Integrated Steel Plant
Process Overview
Integrated Steel Plant — Process Overview
An integrated steel plant converts coal and iron ore into finished steel. Coke ovens carbonise coal and recover tar and ammonia from the gas; the blast furnace reduces iron ore to hot metal, with its gas cleaned in scrubbers and its slag granulated with water. Steel from the converter is continuously cast, then rolled in the hot strip mill with high-pressure descaling, pickled in hydrochloric acid and cold rolled with oil emulsion. Large water and acid circuits serve every stage.
For alumina refining, copper and zinc see Alumina & Non-Ferrous Metals.
Key Sealing Challenges
- Scale and dust: mill scale, slag and blast furnace dust wear soft faces; slurry cartridges with SiC pairs and a clean flush are used.
- High pressure: descaling pumps discharge at 150–250 bar. The seal is sized for its own seal-chamber pressure.
- Hot hydrochloric acid: pickle liquor attacks stainless steel and titanium, and its ferric ions attack Hastelloy B; non-metallic wetted parts are used.
- Ammonia and tar: coke oven flushing liquor needs FFKM and a pressurised barrier.
What mechanical seal is used on steel mill descaling pumps?
High-pressure descaling pumps typically use a high-pressure balanced cartridge seal (e.g. Gipfel HP760) with silicon carbide vs. silicon carbide faces on an API Plan 11 flush. Although discharge is 150–250 bar, the seal is sized for seal-chamber pressure (suction or balance-line pressure), which must be confirmed from the pump data sheet.
Root-Cause Failure Analysis — Field Example
Symptom: Scale water pump seal fails every few weeks; faces grooved, springs packed with scale.
├── Incorrect Response: "Change to harder springs."
├── Diagnostic Evidence Required:
│ ├── Are mill scale particles reaching the faces with no flush?
│ ├── Are the springs exposed to the product?
│ └── Is oil in the water swelling the elastomers?
└── Engineered Solution:
├── Slurry cartridge with external springs and SiC vs SiC faces.
├── API Plan 32 filtered water flush.
└── FKM elastomers for oily scale water.
Frequently Asked Questions
Why not use titanium on pickling acid pumps?
Hot hydrochloric acid attacks titanium. Hastelloy B resists pure HCl but is attacked by the ferric ions in pickle liquor, so PTFE, ceramic or tantalum wetted parts are used.
Which seal suits coke oven flushing liquor?
A double cartridge seal on a pressurised barrier with SiC vs SiC faces and FFKM. The liquor contains ammonia, which attacks FKM, and tar, which attacks EPDM.
Related: Alumina & Non-Ferrous Metals · Mining Slurry · Coal-Fired Thermal Power · Chlor-Alkali.
Request a Seal Selection
Send your pump make and model, fluid, temperature, pressure, shaft size and speed to info@gipfelengg.com or use our enquiry form. Gipfel Engineering (ISO 9001:2015, NSIC-registered MSME, Mumbai) designs and manufactures mechanical seals, seal support systems and process pumps.
Equipment solutions: Split-Case Pumps · Slurry Pumps · Blowers.
Pump Duty & Mechanical Seal Selection Matrix
Typical values for selection guidance only. Final selection is made against the customer duty sheet.
| Pump duty | Fluid | Typical temp. | Typical pressure (bar) | Seal arrangement | Faces / elastomer | API piping plan |
|---|---|---|---|---|---|---|
| Blast Furnace Closed Cooling Water Pump | Soft or DM cooling water | 40–60 °C | 6–12 bar | Balanced multi-spring cartridge | SiC vs carbon / EPDM | API Plan 11 |
| BF Gas Scrubber / Slag Granulation Water Pump | Water with dust or slag particles | 30–90 °C | 2–6 bar | Slurry cartridge, external springs (catalogue ref. HS860) | SiC vs SiC, or tungsten carbide pair / EPDM | API Plan 32 (clean water flush) |
| Coke Oven Flushing Liquor Pump | Ammoniacal liquor with tar | 70–80 °C | 3–6 bar | Double cartridge, back-to-back (pressurised) | SiC vs SiC / FFKM (ammonia rules out FKM; tar rules out EPDM) | API Plan 53A (barrier ≥ 1.4 bar above seal chamber) |
| Continuous Caster Mould Cooling Water Pump | Clean DM or soft water | 30–50 °C | 6–12 bar | Balanced multi-spring cartridge | SiC vs carbon / EPDM | API Plan 11 |
| High-Pressure Descaling Pump | Filtered water | Ambient–40 °C | Discharge 150–250 bar; seal sees suction / balance-line pressure — confirm per pump | High-pressure balanced cartridge, stationary springs (catalogue ref. HP760) | SiC vs SiC / EPDM | API Plan 11 |
| Scale Water / Roll Cooling Pump | Water with mill scale and oil | 30–50 °C | 3–10 bar | Slurry cartridge, external springs (catalogue ref. HS860) | SiC vs SiC / FKM | API Plan 32 (filtered water flush) |
| Cold Mill Emulsion Pump | Oil-in-water rolling emulsion | 50–60 °C | 4–10 bar | Balanced multi-spring cartridge | SiC vs carbon / FKM | API Plan 11 |
| Pickling Acid Circulation Pump | 15–20 % HCl with iron chlorides | 70–85 °C | 2–4 bar | Lined or non-metallic pump; seal wetted parts in PTFE, ceramic or tantalum (not titanium; Hastelloy B is attacked by ferric ions in pickle liquor). Selection on request | Sintered SiC vs sintered SiC / FFKM | API Plan 11 |
| Pickling Fume Scrubber Pump | Dilute HCl scrubber water | 30–50 °C | 2–4 bar | Lined or non-metallic pump; seal wetted parts in PTFE, ceramic or tantalum (not titanium; Hastelloy B is attacked by ferric ions in pickle liquor). Selection on request | Sintered SiC vs sintered SiC / FKM or FFKM | API Plan 11 |
| Lime Slurry Neutralisation Pump | Lime slurry, abrasive | Ambient–40 °C | 2–4 bar | Slurry cartridge, external springs (catalogue ref. HS860) | SiC vs SiC / EPDM | API Plan 32 or Plan 62, per seal design |
Reviewed by Gipfel Engineering’s technical team.
Technical Information Disclaimer
The information on this page, including process descriptions, flow diagrams, operating ranges, seal arrangements, materials and piping plans, is general technical guidance for information only. Values shown are typical industry ranges, not guaranteed ratings or specifications of any Gipfel Engineering product. Each application differs. Seal selection, material compatibility, installation and operation must be verified by qualified personnel against the specific equipment data sheet, process conditions, applicable codes and the pump manufacturer’s instructions. A binding recommendation is given only in a written quotation or technical offer from Gipfel Engineering.
References to standards (such as API 682, ISO 21049, ISO 3069, FDA 21 CFR 177.2600 and NACE MR0175 / ISO 15156) describe common industry practice. They do not mean that any product is certified, qualified or approved to that standard unless this is confirmed in writing for a specific order. Third-party company and product names, including “equivalent to” references, are used for identification only and remain the trademarks of their owners. No affiliation, endorsement or OEM approval is implied.
Compliance with safety, hazardous-area, environmental and statutory requirements at the user’s site remains the responsibility of the plant owner or operator. To the extent permitted by law, Gipfel Engineering accepts no liability for loss or damage arising from reliance on this general information without a confirmed written recommendation. Content may change without notice.