Industry Detail
Chemicals & Petrochemicals
Corrosion-resistant refractories and insulation for reactors and crackers.
Refractory & Insulation for Chemicals & Petrochemicals
Petrochemical and chemical processing plants combine high-temperature fired equipment with long runs of heat-traced and insulated pipework, and both are governed by a safety case as much as by an efficiency one. Fired heaters, reformers, crackers, and thermal oxidisers need refractory linings that hold up under continuous operation and cyclic upset conditions. Around them, hundreds of metres of process piping must be insulated to maintain product temperature, protect personnel from contact burns, and control the pipe wall temperatures at which corrosion under insulation develops. That last point is the defining insulation problem in this sector: CUI is a documented cause of loss of containment, and it is driven by insulation and cladding detailing rather than by thickness. Zenco Systems supplies refractory castables and bricks for fired equipment, ceramic fibre for hot linings, calcium silicate and rockwool for process pipework, and the gaskets, packings, and fire sealants used across chemical plants in Kenya and East Africa.
Solutions We Supply
Refractory & Insulation Selection by Equipment Type
| Zone / Equipment | Service Conditions | Recommended Materials |
|---|---|---|
| Fired heaters & reformer furnaces | 900–1400°C, continuous duty, flame impingement risk | Refractory castable, high alumina refractory castable, ceramic fibre blanket |
| Thermal oxidisers & incinerators | 1000–1500°C, aggressive combustion products, cycling | High alumina refractory castable, high alumina refractory brick |
| Reactor & vessel external insulation | 200–600°C, large surface area, personnel protection | Rockwool insulation board, calcium silicate board, high temperature insulation board |
| Hot process piping | 150–500°C, load-bearing at supports, heat loss control | Calcium silicate board, rockwool insulation, thermal insulation roll |
| CUI-susceptible piping | 60–150°C, moisture ingress, corrosion risk under insulation | Aluminum foil insulation blanket, aluminum foil tape, rockwool insulation |
| Flanges, valves & penetrations | Sealing, fire stopping, thermal movement | Graphite packing, high temperature gasket, fire sealant S160, ceramic fibre blanket |
Common Failure Modes in Chemicals & Petrochemicals
Corrosion under insulation as a containment risk
Water held against carbon steel beneath insulation corrodes the pipe wall invisibly, and in petrochemical service the consequence of eventual failure is loss of containment rather than merely lost heat. The 60–150°C band is the most aggressive, and the controlling factors are vapour barrier integrity and cladding detail rather than insulation thickness.
Refractory failure in fired heaters during upsets
Fired heaters and reformers are designed for steady operation, but trips, flame impingement, and rapid cooldowns impose thermal shock the lining was not optimised for. Damage accumulates through upset events rather than during normal running, which makes lining condition difficult to predict from operating hours alone.
Personnel protection on hot surfaces
Any accessible surface above roughly 60°C is a contact burn hazard, and in a plant with extensive hot pipework this becomes a substantial insulation scope in its own right. It is driven by a safety requirement rather than an energy calculation, and the two do not always specify the same thickness.
Turnaround scope certainty
Petrochemical turnarounds are planned years ahead and costed to the day. Refractory or insulation scope discovered once equipment is opened is disproportionately expensive to address inside the window, which puts a premium on inspection and material pre-positioning ahead of the shutdown.
How to Specify the Right Material
Split the problem into fired equipment and pipework. For fired heaters, reformers, and thermal oxidisers, use refractory castable rated to 1600°C for general duty and high alumina castable to 1750°C where flame impingement or higher process temperatures apply, with ceramic fibre blanket as backup and for lower-load hot face positions. For pipework, the specification driver is the temperature band. Above about 150°C the question is heat loss and personnel protection, and calcium silicate board is preferred at supports and load-bearing positions with rockwool over the general run. Between roughly 60°C and 150°C the specification must be written against corrosion under insulation — aluminium foil faced insulation with fully sealed laps and a continuous vapour barrier, with cladding detailed to shed water. Fire sealant and graphite packing cover penetrations, flanges, and valve sealing where both thermal and fire performance are required.
Installation & Maintenance Notes
- Treat vapour barrier continuity as the primary control for corrosion under insulation — seal every lap and penetration with aluminum foil tape rather than relying on cladding alone.
- Detail cladding to shed water at all horizontal runs, flanges, and valve boxes; these are the points where CUI reliably starts.
- Use load-bearing insulation such as calcium silicate at pipe supports so the insulation is not crushed into a thermal bridge and a moisture trap.
- Inspect fired heater refractory after any significant trip or upset, not only on the turnaround calendar — thermal shock damage accumulates through events rather than running hours.
- Pre-position refractory and insulation materials before a turnaround opens; scope discovered mid-window is disproportionately expensive to resolve.
Materials Used in Chemicals & Petrochemicals
Chemicals & Petrochemicals Refractory & Insulation FAQs
What is corrosion under insulation and why does it matter here?
CUI is corrosion of the pipe or vessel wall caused by water held against the steel beneath insulation. It matters more in petrochemical service than elsewhere because the eventual consequence is loss of containment, not just lost heat. It is most aggressive between roughly 60°C and 150°C, and it is controlled by vapour barrier integrity and cladding detail rather than by insulation thickness.
How do you specify insulation to prevent CUI?
With a continuous vapour barrier, every lap and penetration sealed, cladding detailed to shed water at horizontal runs and flanges, and load-bearing insulation at supports so the material is not crushed into a moisture trap. Aluminium foil faced insulation with foil tape sealing is the usual approach in the susceptible temperature band.
What refractory is used in fired heaters and reformers?
Refractory castable rated to 1600°C covers most fired heater duty, with high alumina castable to 1750°C where flame impingement is direct or process temperatures are higher. Ceramic fibre blanket serves as backup insulation and in lower-load hot face positions where its low thermal mass is an advantage.
At what surface temperature does insulation become a safety requirement?
Accessible surfaces above roughly 60°C present a contact burn hazard, so personnel protection insulation is specified on that basis rather than on an energy calculation. In plants with extensive hot pipework this is a significant scope in its own right, and it does not always call for the same thickness that heat-loss optimisation would.
Why does fired heater refractory fail between turnarounds?
Usually because of upset events rather than normal operation. Trips, flame impingement, and rapid cooldowns impose thermal shock the lining was not optimised for, and the damage accumulates event by event. This is why lining condition correlates poorly with operating hours and why post-upset inspection is worthwhile.
What sealing materials do you supply for flanges and penetrations?
Graphite packing rated to 450°C for valve and pump sealing, high temperature gaskets, fire sealant S160 rated to 1500°C for penetrations requiring fire stopping, and ceramic fibre blanket for packing irregular openings. Penetration sealing frequently has to satisfy both thermal and fire performance requirements.
Can you support turnaround planning rather than just supply?
Yes, and it is the more useful engagement. Because turnaround windows are fixed and costed in advance, the value is in getting the scope and quantities right beforehand and having materials pre-positioned. Discovering refractory or insulation scope once equipment is open is where turnaround budgets are lost.