Case study · Retrofit

Bringing a sealed quench furnace back into production

A bearing manufacturer's sealed quench furnace was not in working condition. We rebuilt it across eight workstreams and handed it back to production in January 2026.

Furnace:: Sealed quench furnace

Results

What the project delivered.

Workstreams in one revamp: 8
Quench-oil level sensors: 2 → 4
Staged trials before handover: 4
Handed back to production: Jan 2026

The furnace was not in working condition when we started. It was handed back to production in January 2026.

Release came only after a Temperature Uniformity Survey referenced to AMS 2750 and four staged trials: dummy, cold, scrap load and a fresh material charge.

Overview

The project.

Rebuilt chamber roof and walls in new refractory brick

Case study · Retrofit

What we did

A bearing manufacturer's sealed quench furnace was not in working condition. The lining, the instruments, the atmosphere panel and the controls all needed work before it could run again.

Patching individual failures would have left a furnace that nobody could trust at temperature. We treated it as one system: rebuild the hot face, replace every field instrument, take cooling water out of the atmosphere zone, and rewrite the PLC so the new hardware runs as a whole.

Why cooling water had to go

Water close to a controlled furnace atmosphere is a standing risk: a leak puts moisture into the furnace. Converting both the recirculation-fan cooling and the heat exchanger to air removed that risk, along with the scaling, corrosion and leak maintenance that water cooling brings.

CustomerBearing manufacturer
EquipmentSealed quench furnace (SQF)
ConditionNot in working condition
ScopeComplete retrofit and modernisation
HandoverJanuary 2026

Scope of work

How it was done.

01
Refractory lining
The old lining was stripped out and the brick lining and hearth rebuilt with better refractory and insulation, aligned for stable loads and even heating.
Before
After
02
Instrumentation
Every field instrument was removed and replaced with new sensors and controllers, then integrated with the PLC and control panel.
Before
After
03
Atmosphere panel
The nitrogen, methanol and carrier-gas mixing panel was rebuilt with new flow meters, solenoid valves, non-return valves, pressure gauges and switches, with interlocks against atmosphere imbalance.
Before
After
04
Fan cooling
Recirculation-fan cooling was converted from water to air, removing leakage, scaling and corrosion and keeping water away from the atmosphere.
Before
After
05
Heat exchanger
The water-cooled heat exchanger was replaced with an air-cooled unit for the same reasons, at lower running cost.
Before
After
06
Quench-oil level
Oil level sensing went from two sensors to four, with PLC alarms for low and high level to prevent shortage or overflow during quenching.
Before
After
07
Controls & PLC
The control panel was rebuilt around the new instruments and the PLC program rewritten: automated heating, quenching and atmosphere sequences, recipes, interlocks and emergency shutdowns.
Before
After
08
Validation & handover
A Temperature Uniformity Survey, four staged trials (dummy, cold, scrap load and fresh material charge) and operator training, then handover of the scope, test results and manuals.
Survey
Trials