Sight Flow Indicators - 881 | Noris Armaturen

NORIS Model 881 – Dual-Sided Flow Indicator with Threaded Connection

The NORIS 881 is a straight dual-sided flow indicator with BSP or NPT threaded connections. It is used for visual inspection of liquids and gases in horizontal or vertical pipelines, ensuring flow direction is maintained during installation.

Technical Specifications

• Connections: BSP G or NPT
• Operating Pressure: 16 / 25 / 40 bar
• Operating Temperature: 150 °C or 280 °C
• Sizes: 1/4" to 2"
• Installation: Horizontal or Vertical
• Options: Spinner, Flap, Observation Light
• Certificates: EN 10204 type 2.2 or 3.1 optional

Materials and Sealing

Body and covers available in GG25 / EN-GJL-250, GS-C25 / 1.0619 / GP240GH, or stainless steel 1.4408. GG25 version limited to 16 bar max pressure. Glasses are borosilicate per DIN 7080 for up to 280 °C or soda-lime per DIN 8902 for up to 150 °C. Standard sealing is graphite, with other materials available after fluid and temperature assessment.

BSP / NPT Selection Point

NPT connection available only in GS-C25 or 1.4408. This is critical for projects with American piping standards, where cast iron execution is not considered available.

Applications

Suitable for process water, auxiliary circuits, gases, condensate, and chemical liquids compatible with construction materials. Spinner or flap is selected when fluid is clear or when more distinct flow presence indication is required.

Difference from NORIS 880

The 880 is a flanged DIN flow indicator, while the 881 uses BSP or NPT threaded connections. The 881 is mainly chosen for smaller diameters and auxiliary lines where flanged connection is not necessary.

FAQ

Does it accept an actuator?
No. It is a passive flow indicator. Options concern visual indication or lighting.

What is specified in the order?
Thread BSP or NPT, size, pressure, temperature, body material, glass type, sealing, and need for spinner, flap, or lighting.