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Green Drain GD-MD3 medical device floor drain seal: teal gasket rings and skirt in a white housing, with the model name and a 3 in size banner
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Green Drain™ GD-MD · Medical Device

GD-MD3 Floor Drain Seal

The GD-MD3 fits floor drain pipes with an inside diameter of 68 to 81 mm (3 in nominal). Water drains down through its silicone skirt. When the flow stops, the skirt closes and restricts the upward movement of air and aerosols from the drainage system.

  • 68 to 81 mmFits pipe I.D.
  • 3 inNominal
  • Class IMDR (EU) 2017/745
Inquire about the GD-MD3

GD-MD is the medical version of Green Drain, for hospitals, clinics and care facilities. Ask us for a quote.

Will the GD‑MD3 fit?

Lift the grate and measure the inside diameter of the pipe below it, where the seal will sit. If it measures 68 to 81 mm, the GD-MD3 fits. If not, one of the other sizes will.

ModelFits pipe I.D.Nominal
GD-MD12532 to 38 mm1-1/4 in
GD-MD1539 to 47 mm1-1/2 in
GD-MD251 to 59 mm2 in
GD-MD2555 to 65 mm2-1/2 in
GD-MD27568 to 72 mm2-3/4 in
GD-MD368 to 81 mm3 in
GD-MD3589 to 95 mm3-1/2 in
GD-MD499 to 107 mm4 in
GD-MD5125 to 133 mm5 in
GD-MD6149 to 157 mm6 in

Where two ranges overlap, either size fits. Not sure? Make an inquiry and tell us the measurement.

Common drains it fits

  • GD-MD3 installed in a round floor drainRound floor drain
  • GD-MD3 installed in a square floor drainSquare floor drain
  • GD-MD3 installed in a floor sinkFloor sink
  • GD-MD3 installed in a trench drainTrench drain
  • GD-MD3 installed in a funnel floor drainFunnel floor drain

Not seeing your drain? If its outlet is a round pipe in the GD-MD3's range, it fits. The cover on top does not matter; the pipe under it does.

How to Measure and Install a GD-MD3. Measure first, then install. Jump to either part below the video. The video is in English.

How the GD‑MD works.

A silicone skirt sits inside a rigid housing that seats in the drain pipe below the grate. It works with the P-trap that is already there.

  1. A section drawing of a GD-MD, its silicone skirt open and water falling through it1

    Water flows down.

    The skirt opens under the downward pressure of the water and lets it drain.

  2. The same GD-MD with the flow stopped, the skirt closed across the pipe2

    The flow stops.

    The skirt closes again on its own and forms a physical seal across the pipe.

  3. The same GD-MD closed, with air from the drainage system held below the skirt3

    The drain stays closed.

    The closed skirt restricts the upward movement of air and aerosols from the drainage system. No power, and nothing to operate once it is installed.

>99.9%retention of aerosolised MS2 viral surrogate under controlled laboratory conditions

SGS laboratory testing demonstrated that GD-MD can effectively restrict the upward movement of aerosolised viral-surrogate particles through a drainage opening under the tested conditions.

Independent laboratory evidence supporting passive aerosol-barrier performance: SGS-CSTC, 2025. Tested device performance, not a health outcome. Method and conditions: Technical Summary.

GD‑MD3 specifications.

ModelGD-MD3
Nominal pipe size3 in
Fits pipe inside diameter68 to 81 mm
HousingABS polymer
SkirtSilicone elastomer
Natural rubber latexNone identified
ClassificationClass I medical device, MDR (EU) 2017/745
UDI-DI05745001471118
Basic UDI-DI5745001471GreenDrainMDRJD
ManufacturerGreen Drain Europe ApS, Herning, Denmark (SRN DK-MF-000052289)
Quality systemISO 13485:2016 and ISO 9001:2015
Packed24 to a carton: UDI-DI 15745001471115
Each unit in its own box: UDI-DI 05745001471118

Install it, then inspect it.

Installed by trained facility staff or a technical service provider, following the Instructions for Use. After that, inspect it from time to time for correct position and condition; reinstall it if it has moved, replace it if you see damage or wear. Passive does not mean unmanaged: each step can be recorded, so the drain has its place in the routine of the facility.

  1. A floor drain in a cut-away floor slab with its grate lifted off
    1

    Lift the grate.

    Remove the existing drain grate.

  2. The open drain with the pipe below the grate, where the GD-MD3 will sit
    2

    Check the pipe.

    Make sure the pipe below the grate falls in the size range you chose.

  3. The GD-MD3 being pressed down into the drain pipe
    3

    Press it in.

    Push it into the drain opening and recess it 2 to 4 inches (about 50 to 100 mm) into the pipe, correctly seated and stable.

  4. The grate back on the drain, with the GD-MD3 seated in the pipe below it
    4

    Replace the grate.

    Put the grate back, close it and fit its screws, where the drain has them.

Watch the install for the GD-MD3 It starts at 0:53 in the video above.

What the GD‑MD does, and what it does not.

The device does

  • Function as a one-way mechanical barrier in floor drains
  • Restrict the upward movement of air and aerosols from drainage systems
  • Support hygiene and infection prevention and control programs
  • Reduce environmental exposure pathways associated with floor drains

The device does not

  • Prevent, diagnose, treat, or cure disease
  • Make claims about reduction of infection rates or patient outcomes
  • Replace established hygiene protocols or cleaning procedures
  • Have direct or indirect contact with the human body

Green Drain GD-MD is a passive environmental control device. Use it as one element within a broader hygiene management framework.

The regulatory documents.

The four public documents for Green Drain GD-MD, version 2.0, issued 14 September 2026. Annex II Technical Documentation is held by the manufacturer and provided to competent authorities on request. All EU MDR documents.

EU Declaration of Conformityv2.0 Instructions for Use (IFU)v2.0 Technical Summaryv2.0 Regulatory Summaryv2.0

All GD‑MD sizes.

See every size with its picture on the GD-MD page.

Inquire about the GD-MD3.

Tell us the sizes and quantities you need and where they are going, and we will come back to you.

Make an inquiry
Inquire about the GD-MD3