Green Drain GD125 waterless trap seal for 1.25-inch drains

Main

Side

Top

Inside

Parts

GD125

1.25" Waterless Trap Seal

Name: GD125 - 1.25" Waterless Trap Seal
Brand: Green Drain
SKU: GD125

Fits 1.25" (32-38 mm) drain outlets. Drop-in install, no tools required.

€31,95

Excl. VAT. Ships from our EU warehouse in Denmark.

Pipe Size 1.25" (32-38mm)

Flow Rate 29.22 L/min

Install Time 30 Seconds

Request a Quote Contact our EMEA team

For hospitals and clinics: GD-MD, the medical version of this size. Class I medical device under MDR (EU) 2017/745.

cUPC Listed

ASSE 1072 Compliant

Ships from Denmark

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 1.25-inch drain and its trap

How it works.

Green Drain is a one-way valve for your 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 1.25-inch drains and drops in by hand. No tools, no plumber, installed in seconds.

Will it fit? Measure first

Measure the pipe. Not the strainer, not the flange.

Lift the strainer. Under it is a round pipe opening. Measured across its center from inside wall to inside wall, that is the only number that matters. The GD125 seats in a pipe of 32 to 38 mm (1.25 in.). If the opening is oval, use the smaller reading. Outside that range, another size fits: see all sizes.

Sink drain in section with the strainer highlighted: not the part to measure

Don't measure the strainer

The strainer is the perforated disc in the bottom of the sink. It sits on top of the drain and is wider than the pipe underneath, so its width tells you nothing about fit.

Sink drain in section with the flange highlighted: not the part to measure

Don't measure the flange

The flange is the rim around the drain hole that the strainer sits in. It is wider than the pipe too. The Green Drain does not sit here.

Sink drain in section with the pipe highlighted: the part to measure

Measure the pipe

Under the flange 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.

Sink drain from above with the strainer off: a tape across the pipe opening from A to B — **Measure A to B.** The pipe opening under the strainer.

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

Common drains it fits

GD125 installed in a hand-sink drain — Hand sink

GD125 installed in a kitchen sink — Kitchen sink

GD125 installed in a laundry tub — Laundry tub

Not seeing your drain? If its outlet is a round pipe in the GD125's range, it fits. The cover on top does not matter; the pipe under it does. Remove any basket or strainer first.

GD125 in section with water flowing down through the open skirt — **Water flowing.** The silicone skirt opens and water passes.

GD125 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 strainer lifted out of a sink drain, shown in section

Lift the strainer

Most strainers 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 under the strainer, inside wall to inside wall. The GD125 fits 32 to 38 mm (1.25 in.).

Step 3: the GD125 being pressed down into the pipe opening

Press gently to seat

Recess 2 to 4 inches below the pipe top. The silicone gasket creates a snug seal against the pipe walls.

Step 4: the strainer back in place over the seated GD125

Replace the strainer

Put the strainer back. Done. Fully sealed in under a minute.

For Architects & Engineers

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.

Download Revit Families View full specifications →

Technical Specifications

Model	GD125
Pipe Size	1.25" (32-38 mm)
Height	27 mm
Housing Diameter (no gasket)	30.27 mm (1.192")
Housing with Gasket	40.22 mm (1.583") wide x 27.45 mm (1.081")
Housing Material	ABS Plastic
Valve Material	Silicone Rubber
Seal Material	Silicone Gasket
Flow Rate	29.22 L/min
WaterMark License	WM-022837 (DN32)
Patents	Multiple US & international patents