Glass-fused-to-steel (GLS) tanks have become the default choice for large water and wastewater storage in many projects across Egypt and the region. Here is what they are, when they make sense, and what separates a good erection job from a bad one.
What is a GLS tank?
A GLS tank is built from steel panels coated on both faces with a layer of glass that is fused to the steel at high temperature. The glass gives the corrosion resistance and a smooth, hygienic surface; the steel gives the strength. The panels are bolted together on site with sealant at every joint, on top of a concrete foundation.
Where GLS tanks fit best
- Potable water storage for cities, factories and compounds
- Fire-fighting water reserves
- Raw water and treated water in water treatment plants
- Industrial effluent and wastewater (equalisation, sludge, digesters)
Compared with a reinforced-concrete tank, a GLS tank goes up much faster, needs no curing time, and can be dismantled and relocated. Compared with a site-welded steel tank, it needs no on-site painting and has a far longer maintenance-free life.
What erection really involves
Most GLS tanks are erected from the top down using a jacking system: the roof and top ring are assembled at ground level, lifted, and each lower ring is bolted in underneath. That keeps the crew working at ground level and avoids heavy cranes. The critical points are the foundation level, panel handling (a chipped coating is a future corrosion point), correct sealant application at every joint, bolt torque, and a hydrostatic test before handover.
At El Safa we erected two GLS tanks of about 1,400 m³ each, 16 m high, for the water treatment plant at the Lesaffre Egypt factory in New Nubaria, working with Veolia Water Technologies, with a full inspection and test plan behind every stage.
Supply, erection, inspection and repair
We supply GLS tanks through our manufacturer agencies, and we erect tanks whoever made them. We also inspect and repair existing GLS tanks: damaged panels, leaking joints and corrosion around fittings. And because we manufacture our own lifting jacks, we can mobilise quickly without waiting for equipment.
See our bolted water tanks service or send us your tank size and site location for a technical offer.