ABOUT US
A Precision Sight Glass Factory That Tests Every Window
SIGHTSPEC designs and manufactures industrial sight glasses and sight flow indicators — factory-direct to distributors, OEM equipment builders and process plants worldwide.
Built Around the Glass, Tested Like the Field
A sight glass looks simple — a glass window, a metal frame, a gasket. Then it sits in a reactor at 300°C, gets hit by a cold CIP spray, or sees a pressure surge, and the window that seemed simple becomes the difference between a clear view and a line shutdown. Most sight glass failures are not random: they come from glass with hidden stress, uneven clamping, the wrong glass type for the duty, or seals that do not match the media.
SIGHTSPEC started as a precision sight glass workshop focused on one thing — making windows that survive the duty they are specified for. Our borosilicate glass is produced to DIN 7080 and inspected on arrival; frames are machined from 304 and 316L stainless steel; and every assembled window is pressure-tested before it ships. That discipline is why pharmaceutical, chemical and food processors — and the distributors who serve them — spec SIGHTSPEC windows, and why they reorder.
1/4"–12"
Sight glass sizes (DN8–DN300)
572°F
Borosilicate rating (300°C)
100 bar
Threaded pressure rating
24 h
Quote & technical response
Our Mission
Make precision sight glass manufacturing accessible — honest specifications and factory-direct pricing, with selection support that helps you choose the right window the first time.
Our Promise
Every window is pressure-tested before shipping. If a unit misbehaves in your application, we help diagnose the root cause — glass type, clamping, gasket or installation — rather than sell you another guess.
Factory-Direct
From our manufacturing base to your plant or production line — no middlemen, no markup games, and OEM pricing that reflects factory cost.
Our Quality Process
Four controlled steps between raw glass and a shipped window. Each step is documented, so every order carries batch traceability from glass lot to test report.
Glass Incoming Inspection
Every batch of borosilicate and soda-lime glass is checked on arrival — thermal shock resistance, dimensional tolerance, edge quality and certification documents. Rejections are documented and returned.
Fusion & Edge Finishing
Glass is cut, edge-finished and fused to the metal frame with controlled thermal profiles that prevent stress points — the hidden cause of premature cracking.
100% Pressure Testing
Every assembled window is pressure-tested to its rating before it leaves the bench, with test records kept per batch for full traceability.
Final Inspection & Packaging
Finished windows are inspected for glass clarity, sealing surfaces and finish, then packed with protective corners and labeled with model, size and traceability code.
Certifications & Compliance
Our standard materials and processes align with the certifications process plants ask for most. Certificates and test documentation are issued per batch and included with your shipment.
DIN 7080
Borosilicate sight glass standard — our standard glass is produced and tested to DIN 7080 thermal shock and pressure requirements.
USP Class VI
Biocompatibility-tested materials for pharmaceutical and biotech contact — standard on SG-100 tri-clamp models.
FDA
Food-contact compliant materials and finishes for food and beverage lines, with hygienic surface options to Ra ≤ 0.4 µm.
BPE Compliant
ASME BPE-aligned design and surface finish options for bioprocessing installations.
OEM Capability
Beyond standard windows, we build to your drawing. OEM/ODM projects start with a spec review and pre-production sample, then move to batch production with the same quality system — MOQ from 10 pieces, lead time 15–30 days.
- Custom sizes from 1/4" to 12" and custom flange drilling
- Glass selection: soda-lime, borosilicate, quartz — matched to duty
- Body materials: 304 / 316L SS, Hastelloy, duplex, carbon steel
- Private-label branding: laser engraving, packaging, datasheets
Full details on the OEM / ODM service page.
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Precision Sight Glass Manufacturing
Glass processing · SS fabrication · Pressure testing · Export docs
Talk to the Factory
Send your application details — size, connection, pressure, temperature and media — and get a sight glass recommendation with pricing within 24 hours. English-speaking export support, WhatsApp available for urgent field issues.
Work With a Sight Glass Factory That Answers
Tell us about your application — size, connection, pressure and media — and get a recommendation within 24 hours.