Stacks that rise to the height the norms demand

Not panel by panel in the air. The column is fabricated on the ground in two or three sections, each one complete with its bracing, platform steel and the exhaust riser already fitted up the centre. A mobile crane then tails each section up and lands it on the splices. Working at height is reduced to bolting the splice joints and the final alignment.

A 1500 × 1500 mm four-leg lattice. Legs step from ISA 150 × 150 × 15 at the base to ISA 110 × 110 × 12 above roughly 18 m, spliced in about 6 m lengths, with ISA 65 × 65 × 8 bracing throughout. A typical 30 m column works out near 10.4 tonnes before platforms and handrail.

For a 30 m column, an isolated raft around 5000 × 5000 × 700 mm with 700 × 700 pedestals and 300 × 600 tie beams, cast on a PCC blinding. Final sizes are always confirmed against the soil report and the wind zone — the numbers above are what these columns have typically needed, not a substitute for design.

Yes. The pipe — sized to suit the DG set, with insulation and aluminium cladding — runs up the centre of the lattice, guided off the legs at intervals. It is installed during ground fabrication so it stands up with the steel, rather than being threaded through afterwards.

By the CPCB/MoEF rule for the set rating, not by preference — which is why the height is a compliance input to the structure, not an afterthought. Our stack height calculator works it out for a given kVA, and the structure is then engineered to whatever that height demands.

Access platforms with grating and handrail, a caged ladder the full height, aviation obstruction lamp, lightning arrestor, bird mesh at the outlet, a pollution check point for sampling, and an ash collection point at the base of the riser.

Because the engine does. Generator sets from about 1000 kVA upwards run V-configuration engines with two turbochargers — so two exhaust lines leave the set, each through its own silencer. After the silencers a fabricated Y-joint merges them into one common pipe, and that single run continues to the stack riser. The common pipe is sized to the rating — 14 inch at 1000 kVA rising to 18 inch at 2000 kVA, in MS B-class ERW — and the whole run is insulated and aluminium-clad for heat protection.

No — and this is a different question from one set’s two banks meeting in a Y, which is standard. Manifolding separate sets into a common exhaust lets condensate and exhaust gas migrate into whichever engine is standing idle, with no failsafe once they are joined. Each set gets its own riser. Where a site regulation forces a single chimney, it becomes an engineered special: per-set condensate drains, duct entries angled into the stack, minimum spacing between nozzles, and the stack bore sized for every set running at once.

Four details, all standard on our stacks: a rain cap and bird mesh at the outlet, horizontal pipe runs sloped away from the engine, a condensate drain after the silencer, and thermal-expansion bellows anchored so pipework forces never reach the turbocharger. During erection, every open engine and pipe end stays blanked until the exhaust system is complete — rainwater in a stopped engine is how hydrolock and seized turbos happen.