Upper, Metering & Lower Nozzles for Ladle and Tundish Flow Control

Upper, metering and lower nozzles are the least glamorous items in the flow-control package and among the most consequential. They are also machined components: a nozzle with excellent chemistry that does not seat correctly will leak or fail regardless of its material properties.

Position Determines Duty

• Upper (collector) nozzle — sits above the sliding plate, receives steel from the vessel, and sees the highest ferrostatic pressure.
• Metering / lower nozzle — sits below the plate, controls discharge, and connects into the shroud or mould.

Both take mechanical seating load, and both see rapid temperature change at start of cast. That combination is why the bowl rim is specified differently from the body.

Why Body and Rim Are Different Materials in One Part

Every XZK nozzle grade runs a two-property design. The body needs thermal shock resistance above all — it sees the steepest gradient. The bowl rim takes mechanical contact from the stopper or plate and resists wear and deformation at that surface. So the rim is denser and stronger while the body stays more tolerant of thermal cycling:

• Body — 2.30 g/cm³, porosity ≤18%, CCS ≥20 MPa, MOR ≥8 MPa.
• Bowl rim — 2.60–2.70 g/cm³, porosity 16–19%, CCS 15–25 MPa.

Magnesia Bowl Rim for Aggressive Grades

XZK-SLT-M carries a 60% MgO bowl rim rather than an alumina one. On high-manganese and high-oxygen grades, alumina dissolves at the contact surface, and rim wear becomes the reason the nozzle is changed. If your symptom is rim wear rather than body cracking, this is usually the fix.

Fit Is Part of the Specification

We machine to the major mechanism types, including Interstop and Vesuvius styles, and verify interface dimensions before production. Send the mechanism model or a drawing of your current set — this is not a place to approximate.

Supply

Quoted per set, typically 200–500 pieces minimum, 20–35 days from drawing approval. Dimensional inspection reports, batch test data and material certificates ship with every order, and third-party inspection can be arranged.

Where This Grade Sits in the Lining System

Flow-control refractories are consumed on the caster's schedule, so the specification is as much about dimensional repeatability and interchangeability with your existing mechanism as it is about composition. A plate or shroud that fits but varies by a millimetre between lots costs more in breakouts than it saves in unit price.

XZK supplies upper & metering nozzle as one zone of a zoned package rather than as a standalone item: the grades normally zoned alongside it — among them slide gate plate — are documented on the continuous casting functional refractories page, and the vessel-level architecture — where each zone starts and ends, and which mechanism actually limits the campaign — is set out on the tundish flow control and steel ladle and RH/VD pages.

The Colakoglu Metalurji slab caster flow control programme reference documents how this class of material performed in full service, with the measured campaign figures rather than datasheet values.