The chief purpose of most tanks and dams is for water storage for use in a variety of applications.

There is thus a requirement to access to the water for immediate or future use. Also in the case of decorative water features there is a need to filter and purify the water.

Geo- line has thus developed a range of flanges and connectors for sealing pipes to liners and for use in many applications dependant on specific requirements.


Geo-line’s tank connectors are manufactured with a BSP (British Standard Pipe) thread which is suitable for most SA applications.

The connectors are available in a various sizes, ranging from 15mm to 75mm diameter.

The connectors are manufactured from a UV stabilised virgin polypropylene. The connectors are easy to install. In the case of a dam liner being used, an opening is cut into the liner to the same dimensions as the connector, which is then pushed through and locked into place by way of the nut ring. There are no additional sealing agents required as the connector is designed to offer a water-tight seal. Any standard pipe can then be attached to the connector by way of the threaded opening.

There is no steel or elements susceptable to corrosion used making the connection long-lasting and durable while preventing harmful materials from accessing the water.


In many larger tanks and dams there is a requirement for larger pipes and pipe fittings.

Geo-line offers a range of specialty bolted fixed flanges (FFD) as well as bolted threaded flanges (FFE)

Our fixed flanges range in size from 50mm to a large 250mm

Our threaded flanges range from 50mm to 110mm

The flanges are manufactured from uPVC (unplasticised polyvinyl chloride) which is a rigid, chemically resistant form of PVC and can thus be glued onto any standard uPVC pipe using a general uPVC solvent.

All of our flanges are supplied standard in conjunction with our custom made uPVC bolts.

The bolts are welded into the flanges to prevent water seepage by way of the bolt threads and therefore it is not necessary to hold the bolt head when tightening.
A gasket is also provided sealing the liner to the flange with 100% efficacy.

Finally a loose flange (FLD) is then placed atop the gasket and liner to further mechanically seal theseal the flange. This is done by using our custom nylon nuts, making the complete system 100% hermetically sealed.

These non- corrosive elements all combine to create a non-corrosive long-lasting seal.

If there is a requirement to run a pipe further from point of penetration, another fixed flange can be used rather then a loose flange allowing the connection of a further pipe within the dam.


When building a koi pond or such related decorative water feature there is a general requirement for a bottom drain. A bottom drain is a means of attracting surplus bottom muck, sludge and fish waste that accumulates on the bottom of the pond.
Geo-line’s bottom drains are designed to adhese easily onto a standard uPVC pipe and to seal then to the liner as per the standard Geo-line flanges. The bottom drain is then fitted with a closed flange top.


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