-pressure pump systems and demanding applications. Carries WaterMark WMTS-477 (Lic. LN-60075).

Not sure which model or size suits your system? Get in touch and we'll help you choose.

Why Kiwi homeowners choose the Davey Supercell

• Captive diaphragm design allows a thicker, more reinforced diaphragm than bag or bladder tanks
• Virgin polypropylene liner seals water from the steel shell — no water-to-metal contact
• Patented stainless steel water connection — leak-free and maintenance-free for life
• Heavy duty butyl rubber diaphragm with FDA approval — safe for potable water
• Epoxy primed and 2-part polyurethane enamel finish — protected against rust and UV
• CAD2 condensation-reducing design on the G Series
• Every tank individually tested before leaving the factory
• Certified to NSF Standard 61, WRAS, ACS, ISO 9001, and WaterMark standards
• 5-year guarantee

Full technical specifications

Supercell P Series

Supercell G Series

Supercell HP25 Series

Common specs (all models): Steel shell | Epoxy primed, 2-part polyurethane enamel finish | Butyl rubber diaphragm (FDA approved) | Patented stainless steel water connection | Max water temperature 90°C | NSF Standard 61, WRAS, ACS, ISO 9001, WaterMark certified | 5-year guarantee

What's in the box

• 1 × Davey Supercell pressure tank (model per selection)
• Installation documentation

FAQ

What does a pressure tank do?

It stores a volume of water under pressure, giving your pump system a draw-off buffer. When you open a tap, water comes from the tank first — the pump only starts when the tank pressure drops to the cut-in point. This reduces the number of times the pump starts and stops, extends pump life, and smooths pressure fluctuations.

How do I choose the right size?

Larger tanks provide more draw-off capacity — meaning the pump runs less often. For most household pressure systems, an 18L to 60L tank is sufficient. For higher demand or where minimising pump starts is important, a larger tank is worth the step up. Get in touch if you'd like help sizing for your system.

What's the difference between the P, G, and HP25 Series?

The P Series is the standard range covering 8L to 100L, with PHP16 models for higher-pressure systems (up to 1,600 kPa). The G Series offers a single 200L model with the CAD2 condensation-reducing diaphragm design — suited to large installations with high draw-off needs. The HP25 Series is rated to 2,500 kPa — the choice for high-pressure system requirements.

What is the captive diaphragm design?

The diaphragm is held firmly in a central position rather than floating freely. This reduces movement, allowing a thicker, more reinforced diaphragm material than bag or bladder tanks — resulting in longer service life and no creasing or fatigue-points from free movement.

What does NSF Standard 61 certification mean?

NSF Standard 61 certifies that the tank's materials and construction meet safety requirements for products used in contact with drinking water — a recognised standard for potable water applications in NZ and Australia.

Do pipe-mount models attach directly to the pump outlet?

Yes — pipe-mount models connect inline with your pump pipework, typically at the pump outlet or nearby. Free-standing models sit on the floor and connect via the inlet elbow. A licensed plumber should handle the connection to ensure it's correctly integrated with your system.

Can the tank be used for hydronic heating?

Yes — all models are suitable for hydronic heating system expansion tank applications.

What warranty applies?

5-year guarantee on all Supercell models.