Explosive atmosphere sight glass Type 531

borosilicate glassweld-on

The welded flow sight glass type 531 is designed for visual inspection of liquid and gaseous media directly in pipelines. It is available in a wide range of nominal sizes and pressure ratings and can be supplied with multiple glass and sealing options to meet specific process requirements.

Overview

• Welded construction for direct integration into pipeline systems.
• Designed for operating pressures up to 63 barg (dependent on DN and configuration).
• Standard borosilicate glass rated up to 280 °C; with mica protection discs and MAXOS® safety sight glasses up to 300 °C or 320 °C.
• Suitable for both liquid and gaseous media.
• Custom lengths and special constructions available; a range of accessories can be fitted.

Available ranges (from product technical data)

• Nominal sizes (DN): 40, 50, 80, 100, 125, 150, 200, 250, 300, 350, 400
• Nominal pressure (PN): 10, 16, 25, 40, 63
• Temperature options (examples): 80 °C, 130 °C, 150 °C, 175 °C, 180 °C, 200 °C, 280 °C, 300 °C, 320 °C

Options & accessories

• Wiper SGW with PTFE or silicone wiper blade
• LED lighting for Ex and non-Ex areas
• FEP or Halar® coating
• Mica protection discs
• Double glazing version: type 531D
• Special constructions and customer-specific solutions

Dimensions (selection)

• DN → 40 | 50 | 80 | 100 | 125 | 150 | 200 | 250 | 300 | 350 | 400
• BL (face-to-face length mm): 200 | 230 | 310 | 350 | 400 | 480 | 600 | 730 | 850 | 980 | 1100
• D1 (mm): 35 | 45 | 55 | 83 | 107 | 132 | 160 | 160 | 160 | 160 | 160
• AL (mm): 260 | 260 | 340 | 380 | 420 | 470 | 580 | 650 | 700 | 750 | 800
• C (mm): 48.3 | 60.3 | 88.9 | 114.3 | 139.7 | 168.3 | 168.3 | 219.1 | 273 | 355.6 | 406.4
• WT (wall thickness mm): 2.6 | 2.9 | 3.2 | 3.6 | 4.0 | 4.5 | 6.3 | 7.1 | 8.0 | 8.8 | 11.0
• Note: Dimensions correspond to PN 16 where constructively possible; other pressure ratings may affect dimensions. Order confirmation / customer drawing is authoritative for final dimensions.

Technical specifications

• Product type: Flow sight glass, welded ends (type 531)
• Model: Flow sight glass type 531
• Max. operating pressure: up to 63 barg (depending on DN and configuration)
• Nominal sizes: DN 40 – DN 400
• Available PN ratings: PN 10, PN 16, PN 25, PN 40, PN 63
• Standard glass: borosilicate (up to 280 °C)
• High-temperature option: mica protection disc and MAXOS® safety sight glass up to 300 °C or 320 °C
• Sealing: flat seals in many materials (fiber materials, PTFE (Teflon®), NBR, novaphit® MST-XP, KlingerSil® C4400, and other branded seals)
• Media: suitable for liquids and gases
• Accessories: LED lights, FEP coatings, mica discs, sight glass wipers, etc.
• Special features: double glazing option (531D), custom lengths and special constructions available

Certifications & quality

• Typical certifications: TÜV / ISO 9001 (refer to manufacturer for current certificates)
• Conformity note: manufacturer information may reference 2014/68/EU (Annex III) and relevant directives