METAGLAS® Type 903 — Aseptic Flush-Wall Sight Glass (O-Ring Sealed)
The METAGLAS® Type 903 is a metal-fused sight glass engineered for aseptic applications.
Its flush-wall design on both the air side and product side eliminates dead zones, maximises cleanability,
and protects product integrity. An O-ring sealing concept delivers repeatable, hygienic installation with
zero drama under CIP/SIP regimes.
Design & Construction
Geometry:Flush-wall, dead-zone-free on airside and product side
Sealing:O-ring seal (EPDM, FKM/Viton®, PTFE or per process spec)
Glass: METAGLAS® metal-fused borosilicate with permanent compressive pre-stress
Body: Stainless steel (e.g., 1.4404 / 316L); alternative alloys on request
Finish: Polished/electropolished for full CIP/SIP compatibility
Performance: High resistance to pressure cycling, thermal shock, and vibration
Envelope: Pressure/temperature dependent on size and materials (data on request)
Applications
Pharmaceutical & biotech reactors, fermenters, and sterile transfer lines
Food, dairy & beverage processing with stringent hygienic requirements
CIP/SIP loops, aseptic filling, and inspection ports
Cosmetics and nutraceuticals where zero hold-up matters
Key Advantages:
Flush on both faces — no product traps, easy drainability
O-ring sealing — quick, repeatable assembly and clean service
Metal-fused glass — no gasket creep at the glass/metal interface
Optical clarity with long service life under aseptic duty
Low profile for maximum viewing and minimum build height
Specify DN/size, interface standard, media, temperature/pressure envelope, body alloy, and O-ring material.
John Moncrieff Ltd will configure Type 903 to your duty with the correct seal set and documentation pack (PED/QA).
