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Green Drain GD3 waterless trap seal for 3-inch commercial floor drains
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GD3

3" Waterless Trap Seal

Fits 3" (68-81 mm) drain outlets. Drop-in install, no tools required.

$42.95

Free shipping on all US orders

Pipe Size 3" (68-81mm)
Flow Rate 105.70 L/min
Install Time 30 Seconds
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Will it fit? Measure the pipe opening under the cover, inside wall to inside wall.

Watch how to measure Size chart
Green Drain measuring keychain with a cutout for each drain size

Measuring keychain $6.95A cutout for every size, so you order the right one.

Size chart

Measure the pipe opening inside wall to inside wall, then find the row your reading falls in. Go by the millimeters: the inch size is only the pipe’s name.

ModelPipe openingSize
GD12532 to 38 mm1.25"
GD1539 to 47 mm1.5"
GD251 to 59 mm2"
GD2555 to 65 mm2.5"
GD3 this page68 to 81 mm3"
GD3589 to 95 mm3.5"
GD499 to 107 mm4"
GD5125 to 133 mm5"
GD6149 to 157 mm6"
International models, by quote
GD3/3577 to 95 mm3 to 3.5"
GD35/489 to 108 mm3.5 to 4"

Full measuring guide
cUPC Listed
ASSE 1072 Compliant
Free US Shipping
SGS Tested: 99.9% Aerosol Retention

For hospitals and clinics: GD-MD, the medical version of this size.

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.

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 GD3 seats in a pipe of 68 to 81 mm (3 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.
How to Measure and Install a GD3. Measure first, then install. Jump to either part below the video.

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

Common drains it fits
GD3 installed in a round floor drain
Round
GD3 installed in a square floor drain
Square
GD3 installed in a floor sink
Floor sink
GD3 installed in a trench drain
Trench
GD3 installed in a funnel floor drain
Funnel

Not seeing your drain? If its outlet is a round pipe in the GD3's range, it fits. The cover on top does not matter; the pipe under it does. Remove any basket or strainer first.

GD3 in section with water flowing down through the open skirt
Water flowing. The silicone skirt opens and water passes.
GD3 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.

1
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.

2
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 GD3 fits 68 to 81 mm (3 in.).

3
Step 3: the GD3 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.

4
Step 4: the grate back in place over the seated GD3

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.

Watch the install for the GD3 It starts at 0:53 in the video above.

SGS tested. The data that matters.

The GD3 was the test model for SGS laboratory testing, which demonstrated that it retained over 99.9% of an aerosolized MS2 bacteriophage, a validated viral surrogate.

105.70 L/min Flow Rate (Level U) No restriction to commercial drainage.
>99.9% Aerosol Retention SGS retained over 99.9% of an aerosolized MS2 viral surrogate.
660 Pa Pressure Resistance DTI tested back-pressure rating.
200 Pa Odour Tightness CE/ETA certified gas-tight seal.
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

ModelGD3
Pipe Size3" (68-81 mm)
Height50 mm
Housing Diameter (no gasket)61.49 mm (2.421"), bottom 66.68 mm (2.625")
Housing with Gasket82.76 mm (3.258") wide x 50.5 mm (1.988")
Housing MaterialABS Plastic
Valve MaterialSilicone Rubber
Seal MaterialSilicone Gasket
Flow Rate105.70 L/min
Pressure Resistance (DTI)660 Pa
SGS Aerosol-Retention Test>99.9% retention of an aerosolized MS2 viral surrogate
WaterMark LicenseWM-022837 (DN80)
PatentsMultiple US & international patents

Industries we serve.

Green Drain is installed across a wide range of facilities.

Healthcare Restaurants & Food Service Schools & Universities Offices & Commercial Hotels & Hospitality Industrial & Manufacturing Food & Beverage Manufacturing Breweries & Wineries Senior Living

Certifications and compliance.

Green Drain cUPC certification - IAPMO File 9301 ASSE 1072-2020

cUPC Listed

IAPMO File 9301

ASSE 1072-2020 Standard

Barrier-type trap seal performance standardEvaluated under IAPMO R&T cUPC File No. 9301

Green Drain CE Mark European Technical Assessment ETA-18/0536

CE / ETA-18/0536

European Technical Assessment

Green Drain NSF/ANSI 2 food equipment certification

NSF/ANSI 2

Food Equipment Certified

Green Drain HACCP International food safety certification

HACCP International

Food safety certification (Certificate RG-05)

Green Drain WaterMark Australia certification WM-022837

WaterMark Australia

WM-022837 (DN80)

Green Drain California Proposition 65 compliant

Prop 65 Compliant

California Material Safety

SGS

SGS Aerosol-Retention Test

Over 99.9% MS2 viral-surrogate retention

Green Drain tested by Danish Technological Institute DTI

DTI Tested

Rapport 957187

Green Drain IAPMO R&T certified plumbing product

IAPMO R&T

Certified Testing Lab

Green Drain VA Godkendelse Danish plumbing approval

VA Godkendelse

Danish Plumbing Approval

View All Certifications

What operators are saying.

"After installing your product in all our floor drains, we could see a noticeable difference in the reduction of fruit fly and mosquito activity. We were also very impressed that the flow rate of our trough drain remained consistent."

Mike Malone, Owner and Head Brewer

Walking Tree Brewery

"I am impressed with the simplistic design and the quality of the materials of construction. Just with the pest issue resolved alone we are sold."

Fred Wilson, Product Specialist

Sysco Central Florida

For architects and engineers.

Write the GD3 into a specification by name. Its spec sheet puts the dimensioned plan and section views, the engineering specification paragraph, performance data and listings on one page. The spec pack adds every model, with the certificates and test reports.

Spec Section 22 13 19
Basis of Design Green Drain GD3, IAPMO File 9301
Patents Multiple US & international patents
Download the GD3 spec sheet Download the full spec pack

PDF. Spec sheet: 1 page. Spec pack: 72 pages, 12 MB. See every model's specifications

The GD3 spec sheet in front of the Green Drain Product Specification Pack

Questions about the GD3.

Will the GD3 fit my 3 inch floor drain?

It fits if the round pipe opening measures 68 to 81 mm (about 2.68 to 3.19 inches) from inside wall to inside wall. The 3 inch size is the name of the pipe, not a measurement, so measure the opening under the grate before you order. The cover on top does not matter; the pipe under it does.

How do I measure my drain for the right Green Drain size?

Lift the grate and find the round pipe opening at the bottom of the bowl. Measure across its center from inside wall to inside wall; do not measure the grate or the bowl, which are wider than the pipe. If the opening is oval, use the smaller reading, and if the reading is outside 68 to 81 mm, find the model that fits in the size chart.

Does the GD3 replace my P-trap?

No. The P-trap stays exactly where it is. The GD3 sits in the drain above the trap and seals with a silicone valve instead of water, so it stays closed when the water in the trap has evaporated.

How do I install the GD3?

Lift the grate, press the GD3 into the pipe by hand until it sits 2 to 4 inches (50 to 100 mm) below the top of the pipe, and put the grate back. The silicone gasket makes a snug seal against the pipe wall. No tools, no plumber, and nothing to wire, prime or top up.

How do I take the GD3 out, and how often should I check it?

It lifts out by hand, or with the Green Drain extraction tool. Inspect the seal around 6 to 12 months in service to confirm the silicone is still intact and sealing properly, and replace only as needed: high-use drains wear sooner, while low-use drains often last a year or longer.

Is shipping free, and can I return the GD3?

Shipping is free on all US orders. Unused, uninstalled products in their original packaging can be returned within 30 days of delivery for a full refund or exchange. Installed or used Green Drains cannot be returned, for hygiene and safety reasons.

Related products.

Green Drain GD2 waterless trap seal for 2-inch floor drains

GD2 (2")

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

GD35 (3.5")

 Green Drain GD4 waterless trap seal for 4-inch floor drains

GD4 (4")
View All Products

Ready to protect your drains?

Drop-in install. No tools. Works from day one.

Add GD3 to Cart Request a Quote