The dismantling expert refineries and chemical plants trust
Decommissioning is a different discipline from construction. Aged equipment, residual product, fatigued steel and live-site interfaces all change the risk picture. HAIL has invested in dismantling-specific equipment, training and method statements so that one contractor can take responsibility for the entire shutdown — tanks, columns, exchangers, pipe racks, flare stacks and structural steel — under one HSSE plan.
We are the first Indian contractor to apply reverse jacking to an ammonia tank. The same method works on any large-diameter cylindrical tank: lift the shell with hydraulic jacks, cut at ground level, eliminate working-at-height. We currently apply it at Birla Copper Ltd., Dahej for Ostwal Phoschem (India) Ltd., dismantling a double-wall ammonia tank and a 55-metre flare stack.
What we dismantle
Storage tanks
API 650 fuel and chemical tanks, EFR/IFR/DDFR roofs, ammonia and cryogenic tanks, fire-water and DM-water tanks.
Pressure equipment
Reactors, columns, heat exchangers, condensers, boilers, deaerators, drums and ASME pressure vessels.
Flare stacks
Self-supporting and guyed flare stacks up to 60+ metres — engineered cut-down with controlled lowering.
Pipe racks & structures
Refinery pipe racks, equipment platforms, technological structures, silos and industrial buildings.
LPG bullets & spheres
Decommissioning of LPG mounded bullets and spherical vessels — purge, drain and sectional dismantle.
Full plant decommissioning
Aged refinery units, fertiliser and chemical plants — taken from running facility to cleared foundation.
Reverse jacking — the engineering edge
Conventional cutting needs full-tank scaffolding, top-down cutting and weeks of working at height. Reverse jacking lifts the shell on synchronised hydraulic jacks so each ring is cut and lifted off at ground level. Result: ~90% reduction in working-at-height, faster cycle, less scaffolding, and cleaner residue handling. We engineer the jack arrangement to the shell stiffness, residual loads and crane access so that the operation is completely controlled.
How reverse jacking works — step by step
- Aged-plant safety study and HAZOP. Before any crew mobilises, HAIL conducts a structural fitness walk-down and a full HAZOP review of every dismantling step. The output is an approved method statement with a hazard register, mitigation matrix and lift study.
- Isolation, drain-down and gas-freeing. All process connections are positively isolated and blinded. Residual product is drained, the tank is water-flushed, and nitrogen purging cycles are run until gas-free conditions are verified at multiple elevations.
- Roof and appurtenance removal. Roof plates, rafters, pontoon structures (for IFR tanks), manholes, nozzles, ladders, platforms and instrumentation are removed by crane. Open connections are blinded.
- Hydraulic jack installation. Synchronised hydraulic jacks are installed inside the shell perimeter on a prepared base ring. Jack capacity, stroke length and number of stations are engineered to the shell weight, wind load and residual stiffness.
- Lift-cut-lower cycle. The jacks lift the entire shell assembly by one course height. The bottom-most shell ring is now at ground level and is cut using cold-cutting tools (band saw, abrasive saw, hydraulic shears) or plasma after gas-free certification. The cut ring is rigged away by crane and the shell is lowered. This cycle repeats ring by ring from bottom to top.
- Bottom plate and annular ring removal. After all shell courses are removed, the bottom plate is section-cut, loaded and despatched. The annular ring and foundation are cleared or remediated per the agreed handover condition.
- Scrap segregation, transport and documentation. Ferrous scrap, non-ferrous components, insulation and contaminated material are segregated, weighed at a calibrated weighbridge, and transported under manifest with TSDF documentation for hazardous waste.
Types of tanks we dismantle with reverse jacking
| Tank type | Typical diameter | Material challenges |
|---|---|---|
| Crude oil / petroleum tanks | 15 — 80 m | Hydrocarbon sludge, H2S residue, internal floating roof components |
| Ammonia storage tanks | 20 — 35 m | Toxic residue, cryogenic inner shell (LTCS), perlite insulation contamination |
| Chemical storage tanks | 10 — 30 m | Acid residue, rubber-lined or SS-clad internals, corrosion damage |
| LPG bullets and spheres | 3 — 18 m (dia) | Flammable vapour, BLEVE risk during warm-up, thick-wall pressure vessel |
| Water and DM-water tanks | 10 — 50 m | Minimal residue; simpler gas-freeing but often corroded and structurally weakened |
| Cryogenic tanks | 15 — 40 m | Cold-brittle inner shell, vacuum-insulated annular space, controlled warm-up required |
Safety and waste management
- Aged-plant safety study & HAZOP before mobilisation.
- Cold cutting (band saw, abrasive, magnetic drill) in vapour zones; hot work only after gas-free certification.
- Nitrogen purging, scrubber venting and continuous downwind monitoring for hazardous-residue tanks.
- Material segregation: ferrous, non-ferrous, insulation (perlite, foam-glass), refractory and hazardous waste.
- Waste manifests, weighbridge tickets and statutory disposal documentation.
- HSSE-trained workforce with cranes, man lifts, scissor lifts and certified scaffolding.
Reference projects
- Birla Copper Ltd., Dahej (Ongoing) — Reverse-jacking dismantle of double-wall ammonia tank + 55 m flare stack. Zero-incident execution for Ostwal Phoschem (India) Ltd.
- Refinery shutdowns & turnarounds — Multi-discipline support inside live IOCL facilities (Barauni, Gujarat) with full HSSE compliance.
- Plant clearing & equipment salvage — Aged tanks, columns and pipe racks dismantled, segregated and despatched under client manifests.
Equipment we deploy for tank dismantling
- Synchronised hydraulic jacking system — PLC-controlled multi-point jacks matched to shell weight and geometry. Stroke sensors monitor differential lift at each station to prevent shell racking.
- Owned crane fleet — 200 MT, 100 MT, 50 MT and 20 MT crawler and hydraulic cranes for ring removal, appurtenance lowering and scrap handling.
- Cold-cutting tools — band saws, abrasive saws, hydraulic shears and magnetic drills for spark-free cutting in vapour-zone areas.
- Hot-cutting equipment — CNC plasma and oxy-fuel for scrap reduction at lay-down area, used only after written gas-free certification.
- Gas detection and monitoring — multi-gas detectors, ammonia-specific area monitors, LEL monitors and personal gas alarms for continuous in-tank and downwind monitoring.
- Nitrogen banks and scrubber skid — mobile cryogenic nitrogen dewars with vaporiser for inerting, and pre-engineered water/acid scrubber skid for vapour neutralisation during purging operations.
- Access equipment — man lifts, scissor lifts and certified scaffolding for limited elevated work during roof removal and jack installation phases.
Why HAIL for tank dismantling
- India's first reverse-jacking ammonia tank dismantle — documented method, audited HSE.
- Single point of responsibility — engineering, dismantling, transport and disposal under one PO.
- Owned 200 MT, 100 MT, 50 MT and 20 MT cranes — no rental risk on schedule-critical lifts.
- Same workforce that builds tanks; we know exactly how to take them apart.
- Experienced inside live operating refineries (IOCL Barauni, Gujarat) and fertilizer complexes — full PTW integration with plant operations.
- RINA Consulting consortium for independent engineering review on complex dismantling procedures.
Frequently asked questions
What is reverse jacking in tank dismantling?
Hydraulic jacks lift the shell so each ring is cut and removed at ground level — instead of working at 25—30 m height with full external scaffolding.
What kinds of tanks and equipment do you dismantle?
Storage tanks, ammonia and cryogenic tanks, LPG bullets/spheres, columns, reactors, exchangers, boilers, flare stacks, pipe racks and entire plants.
Do you handle hazardous-residue tanks?
Yes — with HAZOP, drain-down, flushing, N— purging, scrubber venting and waste manifesting.
How fast is reverse-jacking dismantle?
Typically 30—40% faster than conventional top-down cutting on a 30 m diameter tank, depending on residue and insulation.
Do you provide aged-plant safety studies?
Yes — independent walk-down, structural fitness assessment, HAZOP and engineered dismantling procedure are issued before mobilisation.