APT-300 Diaphragm Pressure Tank

300-Liter (81 Gallon) Pressure Tank for High-Flow Booster Water Systems Aquasky PumPlus Series | Made in Taiwan

APT-300 is designed for hotels, schools, and public facilities, provide strong, stable water pressure and reduces pump cycling.

 

APT-300 has a total volume of 300 liters (81 gallons). The tank is designed for a maximum operating pressure of 10 bar (150 psi) and a maximum operating temperature of 90 °C (194 °F). It is factory pre-charged to 3.1 bar (45 psi) for stable system performance.

 

With a diameter of 55.0 cm and a height of 146.1 cm, the weight 39.9 kg design makes installation quick and convenient while saving space.

APT-300 Liter 300 / Gal 81

Product Overview

The APT-300 is a 300-liter (81-gallon) diaphragm pressure tank designed for high-flow residential, public, and light commercial booster pump systems. It stabilizes water pressure and reduces pump cycling.

APT-300 is ideal for regions with unstable or fluctuating municipal water pressure, widely used in homes and buildings where booster pumps are required. Its hygienic internal design, separate water from compressed gas and prevent water contact direct with the tank shell, ensures safe operation for cold sanitary water circuits, pressurized systems, and water storage applications.

Manufactured with premium materials and certified by NSF, CE, WaterMark, IAPMO, and other international bodies, APT-300 complies with global standards including those in the United States, Europe, Australia, and Asia. Produced in ISO-certified facilities, Aquasky pressure tanks delivers long service life, dependable performance, and safe drinking-water compatibility.

Certification

Specifications and Technical Data

Parameter Value
Model Number APT-300
Total Tank Volume 300 liters / 81 gallons
Diameter 55.0 cm / 21.7 inch
Height 146.1 cm / 57.5 inch
Net Weight (NW) 39.9 kg / 88.0 lbs.
Gross Weight (GW) 45.9 kg / 101.2 lbs.
Shipping Volume 15.91 CUF
Operating Temperature 1 - 90°C / 34 - 194°F
Factory Pre-charge 3.1 bar | 45 psi
Max. Operating Pressure 10 bar | 150 psi
Connection 1” NPT / BSPT Stainless Steel
Liner Material Polypropylene
Diaphragm Material Butyl Rubber
Shell Cold Rolled Carbon Steel
External Coating Triple Grade Blue Paint
Pre-charge Gas 100% Nitrogen

Key Features & Design Advantages

  • Carbon steel shell construction
  • Triple-layer polyurethane & epoxy-coated exterior for rust protection
  • Stainless-steel water connection with patented leak-safe technology
  • High-performance variable-geometry butyl rubber diaphragm
  • Internal virgin FDA-approved polypropylene liner
  • Patented leakage-free O-ring sealed air valve cap 
  • 100% factory pre-charged with nitrogen (not regular air)
  • Reinforced wall bracket for inline models; engineered thermoplastic pump stand and replaceable tank base for vertical and horizontal models
  • High level of customization
  • 100% made in Taiwan
Materials & Design Advantages

How the Pumplus Pressure Tank Works

APT-300 stores supplemental water between the butyl rubber diaphragm and the polypropylene liner, while the nitrogen-filled air chamber maintains constant system pressure. When water demand occurs, the compressed nitrogen pushes water into the system at a controlled pressure.

This design ensures stable performance and supports reliable operation for showers, faucets, dishwashers, washing machines, and other fixtures.
 

Key benefits

  • Stabilizes water pressure for dependable flow
  • Reduces frequent pump starts and minimizes motor cycling
  • Extends pump lifespan and helps improve system reliability
  • Improves energy efficiency and reduces power consumption
  • Long service life with no routine maintenance

Typical Applications

  • High-flow residential booster pump systems
  • Apartment buildings and villas
  • Guest houses and small hotels
  • Small commercial and public facilities
  • Drinking-water pressure systems
  • Water usage demand up to 94 L/min

Frequently Asked Question (FAQ)

Q1 : Is APT-300 sufficient for a hotel or school building? How do I choose between APT-300 and APT-325?

A: Yes. A 300-liter (81-gallon) tank is generally sufficient for most hotel or school building. The APT-300 can support up to 94 L/min water usage, provides stable water pressure, and can reduce booster pump start/stop frequency by over 60%. 

If your building has higher water demand, long piping distance, or frequent simultaneous water usage → choose APT-325 for higher flow stability.

Quick guide:
APT-300: Hotels, schools, water usage ≤94 L/min

Q2 : Can I install the APT-300 myself (DIY)?

A: We strongly recommend having the APT-300 installed by a qualified plumber or technician for the following reasons:

Safety & Proper Setup: The APT-300 is a pressure vessel, and correct installation is critical. A professional will ensure:
• The pre-charge pressure is set correctly (typically 2 PSI below the system cut-in pressure).
• All pipe connections are properly sealed and leak-free.
• The installation location can safely support the unit's weight.

System Compatibility: The tank must be correctly integrated with your booster pump, pressure switch, and piping system to ensure stable performance and avoid operational issues.

Warranty Protection: Installation by a non-professional may affect your product warranty coverage.
A professional technician can typically complete the installation, testing, and calibration within 2–3 hours.

Q3 : Does the APT-300 require regular maintenance? How long should it be replaced?

A: The APT-300 is designed to be “maintenance-free”.

  • No regular maintenance required.
  • No filter elements or consumables need replacement.
  • No air recharging needed during normal use (we use 100% Nitrogen pre-charge, which won't leak like air).

Simply check the pre-charge pressure once every 1–2 years using a standard tire pressure gauge. If the pressure is low, you can refill the Nitrogen by yourself or ask a plumber to do it.

Service Life: Under normal operating conditions (water temperature ≤ 99°C, pressure ≤ 10 bar), APT-300 designed to last over 10 years. Many of our customers have used it for over 15 years with normal operation.

Warranty: We offer a 3-year factory warranty covering manufacturing defects and material flaws. 

Installation Tip: Ask your plumber to measure your water pressure during installation and recommend the most suitable system configuration.
 

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

PUMPLUS Pressure Tank Blue
Certification Link

Collection of all relevant product certifications.

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