Green Drain GD35 waterless trap seal for 3.5-inch kitchen floor drains

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GD35

3.5" Waterless Trap Seal

Name: GD35 - 3.5" Waterless Trap Seal
Brand: Green Drain
SKU: GD35
Price: 44.95 USD
Availability: InStock

Fits 3.5" (DN90) drain outlets. Highest flow rate under 4 inches at 323.17 L/min. Drop-in install, no tools required.

$44.95

Free shipping on all US orders

Pipe Size 3.5" (88-95mm)

Flow Rate 323.17 L/min

Install Time 30 Seconds

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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.

Cutaway view of a 3.5-inch floor drain and its trap

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 3.5-inch drains, 88 to 95 mm, and drops in by hand. No tools, no plumber, installed in seconds.

Will it fit? Measure first

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 GD35 seats in a pipe of 88 to 95 mm (3.5 in.). If the opening is oval, use the smaller reading. Outside that range, another size fits: see all sizes.

Drain in section with the grate highlighted: not the part to measure

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.

Drain in section with the bowl highlighted: not the part to measure

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.

Drain in section with the pipe highlighted: the part to measure

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.

Floor drain from above with the grate off: a tape across the pipe opening from A to B — **Measure A to B.** The pipe opening at the bottom of the bowl.

Full installation guide: how to measure, choose a size and install.

Fits these drains

Round floor drain, isometric, with its pipe outlet highlighted — Round

Square floor drain, isometric, with its pipe outlet highlighted — Square

Floor sink, isometric, with its pipe outlet highlighted — Floor sink

Trench drain, isometric, with its pipe outlet highlighted — Trench

Any floor drain whose outlet is a round pipe in the GD35's range. The grate shape does not matter; the pipe under it does. Remove any basket or strainer from the bowl first.

GD35 in section with water flowing down through the open skirt — **Water flowing.** The silicone skirt opens and water passes.

GD35 in section with the skirt closed and sewer gas held below — **Flow stopped.** The skirt closes. Air, odor and insects stay below.

The valve, two states

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.

Step 1: the grate lifted off a floor drain, shown in section

Lift the grate

Most grates lift straight out by hand. Some are held by one center screw; back it out, then lift.

Step 2: measuring the pipe opening at the bottom of the drain, inside wall to inside wall

Measure the opening

Measure the pipe opening at the bottom of the bowl, inside wall to inside wall. The GD35 fits 88 to 95 mm (3.5 in.).

Step 3: the GD35 being pressed down into the pipe opening

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.

Step 4: the grate back in place over the seated GD35

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.

Built for high-volume drainage.

Independently tested performance data. The GD35 delivers 3x the flow capacity of the GD3 at Level U.

323.17 L/min Flow Rate (Level U) 3x the flow capacity of the GD3.

502 Pa Pressure Resistance DTI tested back-pressure rating.

200 Pa Odour Tightness CE/ETA certified gas-tight seal.

>2,500 Cycle Life ASSE 1072 durability tested.

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Technical Specifications

Model	GD35
Pipe Size	3.5" (88-95 mm) / DN90
Height	51 mm
Housing Diameter (no gasket)	78.75 mm (3.100"), bottom 83.6 mm (3.291")
Housing with Gasket	97.46 mm (3.837") wide x 50.82 mm (2.001")
Housing Material	ABS Plastic
Valve Material	Silicone Rubber
Seal Material	Silicone Gasket
Flow Rate	323.17 L/min
Pressure Resistance (DTI)	502 Pa
WaterMark License	WM-022837 (DN90)
Patents	Multiple US & international patents