Refractory Practice: Lining Design, Installation, Dry-Out, Inspection and Repair

Refractory practice is the work that turns refractory products into a lining and keeps it in service, in eight steps from lining design, installation and anchoring to dry-out, inspection, failure analysis, repair and recycling. Which step comes first, which standard governs it, and who carries it out?

Monolithic, brick and fiber linings each have their own API installation standard: API Std 936 (5th edition, March 2024), API Std 975 (2nd edition, April 2025) and API Std 976 (2nd edition, October 2024). Every step works with the same refractory materials: shaped, monolithic and insulating products.

The eight steps follow four life-cycle stages: design and placement, a first heat in which water turns to steam that expands about 1,600 times, service under API RP 982 (1st edition, 2023-11-01) in refineries, and tear-out under six EU waste entries, 16 11 01* to 16 11 06.

What Is Refractory Practice?#

Refractory practice is the engineering and site work around a lining: designing its layers, placing and anchoring the material, drying it on the first heat, inspecting and repairing it, and reusing or disposing of it. The API announcement of RP 982 in November 2023 names four functions: thermal protection of the equipment, energy retention and process efficiency, resistance to abrasion and corrosion, and personnel safety. Each practice step protects one or more of these four functions.

A material class is defined by its chemistry, standard and properties, while practice decides how that class is built into a vessel and kept working, whether cast, pumped or gunned, and repaired cold or hot.

Refractory Practice Topics: Eight Pages From Lining Design to Recycling#

Eight practice pages cover the lining life cycle: lining design, installation methods, anchors, dry-out, inspection, failure modes, repair and recycling, one page per step. The table below compares the eight steps by the question each answers, the main standard or rule and its life-cycle stage.

Row order follows the lining life cycle; where no standard exists, a row names the type of guidance. Rows 2, 4 and 5 all cite API Std 936 (5th edition, March 2024), the installation quality-control standard for monolithic linings.

How the Lining Life Cycle Orders the Practice Steps#

The practice steps follow the lining life cycle in four stages: before the first heat, the first heat itself, the service campaign and the end of the campaign, and each stage has its own failure risk. A reader with a new lining starts at design, one with a hot spot on the shell starts at inspection, and one facing a tear-out starts at recycling.

Before the First Heat: Layers, Anchors and Placement Methods#

A lining is designed as working, safety and insulating layers, then placed by one of eight installation methods and, for monolithic and fiber layers, held by anchors. The safety layer is a permanent lining in metal-containing vessels, and the insulating layer is the backup next to the shell. The eight methods are casting with vibration, self-flow and pumping, wet shotcrete, dry gunning, ramming and pounding, dry vibration, bricklaying, and fiber module and blanket installation. Shotcrete, defined by the American Shotcrete Association as mortar or concrete pneumatically projected at high velocity onto a properly prepared surface, gives less rebound and dust than dry gunning (Allen, Shotcrete magazine, Spring 2008).

Metallic anchors expand about 3 times as much as alumino-silicate refractory, so they carry caps, wax or tape that burn out and leave room (Plibrico 2022, producer guidance), and anchor maker RAI places them at least 152 mm (6 in) from expansion joints. Each castable placement method needs its own refractory castables data.

First Heat: Curing, Water Removal and Steam Pressure#

The first heat removes the mixing water from a monolithic lining, and water turned to steam expands about 1,600 times, so the heat-up rate decides whether the lining survives (Jenkins et al. 2011). Curing is hydration at ambient temperature; dry-out is the controlled first heating. Free water leaves at 100 °C (212 °F), while Jenkins, Piper and Proctor (Sulfur Recovery Symposium, 2011) place the critical release of chemically combined water between 204 and 316 °C (400 and 600 °F), sometimes up to 482 °C (900 °F) depending on the cement phases. Temperatures in producer dry-out schedules refer to the hot gas in contact with the lining, not to the lining itself.

Explosive spalling follows when steam pressure inside the lining exceeds its tensile strength. In one plant example, an uncontrolled main-burner dry-out raised the reaction-furnace temperature by about 633 °C/h (1,140 °F/h), and the castable separated 25 to 51 mm (1 to 2 in) from the tube sheet (Jenkins et al. 2011).

In Service: Monitoring, Diagnosis and Hot Work#

A lining in service is watched from outside by shell thermography and embedded thermocouples, opened for visual and hammer-sounding checks during outages. API RP 982 (1st edition, 2023-11-01) covers in-service inspection and assessment of refinery linings. In a producer view, cooling a lining only to look for cracks is discouraged, because ceramic materials fail in tension (Cobane, Hotwork, 2002). Failure modes include explosive spalling, anchor failure, chemical attack, erosion, brick ring loosening on fast cool-down and separation from the shell, and chemical wear by slag, alkali, CO and hydration is the domain of slag and chemical attack.

Refractory maintenance splits into two routes: cold repair cuts back to sound material, replaces anchors, re-casts or guns the area and dries it out locally; hot repair uses hot gunning, slag splashing or ceramic welding.

End of Campaign: Tear-Out, Reuse and Waste Entries#

At the end of a campaign the lining is torn out, and in most cases more than half of installed refractory ends as waste at wrecking (refractories WORLDFORUM 9, 2017). The EU List of Waste gives chapter 16 11 six mirror entries, 16 11 01* to 16 11 06, under Decision 2000/532/EC as amended by Decision 2014/955/EU; the asterisk marks linings containing hazardous substances. In the US, an EPA ORCR letter of 2026-06-25 (RCRA Online 14976) states that spent refractory bricks legitimately reused with only incidental processing are not solid waste under 40 CFR 261.2(e) when 40 CFR 260.43 is met, and states may be more stringent. About 7 % of refractory raw material comes from recycling (LIFE 5REFRACT project case study).

One producer's published recycling route (2023 bulletin) runs from dismantling, sorting and cleaning to stabilization, crushing and sieving, and use. Chromium-bearing tear-out from magnesia-chrome linings carries its own rules, covered under hexavalent chromium in spent magnesia chrome refractories.

Which Standards Govern Refractory Installation and Maintenance?#

Refractory installation and maintenance in refinery and petrochemical service follow four API documents: Std 936 for monolithic linings, Std 975 for brick systems, Std 976 for fiber linings and RP 982 for in-service inspection and assessment. The table below compares the four documents by edition, lining type and scope.

API Std 936 qualifies materials, equipment and personnel, defines the inspector's responsibilities and may supplement an owner's specification. Its inspector certification under the API individual certification program is valid for three years (api.org, checked 2026-10-27). The three standards cover quality control at installation, while RP 982 covers linings already in service, including repair assessment in refinery service.

The full designation, scope and sister documents sit under API 936 refractory installation quality control.

Test Methods for As-Installed Samples and Heat Loss#

As-installed samples are tested for cold crushing strength and modulus of rupture to ASTM C133-24, with ISO 10059-1:2025 and ISO 5014:2025 as the ISO methods for the same properties. The table below pairs ASTM and ISO/EN methods by property, never as equivalents.

EN ISO 10059-1:2025 and EN ISO 5014:2025 replaced their EN 993 parts on 2025-12-09. The heat-loss methods estimate the interface and cold-face temperatures that a lining design must meet.

Calculators, Quotes and Contractor Requests for Lining Work#

Three tools support practice work: a heat-loss calculator for lining thickness and cold-face temperature, a castable quantity calculator for take-off, and two request forms for contractors and suppliers. The three tool links are listed below.

• Heat-loss calculator: refractory heat loss calculator, giving heat flux, interface and cold-face temperatures
• Castable quantity calculator: refractory castable calculator, mass from volume times the producer's dry material per m³
• Tool index: refractory calculators and quote tools

No public per-tonne installation price list was found on 2026-10-27, so installation and dry-out are quoted on factors: lining area and thickness, access and scaffolding, anchors (alloy, count per m²), material tonnage, placement method, crews and shifts, curing environment, dry-out (burners, fuel, thermocouples, days), tear-out and waste class, inspection and test panels, and outage cost per day.

Direct material plus installation cost may be only 40 to 60 % of total refractory-related cost, according to a steel plant buyer's article in refractories WORLDFORUM 9 (2017), so a quote comparison weighs scope and outage time, not only price.

How Does Lining Practice Connect to Materials and Industries?#

Lining practice applies to every refractory form and every industry: material classes set what is installed, industries set where, and practice sets how it is built, dried out and kept. The eight connected sections are listed below.

• Shaped linings: refractory bricks
• Unshaped linings: monolithic refractories
• Backup and fiber layers: refractory insulation
• Grains: refractory raw materials
• Binders that set the dry-out: refractory additives and binders
• Test values behind quality control: properties of refractory materials
• Where linings are installed: refractories by industry
• Full designation list: refractory standards

Monolithic linings carry mixing water and therefore the dry-out risk, while fired brick holds no mixing water and needs no curing.

Who Carries Out Each Practice Step?#

Four parties share a lining job: the material manufacturer sets the dry-out schedule, the installer or designer writes the plan, the owner approves it and a dry-out contractor executes it (Jenkins et al. 2011). Refractory contractors install linings by casting, gunning, shotcrete, bricklaying or fiber module work, dry them out, inspect and repair them, and API Std 936 (5th edition, March 2024) defines the inspector's role on monolithic jobs. A request to a contractor should name the lining type, the area or tonnage and the outage window.

Which Safety Rules Apply to Tear-Out and Cutting?#

Cutting and tearing out linings releases respirable crystalline silica, which OSHA limits to 50 µg/m³ as an 8-hour TWA with an action level of 25 µg/m³ (29 CFR 1910.1053, construction 29 CFR 1926.1153, effective 2016-06-23). The EU limit is 0.1 mg/m³, respirable fraction, under Directive (EU) 2017/2398 (transposition by 2020-01-17). Fiber, chromium and pitch rules sit under refractory health and safety.