UB Engineering Global is a trusted CI fire door manufacturer in India, supplying precision-cast, heat-resistant cast iron fire doors for industrial boilers, furnaces, kilns, and thermal processing equipment. Based in Ludhiana, Punjab, we manufacture and supply CI boiler fire doors, furnace inspection doors, ash pit doors, and custom-sized cast iron fire doors to industries across India, including steel plants, cement plants, textile mills, chemical industries, and power generation facilities.
With 23+ years of manufacturing experience in industrial fabrication and refractory solutions, UB Engineering Global brings quality, durability, and application-specific expertise to every CI fire door we produce.
What Is a CI Fire Door?
A CI fire door (Cast Iron fire door) is a heavy-duty industrial door fabricated from grey cast iron or SG (Spheroidal Graphite) iron, designed to withstand continuous exposure to extreme heat, open flame, radiant heat, and abrasive ash-laden environments inside industrial boilers and furnaces.
Unlike standard steel doors, CI fire doors are engineered specifically for high-temperature industrial applications where temperatures can reach 800°C to 1,200°C. They are used as access doors, inspection doors, ash doors, and fire doors on solid fuel boilers, oil-fired boilers, biomass-fired furnaces, and coal-fired thermal plants.
Key material properties of CI fire doors:
- Cast iron withstands temperatures up to 1,200°C continuously
- High compressive strength, no warping or deformation under sustained heat
- Natural corrosion resistance in high-temperature environments
- Excellent thermal mass absorbs and radiates heat without cracking
- Low maintenance: no coatings, no treatments required in service
Types of CI Fire Doors We Manufacture
CI Boiler Fire Door
The standard CI boiler fire door is fitted on the fire side (combustion chamber) of solid fuel, coal-fired, and biomass-fired boilers. Available in square and rectangular profiles, hinged or bolted, with integral frame and locking pin. Sizes from 300×300 mm to 700×700 mm; custom sizes available.
CI Ash Pit Door
Fitted at the bottom of the boiler grate to provide access for ash removal from the ash pit. Designed to handle high radiant heat from above while remaining operable for daily ash clearing. Available in hinged and lift-off configurations.
CI Furnace Inspection Door
Used on industrial furnaces, kilns, and reheating furnaces to allow operators to visually inspect the combustion chamber, check flame pattern, and monitor furnace condition without a full shutdown. Fitted with a small peephole or inspection port.
CI Charging Door
Fitted on the fuel feeding side of solid-fuel boilers and biomass furnaces. Designed to be opened repeatedly during fuel charging cycles, reinforced hinge and frame construction for high-cycle durability.
Custom CI Doors
UB Engineering Global manufactures CI fire doors to customer drawings and site specifications. Rectangular, circular, and custom-profile doors with flanged frames, counterweights, refractory-lined variants, and special hinge configurations are available on request
CI Fire Door Specifications
| Parameter | Details |
|---|---|
| Material | Grey Cast Iron (CI) / SG Iron (Spheroidal Graphite Iron) |
| Temperature Rating | Up to 800°C–1,200°C depending on grade |
| Standard Sizes | 300×300 mm, 400×400 mm, 450×450 mm, 500×500 mm, 600×600 mm, 690×590 mm |
| Custom Sizes | Available as per drawing or sample |
| Door Types | Boiler Fire Door, Ash Pit Door, Inspection Door, Charging Door |
| Opening Style | Hinged / Lift-off / Bolted |
| Surface Finish | Red Oxide / Black Paint / As Required |
| Frame | Integral cast iron frame with seating surface |
| Hardware | Cast iron pin, hinge, and latch |
| Supply Area | Pan-India |
| MOQ | 1 piece onwards |
Applications of CI Fire Doors
CI fire doors from UB Engineering Global are used across a wide range of industrial sectors and equipment types:
Industrial Boilers—Fire doors, ash pit doors, and inspection doors for solid fuel, coal-fired, and biomass-fired fire tube and water tube boilers in textile mills, food processing plants, chemical industries, and utilities.
Thermopac Heaters — Access and inspection doors for thermic fluid heaters (thermopacs) used in textile dyeing, food processing, and chemical process industries.
Reheating Furnaces — Inspection and charging doors for pusher-type and walking beam reheating furnaces in steel rolling mills and forging plants.
Cement Kilns—Inspection doors for cement rotary kiln supporting equipment, preheater systems, and auxiliary firing systems.
Biomass & Agro Waste-Fired Boilers — Heavy-duty CI doors for rice husk, bagasse, and agricultural waste-fired boilers in food processing and sugar industries.
Incinerators — Charging doors and ash doors for industrial waste incinerators in pharmaceutical, chemical, and municipal waste handling facilities.
Foundry Furnaces — Access doors for cupola furnaces and reverberatory furnaces in iron and steel foundries.
Power Plants — Coal-fired and biomass-based captive power plants requiring reliable boiler access hardware.
ndustries We Serve
UB Engineering Global supplies CI fire doors to customers across seven major industrial sectors in India:
- Textile Industry — Boiler fire doors for thermopac and steam boiler systems in dyeing and processing mills across Punjab, Haryana, and Gujarat
- Steel & Foundry Industry — Furnace inspection and charging doors for reheating furnaces and foundry cupolas
- Cement Industry — Auxiliary equipment doors for rotary kiln support systems
- Chemical & Pharmaceutical Industry — Incinerator and boiler access doors in chemical processing plants
- Food & Agro Processing Biomass boiler fire doors for rice mills, sugar mills, and food processing units
- Power Generation — Boiler fire doors for captive power plants and co-generation units
- Paper & Pulp Industry — Steam boiler and recovery boiler access doors
Why Choose UB Engineering Global for CI Fire Doors?
23+ Years of Manufacturing Experience
Since 2001, UB Engineering Global has supplied industrial equipment and refractory solutions to steel, cement, textile, and chemical plants across India. Our CI fire doors are manufactured with the same quality standards we apply to all industrial products — premium raw material, controlled casting, and dimensional accuracy.
In-House Casting & Manufacturing
We do not source standard CI doors from traders and resell them. Our CI fire doors are manufactured to your specification — including custom sizes, special hinge configurations, and refractory-lined variants — giving you a product built for your exact equipment.
Consistent Quality, Every Piece
Each CI fire door is inspected for casting integrity, dimensional accuracy, hinge operation, and surface finish before dispatch. No porous casting, no dimensional variation, no hinge binding.
Pan-India Supply
We supply CI fire doors to customers across Punjab, Haryana, Delhi NCR, Uttar Pradesh, Rajasthan, Gujarat, Maharashtra, and other industrial states with reliable packaging and timely dispatch.
Technical Support
Our team helps you identify the right door type, size, and material grade for your boiler or furnace — whether you are specifying for a new installation or replacing a damaged door on a running plant.
Competitive Pricing
Direct manufacturer pricing with no middlemen. We offer competitive rates for both single-piece and bulk orders with flexible lead times.
Manufacturing & Quality Process
Every CI fire door we manufacture goes through a structured production process:
- Raw Material Selection — Grey CI or SG iron is selected based on the required temperature rating and mechanical properties. Only certified, tested alloys are used.
- Pattern & Mould Preparation — Patterns are made to exact dimensional drawings. Moulds are prepared using controlled sand casting techniques.
- Casting & Pouring — Molten iron is poured at controlled temperature to ensure dense, void-free casting with uniform wall thickness.
- Cooling & Shakeout — Controlled cooling prevents stress cracking and maintains dimensional stability.
- Fettling & Machining — Gates, risers, and flash are removed. Seating surfaces and hinge bores are machined for smooth operation.
- Inspection — Each door is inspected for porosity, dimensional accuracy, hinge alignment, and surface condition before finishing.
- Surface Treatment — Red oxide or black paint finish applied as standard. Special finishes on request.
- Packing & Dispatch — Doors are packed to prevent transit damage and dispatched with full batch records.
Frequently Asked Questions
Standard grey cast iron CI fire doors are rated for continuous service up to 800°C–1,000°C. SG iron (Spheroidal Graphite Iron) variants can handle up to 1,200°C. The correct grade depends on your boiler or furnace operating temperature. Our team will recommend the right specification for your application.
CI boiler fire door is fitted on the combustion chamber (fire) side of the boiler and is exposed to direct flame and radiant heat. An ash pit door is fitted at the bottom of the boiler to provide access for ash removal — it faces radiant heat from above but is not directly in the flame path. Both are made from cast iron but may differ in size, hardware configuration, and thickness.
Yes. UB Engineering Global manufactures CI fire doors in any size as per your drawing or sample. Custom rectangular, square, and circular profiles are available with custom hinge and latch configurations.
Standard sizes range from 300×300 mm to 700×700 mm. The most commonly ordered sizes are 400×400 mm, 450×450 mm, 500×500 mm, and 600×600 mm. Custom sizes outside this range are available on request.
Yes. For very high temperature applications, CI fire doors can be supplied with refractory castable or ceramic fibre lining on the hot face to further improve heat resistance and reduce heat conduction to the exterior. Contact us with your application details for a specification.
Grey Cast Iron (CI) is the standard material cost-effective and suitable for most boiler fire door applications up to 1,000°C. SG Iron (Spheroidal Graphite Iron, also called ductile iron) has higher tensile strength, better impact resistance, and improved high-temperature performance preferred for demanding applications above 1,000°C or where mechanical shock is present.
We supply from 1 piece upwards. Whether you need a single replacement door or a bulk order for a new installation, UB Engineering Global can fulfil your requirement with the same quality standards.
Share your requirement door type (fire door, ash door, inspection door), size (or drawing), quantity, and delivery location and our team will respond with a competitive quotation within 24 hours.
Get a Free Quote
Looking for a reliable CI fire doors manufacturer in India? Share your door type, size, quantity, and location and UB Engineering Global will provide a competitive quotation within 24 hours.
📞 Call/WhatsApp: +91 98558 33496 | +91 99156 22223
📍 Location: Lakhowal Link Road, Kohara Chowk, Ludhiana, Punjab 141112
🌐 Supply: Pan-India — Punjab, Haryana, Delhi NCR, Gujarat, Maharashtra & all states