Section
2.5" Waterless Trap Seal
Fits 2.5" (64-72 mm / DN65) drain outlets. Drop-in install, no tools required.
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Inspect the seal around 6 to 12 months in service to confirm the silicone is still intact and sealing properly. Replace only as needed: high-use drains wear sooner, while low-use drains often last a year or longer.
How it works.
Green Drain is a one-way valve for your floor drain. Water flows down and out. Nothing comes back up.
Inside sits a soft silicone valve. Running water pushes it open; the moment the water stops, it closes and seals tight against sewer gas, odors, and pests. Because it seals with silicone instead of water, it never dries out the way an ordinary trap can, even when the drain goes weeks without use.
It fits 2.5-inch drains, 64 to 72 mm, and drops in by hand. No tools, no plumber, installed in seconds.
Measure the pipe. Not the grate, not the bowl.
Lift the grate. At the bottom of the drain body is a round pipe opening. Measured across its center from inside wall to inside wall, that is the only number that matters. The GD25 seats in a pipe of 64 to 72 mm (2.5 in.). If the opening is oval, use the smaller reading. Outside that range, another size fits: see all sizes.
Don't measure the grate
The grate is the cover you walk on. It sits on top of the drain body and is wider than the pipe underneath, so its width tells you nothing about fit.
Don't measure the bowl
The bowl is the basin under the grate that funnels water down. It is wider than the pipe too. The Green Drain does not sit here.
Measure the pipe
At the bottom of the bowl is the round pipe opening. This is where the Green Drain seats, so this is the width to measure. Wipe it clean, then measure inside wall to inside wall.
Full installation guide: how to measure, choose a size and install.
Any floor drain whose outlet is a round pipe in the GD25's range. The grate shape does not matter; the pipe under it does. Remove any basket or strainer from the bowl first.
One-way. Opens for water going down, closes when the flow stops. No water to top up, no power, nothing to prime.
Inspect the seal around 6 to 12 months in service and replace only as needed.
Installs in 30 seconds. No tools.
Lift the grate
Most grates lift straight out by hand. Some are held by one center screw; back it out, then lift.
Measure the opening
Measure the pipe opening at the bottom of the bowl, inside wall to inside wall. The GD25 fits 64 to 72 mm (2.5 in.).
Press it in
Push the Green Drain into the pipe by hand until it sits 2 to 4 inches (50 to 100 mm) below the top of the pipe. The silicone gasket creates a snug seal against the pipe walls.
Replace the grate
Put the grate back. Done. Nothing to wire, prime or top up, and a full commercial floor takes an afternoon. Lifts out by hand, or with the extraction tool.
Specify Green Drain in your next project.
Download the Revit family set for every Green Drain model, and find us listed in BSD SpecLink and MasterSpec.
Technical Specifications
| Model | GD25 |
| Pipe Size | 2.5" (64-72 mm) / DN65 |
| Height | ~35 mm |
| Housing Material | ABS Plastic |
| Valve Material | Silicone Rubber |
| Seal Material | Silicone Gasket |
| Flow Rate | 72.50 L/min |
| WaterMark License | WM-022837 |
| Patents | Multiple US & international patents |
Industries we serve.
Green Drain is installed across a wide range of facilities.
Certifications and compliance.
WaterMark Australia
WM-022837
ASSE 1072-2020 Standard
Barrier-type trap seal performance standardEvaluated under IAPMO R&T cUPC File No. 9301
HACCP International
Food safety certification (Certificate RG-05)
NSF/ANSI 2
Food Equipment Certified
SGS Aerosol-Retention Test
Retained over 99.9% of an aerosolized MS2 bacteriophage viral surrogate
DTI Test Report
Danish Technological Institute, Report 957187
Ready to protect your drains?
Drop-in install. No tools. Works from day one.