Sight glass for industrial applications Type 394

for vesselsmonitoringstainless steel

The screwed circular sight glass Type 394 is a female‑threaded tank sight glass for visual monitoring of liquid and gaseous media. Available in multiple nominal sizes and pressure ratings, it can be equipped with protective coatings and a wide choice of sealing materials to match industrial applications.

Materials & glass

• Housing: stainless steel 1.4571 (316Ti)
• Standard sight glass: borosilicate glass to DIN 7080 (other glass types on request)
• Protective/coating options: FEP or Halar®; optional mica protection disc for increased temperature/steam resistance

Connection, sizes & pressure ratings

• Connection type: female thread (internal thread) for screwing on
• Nominal sizes (NPS): ½", 1", 1½", 2"
• Nominal pressure (PN): 16, 40, 63, 100, 160

Temperature & media

• Available temperature ratings (examples/options): 80°C, 130°C, 150°C, 175°C, 180°C, 200°C, 280°C, 300°C, 320°C, 400°C
• Suitable for liquid and gaseous media

Seals, options & accessories

• Sealing: flat gaskets from an extensive range (>50 materials) including fiber materials, PTFE (Teflon®), NBR, novaphit® MST-XP, KlingerSil® C4400 and other branded seals
• Options: wiper SGW (PTFE or silicone blade), FEP or Halar® coating, mica protection, custom designs
• Typical accessories: FEP protective screen/coating, round mica discs, sight glass wiper

Dimensions (excerpt)

• Table header: PN | G (NPS) | Da [mm] | Di [mm] | L [mm] | Weight [kg]
• PN 16 — ½" — 70 — 15 — 20 — 0.8
• PN 16 — 1" — 95 — 25 — 20 — 1.5
• PN 16 — 1½" — 110 — 40 — 20 — 2.2
• PN 16 — 2" — 110 — 40 — 20 — 2.1
• PN 40 — ½" — 70 — 15 — 20 — 0.8
• PN 40 — 1" — 95 — 25 — 20 — 1.5
• PN 40 — 1½" — 110 — 40 — 20 — 2.2
• PN 40 — 2" — 110 — 40 — 20 — 2.2
• PN 63 — ½" — 95 — 15 — 20 — 0.8
• PN 63 — 1" — 95 — 25 — 20 — 1.5
• PN 63 — 1½" / 2" — like PN 100 (see table)
• PN 100 — ½" — 70 — 15 — 20 — 0.8
• PN 100 — 1" — 95 — 25 — 20 — 1.5
• PN 100 — 1½" — 110 — 40 — 20 — 2.2
• PN 100 — 2" — 110 — 40 — 20 — 2.2
• PN 160 — ½" — 70 — 15 — 20 — 0.8
• PN 160 — 1" — 95 — 25 — 20 — 1.8
• PN 160 — 1½" — 110 — 40 — 20 — 2.6
• PN 160 — 2" — 110 — 40 — 20 — 2.7
• Other sizes and pressure ratings available on request
• Installation: via hook wrenches as for DIN 11851

Quick overview / key points

• Max. nominal pressure: up to PN 160
• Temperature resistance: options available up to 280°C (higher-temperature glass or protections on request)
• Suitable for liquid and gaseous media
• Nominal sizes: ½" – 2"
• Custom designs and many sealing material options (>50)

Characteristics / technical specifications

• Model: Type 394 (screwed circular sight glass fitting with female thread)
• Brand: ACI Industriearmaturen
• Housing material: stainless steel 1.4571 (316Ti)
• Standard glass: borosilicate glass DIN 7080 (other glass on request)
• Seals: flat gaskets from extensive material range (PTFE, NBR, novaphit® MST-XP, KlingerSil® C4400, fiber, etc.)
• Nominal pressure: PN 16 / 40 / 63 / 100 / 160
• Nominal sizes (NPS): ½", 1", 1½", 2"
• Typical weights and dimensions: see dimensions list above (Da, Di, L, weight per PN/size)
• Options: SGW wiper (PTFE/silicone), FEP/Halar® coating, mica protection, custom designs