Price range: $40.00 through $60.00

Coupler Flange for the 2″, 3″, and 4″ Series Watertight Enclosures. These flanges allow you to combine multiple tubes for greater internal length. Not compatible with the first generation non-locking tubes.

If you’re looking for a complete underwater enclosure, check out the Watertight Enclosure Configuration page. Simply add an additional tube and this coupler flange to your configured enclosure for a complete kit.

U.S. customers will be charged a tariff surcharge of $4.80 - $7.20 for this product. Learn more
SKU: COUPLER-FLANGE-VP Category:
HS Code: 7616.99.5190
Country of Origin: China

Product Description

Have you ever needed a longer watertight enclosure? Use the Coupler Flange to connect any two Watertight Enclosure tubes of the same diameter together. You can mix acrylic and aluminum tubes, different lengths, or chain multiple tubes using additional Coupler Flanges.

The Coupler Flange is basically the standard flange with the sealing interface mirrored on both sides. It has the same features: made of anodized aluminum, dual radial O-rings for reliable high-pressure sealing, PTFE locking cords, anti-rotation feature, and internal RAILS mounting points.

They’re simple to use, just attach a tube at either end and assemble the rest of your enclosure as normal. The Coupler Flange doesn’t affect the depth rating of your tubes, just keep in mind the lowest-rated component sets the depth rating for the whole assembly, and very long builds should use external support.

Tubes and coupler flange with the locking cords installed.

Product Description

Have you ever needed a longer watertight enclosure? Use the Coupler Flange to connect any two Watertight Enclosure tubes of the same diameter together. You can mix acrylic and aluminum tubes, different lengths, or chain multiple tubes using additional Coupler Flanges.

The Coupler Flange is basically the standard flange with the sealing interface mirrored on both sides. It has the same features: made of anodized aluminum, dual radial O-rings for reliable high-pressure sealing, PTFE locking cords, anti-rotation feature, and internal RAILS mounting points.

They’re simple to use, just attach a tube at either end and assemble the rest of your enclosure as normal. The Coupler Flange doesn’t affect the depth rating of your tubes, just keep in mind the lowest-rated component sets the depth rating for the whole assembly, and very long builds should use external support.

Tubes and coupler flange with the locking cords installed.
CAD model is of the 4″ Coupler Flange.

Specifications

 Drawing
Series DiameterRadial Seal O-ringFlange OD (E)Piston Diameter (F)Piston Length (G)Overall Length (H)Inner Mounting Hole Circle (J)WeightPart Number
50 mm (2")-031
Buna-N 70A
58.0 ± 0.1 mm50.95 ± 0.05 mm15.5 ± 0.1 mm43 ± 0.1 mm43.0 ± 0.1 mm60 gBR-106247
75 mm (3")-150
Buna-N 70A
88.9 ± 0.1 mm79.95 ± 0.05 mm19.1 ± 0.1 mm54 ± 0.1 mm68.6 ± 0.1 mm138 gBR-106256
100 mm (4")-154
Buna-N 70A
114.3 ± 0.1 mm103.95 ± 0.05 mm19.1 ± 0.1 mm54 ± 0.1 mm94.0 ± 0.1 mm189 gBR-106257
Material: Aluminum 6061-T6, type III anodized for all flanges
Locking Cord Diameter (D): 2.6 ± 0.4 mm for all flange sizes
Inner Mounting Holes (I): M3x0.5 for all flange sizes

3D Models

WTE2-COUPLER_FLANGE (.zip)

WTE3-COUPLER_FLANGE (.zip)

WTE4-COUPLER_FLANGE (.zip)

Revision History

March 31 2026

  • BR-106247, 50 mm (2") – Initial release
  • BR-106256, 75 mm (3") – Initial release
  • BR-106257, 100 mm (4") – Initial release

See the Using Coupler Flanges section of the Watertight Enclosure guide:

Watertight Enclosure (WTE) User Guide
Learn how to assemble and use a Watertight Enclosure!

Support

Blue Robotics Technical Support Form

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