METAGLAS® Type 76 — Circular Metal-Fused Sight Glass (Form A)
The METAGLAS® Type 76 is a circular, metal-fused sight glass Form A
featuring a flat sealing surface. It is designed for installation on
weld-neck flanges with sealing surfaces to
EN 1092-1/12C and EN 1092-1/13C, as well as
nozzles DIN 28115 / 28025 and base flanges DIN 28117.
The assembly acts as a direct replacement for DIN 28121 sight glass armatures.
Manufactured using the proven METAGLAS® fusion process, the glass is permanently fused into a machined steel ring,
creating internal compressive stress within the glass. This ensures superior resistance to pressure, thermal shock,
and vibration when compared to conventional gasketed sight glass systems.
Design & Construction
Type: Circular metal-fused sight glass, Form A (flat sealing surface)
Standards: EN 1092-1/12C and 13C | DIN 28115 / 28025 | DIN 28117 base flanges
Compatibility: Sight glass in traction as replacement for DIN 28121
Sealing Surface: Flat face for use with appropriate gasket | no sealing ledge required
Glass-to-Metal Bond: Permanent fusion providing mechanical pre-stress and leak-tight seal
Pressure/Temperature Range: Dependent on nominal size and material selection (available on request)
Applications
Process vessels and reactors with DIN or EN flange connections
Chemical and petrochemical plant installations
Pharmaceutical and biotechnology equipment
Steam and utility systems requiring direct visual inspection
Retrofit replacement for DIN 28121 sight glass assemblies
Key Advantages:
Fully compatible with EN 1092-1 and DIN flange standards
Mechanically prestressed for exceptional pressure and thermal resistance
Leak-tight metal-fused construction — no gasket creep or loosening
Maintenance-free service with extended lifespan
Drop-in replacement for DIN 28121 units
John Moncrieff Ltd supplies certified METAGLAS® Type 76 assemblies for
industrial process applications — precision-engineered, pressure-tested, and fully compliant with EN and PED requirements.
