METAGLAS® Type 74 — Metal-Fused Sight Glass with Tongue (DIN 2512)
The METAGLAS® Type 74 is a metal-fused sight glass with an integral sealing tongue
(groove per DIN 2512). It’s built for nozzles DIN 28115 / DIN 28025 and
weld-neck flanges DIN 2632, 2633, 2634, 2635, 2636 using sealing surface
Form N (tongue-and-groove joint). If you run tongue/groove, this is the right unit—no half measures.
Design & Construction
Interface: Sight glass with tongue; mates to groove per DIN 2512 (Form N)
Standards: Nozzles DIN 28115 / 28025; weld-neck flanges DIN 2632–2636
Seal Concept: Metal-fused glass ring delivers permanent mechanical pre-stress and leak-tightness
Bonding: Glass fused into steel ring — zero gasket creep at the glass interface
Gasketing: Use matching tongue/groove gasket set per DIN 2512 for the flange joint
Performance Envelope: Pressure/temperature dependent on size and materials (available on request)
Compatibility & Fitment
Direct fit to Form N sealing faces on DIN 2632–2636 weld-neck flanges
Suited to vessel nozzles per DIN 28115 and DIN 28025
Ideal as a robust alternative to conventional DIN 7080/7079 glass in tongue/groove joints
Applications
Process vessels and reactors requiring DIN tongue/groove sealing
Chemical, petrochemical, pharma, and utilities where joint integrity is non-negotiable
Retrofits where Form N is already specified across the line
Key Advantages:
True tongue-and-groove engagement per DIN 2512 (Form N)
Metal-fused construction = high mechanical/thermal resilience
Leak-tight, maintenance-free optical seal at the glass/metal interface
Clean, repeatable bolting with the correct DIN gasket stack-up
Specify nominal size, flange standard, materials, and duty. We’ll deliver the correct Type 74 configuration
with the right gasket set and fasteners—no guesswork, no rework.
