ANSI Straight-Through Sight Glass (Inline / Tubular Sight Flow Indicator)
ANSI straight-through sight glass (inline tubular sight flow indicator) — flanged ANSI 150/300 options, borosilicate tube, stainless steel ends. Datasheet & COA available.
Description
ANSI straight-through sight glass provides a robust, inline visual check of fluid presence and condition. It fits standard ANSI flanges and is ideal for process piping, steam service and industrial visual monitoring. Choose flanged, threaded or sanitary connections and borosilicate or toughened tube materials for your application.
Why choose our ANSI straight-through sight glass?
- ANSI compatibility: We supply sight glasses that match ANSI flange dimensions (ANSI 150 / 300 / 600 classes) for fast replacement and reliable sealing.
- Clear inspection: Tubular sight glass gives unobstructed inline view for flow, color and clarity checks.
- Material options: Borosilicate glass (standard), toughened glass or quartz for higher temperature or chemical demands.
- Durable body: Stainless steel (304 / 316) or carbon steel housings with PTFE or FKM gaskets.
- Serviceable design: Three-piece and full-view variants allow quick tube replacement without removing the assembly.
Product at a glance
| ANSI | D | BL (DIN F1) | d1 | Glasplatte | |||
|---|---|---|---|---|---|---|---|
| 150 lbs | 300 lbs | d2 | s (16 bar) | s (40 bar) | |||
| 1/2″ | 89 | 95,2 | 130 | 32 | 45 | 10 | 10 |
| 3/4″ | 98 | 117,3 | 150 | 32 | 45 | 10 | 10 |
| 1″ | 108 | 123,8 | 160 | 48 | 63 | 10 | 15 |
| 1 1/4″ | 118 | 133,4 | 180 | 48 | 63 | 10 | 15 |
| 1 1/2″ | 127 | 155,6 | 200 | 65 | 80 | 12 | 20 |
| 2″ | 152 | 165,1 | 230 | 80 | 100 | 15 | 25 |
| 2 1/2″ | 178 | 190,5 | 290 | 80 | 100 | 15 | 25 |
| 3″ | 191 | 209,9 | 310 | 100 | 125 | 20 | 30 |
| 4″ | 228* | 254,0 | 350 | 125 | 150 | 25 | 32 |
| 5″ | 254* | 279,4 | 400 | 150 | 175 | 25 | a. A. |
| 6″ | 279 | 317,5 | 480 | 175 | 200 | 30** | a. A. |
| 8″ | 343* | 381,0 | 600 | 175 | 200 | 30** | a. A. |
| 10″ | See Lumistar Model 112-A | ||||||
Variants & options
- Straight-through tubular sight glass (single tube)
- Full-view sight glass (large viewing plate)
- Three-piece serviceable tubular sight glass (replaceable cartridge)
- Reflex / transparent hybrid windows for contrast enhancement
- Illuminated sight glass with integrated LED lighting
- Coatings and special seals for food/pharma applications
Typical applications
Use ANSI straight-through sight glass for process lines in chemical plants, refineries, steam plants, water treatment, food & beverage and OEM process equipment where inline visual verification is required.
Installation & maintenance
- Install using correct flange gaskets and torque bolts evenly to prevent glass point-loading.
- Replace tubes on three-piece assemblies without breaking the main pipeline connection.
- Inspect the glass for scratches, chips, or thermal cracks before pressurizing.
- Follow cleaning guidance — do not use abrasive cleaners on coated surfaces.
Frequently asked questions
- 1. Is this sight glass ANSI compatible?
- Yes. We offer ANSI 150/300/600 flanged versions and can match your flange drilling and facing requirements
- 2. Can I get a replaceable tube variant?
- Yes. Our three-piece designs allow quick cartridge replacement to minimize downtime
- 3. Which glass should I choose for high temperatures?
- Choose quartz or tempered borosilicate depending on your temperature and chemical conditions. Contact us with process details for recommendation.









