Refractory technology3 min24.07.2026

Overhauling a low-pressure die casting furnace: when the general overhaul is the better investment

A low-pressure die casting furnace is a refractory-lined pressure vessel — and it can be fully reconditioned instead of replaced. What counts technically during the overhaul.

Fully overhauled low-pressure die casting furnace for aluminium before return to the customer

A second life for industrial plant is more than a repair. This low-pressure die casting furnace went through a complete reconditioning process — from collection at the customer's site to the return of a comprehensively overhauled unit. The aim is not a cosmetic refresh, but restored reliability and a lastingly extended lifespan.

How a low-pressure die casting furnace works

Unlike a melting or holding furnace, a low-pressure die casting furnace (LPDC) is a closed pressure vessel. A slight gas overpressure of around 0.2 to 0.7 bar is built up above the aluminium bath. This pressure forces the melt upwards from below in a controlled manner through a riser tube and into the die — with few bubbles and precisely metered. It is exactly this design that places particular demands on the refractory lining: it has to withstand the aluminium and at the same time form part of a leak-tight pressure system.

Opened low-pressure die casting furnace with a view of the bath chamber and penetrations during the overhaul — Opened furnace during reconditioning — bath chamber, penetrations and sealing faces are completely reworked

How our fitters go about it

Two SBS fitters taking measurements inside the stripped-out low-pressure die casting furnace — Measuring up and recording findings in the stripped-out furnace – the basis for the complete relining

Fitters preparing the furnace housing with forklift support — Preparing the housing – every move counts, supported by our own team

Installed formwork in the low-pressure die casting furnace before casting the new lining — Dimensionally accurate formwork for the monolithic casting of the new lining

What matters during the overhaul

Bath lining: non-wetting, corundum-resistant materials prevent liquid aluminium from infiltrating and corundum from closing up the cross-section — the basis for service life and melt cleanliness.
Riser tube and tube seat: the riser tube is the most heavily loaded component. The seat and connection have to be dimensionally accurate and tight so that metering remains reproducible.
Pressure tightness: as a pressure vessel, the furnace has to remain gas-tight at the lid, the penetrations and the sealing faces — one leak costs metering accuracy and process reliability.
Dimensional accuracy: the geometry of the bath, riser tube and lid directly determines casting quality. Millimetres count here.
Controlled first heat-up: after relining, bound water only escapes safely from the structure along a defined heat-up curve with holding stages.

Detail view of the opened furnace chamber of a low-pressure die casting furnace with renewed refractory lining — Detail of the reworked chamber — renewed lining and sealing faces as the basis for further operation

General overhaul instead of buying new

A fully reconditioned furnace achieves the reliability of a new unit — at a fraction of the investment and with a considerably shorter procurement time. Final assembly and commissioning at the customer's site are no longer part of refractory construction, but of the final installation of the plant.

The overhauled unit

Fully reconditioned low-pressure die casting furnace with charging opening, ready for return — The reconditioned low-pressure die casting furnace – housing blasted, openings and sealing faces renewed

Low-pressure die casting furnace with opened chamber after the overhaul — View of the opened chamber with renewed refractory lining

Overhauled low-pressure die casting furnace in the workshop seen from the side — The finished unit before delivery – functionality and service life restored

Every project of this kind calls for technical expertise, precision and attention to every detail — with the result of a unit that will be in reliable service for many years to come.

At a glance

0.2–0.7 bar

gas overpressure above the aluminium bath

Pressure vessel

refractory lining as part of a leak-tight system

Riser tube

the most heavily loaded component