Verified 31 August 2026

Process sight glass assemblies (borosilicate) manufacturers in Germany

Process sight glass assemblies (borosilicate) are made by a mix of specialist glass manufacturers, OEMs that produce DIN-style sight discs and assemblies, and fabricators that assemble glass into metal flanges and housings. Buyers should specify the glass type, applicable DIN/industry standard, mechanical connection style, and operating conditions when sourcing in Germany or from German-focused suppliers.

Get contact emails + AI outreach — free trial

6 verified manufacturers

  • L.J. Star

    “"We supply a variety of sight windows and ports with borosilicate or soda-lime glass. Our product line includes METAGLAS fused sight glasses"”

  • SXET

    “"Custom Borosilicate Sight Glass Manufacturer - Glass supplies borosilicate sight glasses for OEM equipment builders, process plants, and replacement part buyers. We can produce standard DIN-style discs"”

  • GMM Pfaudler

    “"Sight Glasses - GMM Pfaudler ... sight glasses were manufactured according to DIN 28121 with a borosilicate glass disk fixed by screwing it to a chamber on a glass-lined ring"”

  • SwiftGlass

    “"MAXOS® safety sight and level gauge glasses made of borosilicate glass are perfect for temperatures up to 300 °C"”

  • CRP US

    “"CRP's offers a range of highly reliable tubular sight glasses ... They are made from heavy wall Borosilicate Glass"”

  • I-LumiStar

    “"DIN 28120 Sight Glass Assembly | Vessel Sight Glass Manufacturer"”

Compiled from public sources and refreshed periodically. Always verify certifications and capabilities directly with the manufacturer before ordering.

Need their contact details?

Source365 finds verified contact emails for manufacturers like these and drafts the RFQ outreach for you — directly from the inquiry email in your Outlook inbox.

Start free 14-day trial

What to specify in your RFQ

Manufacturers quote faster and more accurately when your request covers these points.

  • Glass type and composition

    Specify borosilicate grade (e.g., 3.3 borosilicate), required thermal/shock resistance and any chemical compatibility needs.

  • Standard / flange style

    State the DIN standard (e.g., DIN 7080, DIN 28120/28121) or other flange/connection type used on your vessel.

  • Disc dimensions and thickness

    Provide outer diameter, bore diameter, usable viewing diameter and required glass thickness or pressure rating.

  • Operating conditions

    List maximum temperature, operating pressure and any vacuum, cyclical thermal or pressure shock conditions.

  • Quantity and lead time

    Give required quantity, batch vs. ongoing supply and desired delivery timeline to obtain MOQ and pricing.

  • Gasket / sealing materials

    Specify gasket material compatibility (e.g., PTFE, EPDM, Viton) and whether you need welded, bolted or screwed retaining hardware.

  • Inspection and certification

    Request material certificates, DIN compliance, and any factory inspection or traceability documentation you require.

Sourcing FAQ

How do I verify a supplier actually manufactures borosilicate sight glasses?
Ask for factory evidence such as product pages stating manufacture, photos of production, declared DIN product codes, and material certificates showing borosilicate glass grade; supplier product pages in the search evidence above explicitly identify manufacturers.
What minimum order quantities (MOQs) should I expect?
MOQs vary by supplier and product (custom-molded discs vs. standard DIN discs); ask each manufacturer for their MOQ for standard versus custom sizes when requesting a quote.
Which standards or certifications matter for process sight glasses?
Common standards include DIN 7080, DIN 28120/28121 for disc dimensions and assembly practices; request material certificates, conformity to the cited DIN standard, and any customer-specific QA or traceability documents.
What drives lead time for borosilicate sight glass assemblies?
Lead time depends on whether the disc is a standard DIN size (shorter lead time), custom machining, quantity, required heat treatment/annealing and any additional assembly (flanges, gaskets).

Related categories