iSpring T32M 4-Gallon Pressurized RO Water Storage Tank, White — 3.2 Gal Usable, 1/4" Stainless Valve

The iSpring T32M is a compact, pressurized 4-gallon water storage tank built for reverse osmosis systems, delivering odorless, food-grade water with an included 1/4" tank valve.

If you run a household or under-sink reverse osmosis (RO) system, the T32M tank stores purified water under pressure so it’s ready at the tap. This metal-bodied tank uses a food-safe butyl diaphragm and a controlled manufacturing process so the stored water stays neutral in taste and smell. Pre-pressurized for typical residential plumbing and supplied with a stainless steel 1/4" valve, the T32M installs easily and is compatible with most RO setups.

How much water does this tank actually hold and how is capacity measured?

The T32M is rated as a 4-gallon tank but provides approximately 3.2 gallons of usable water under normal operating pressure because part of the shell volume is occupied by the air bladder. That usable volume is what you’ll draw from the tap between refills.

• Metal shell with internal butyl diaphragm creates the water chamber
• Approximately 3.2 gallons usable capacity under typical conditions
• Pre-pressurized to 7–10 psi to match residential RO systems

What materials and safety standards does the T32M use to protect water quality?

The tank’s inner bladder is made from food-grade butyl rubber and undergoes a post-curing procedure to reduce taste and odor. Independent third-party testing confirms the materials meet recognized NSF/ANSI criteria for contact with drinking water.

• Food-grade butyl diaphragm for neutral taste and odor control
• Post-cure manufacturing step to stabilize the bladder material
• Third-party testing to validate compliance with NSF/ANSI standards

How does the included valve and connections simplify installation?

The T32M arrives with a stainless steel 1/4" NPT tank valve so you can hook it directly to standard RO tubing without sourcing extra fittings. The valve’s stainless construction resists corrosion and the tank’s outlet fits common RO system layouts for both vertical and horizontal placement.

• Stainless steel 1/4" NPT valve thread for reliable connections
• 1/4" tank valve included — no separate adapter needed
• Designed to discharge efficiently in either vertical or horizontal orientation

Will this tank perform reliably in a typical home plumbing setup?

Yes. The T32M is pre-pressurized between 7 and 10 psi to match most reverse osmosis systems and household lines, so it starts working out of the box. Its metal shell and tested diaphragm provide long-term, low-maintenance storage for filtered water.

• Factory pre-charge saves initial setup steps
• Durable metal construction for long service life
• Works with common residential RO flow rates and fittings

Who is this for: The iSpring T32M is suited for homeowners, apartment dwellers, and anyone using an under-sink reverse osmosis system who needs a compact, reliable storage tank. It’s a good choice when you want food-safe materials, a pre-pressurized unit that installs quickly, and a stainless 1/4" valve included so you can connect the tank to your RO lines with minimal additional hardware.