NB/T47017 Pressure Vessel Sight Glass
Industrial NB/T47017-2011 standard sight glass for pressure vessels. Available in welded (Type A) or flanged (Type B) connections. Supports pressures up to 70MPa.
Description
NB/T47017 Pressure Vessel Sight Glass | High-Pressure Observation Ports
The NB/T47017 Pressure Vessel Sight Glass represents the modern standard for industrial process observation. Released by the National Energy Administration, this specification unifies legacy standards (such as HGJ51 and HG/T21575) into a single, robust design suitable for the most demanding environments.
Engineers rely on this solution for safe visual monitoring of reactors, storage tanks, and boilers where high pressure or corrosive media are present. Lumiglas manufactures these units to strictly adhere to the NB/T47017-2011 protocol.
Connection Types & Structural Design
Our NB/T47017 series offers two primary installation methods to match your vessel’s fabrication requirements:

(For permanent integration)

(Paired with container flange)
Technical Specifications
Designed for versatility, the Lumiglas NB/T47017 sight glass supports a wide range of materials and pressures.
| Feature | Specification Details |
|---|---|
| Standard Compliance | NB/T47017-2011 (Replaces HGJ51, HG/T21575, HG/T21505) |
| Pressure Rating | Standard: 0.6 MPa – 2.5 MPa Custom High-Pressure: Up to 70 MPa |
| Body Materials | Carbon Steel (Q235, Q345R) Stainless Steel (304, 304L, 316, 316L) Duplex Steel (2205, 2507) |
| Available Sizes | DN50, DN80, DN100, DN125, DN150, DN200 |
| Mounting Options | Type A: Direct Welding (Weld-on pad) Type B: Flange Connection (Clamped) |
| Accessories | Rumi Sprinklers (Wipers), Integrated Spotlights |
| Note: Final dimensions depend on pressure rating. Please verify with technical drawings. | |
Advanced Features & Accessories
To enhance operational safety and visibility, we offer integrated accessories compatible with the NB/T47017 housing:
- Rumi Sprinklers (Cleaning Device): A specialized spray nozzle (Material: 1.4571 / PTFE) installed within the assembly. It allows operators to jet-clean the inner side of the glass without opening the vessel, crucial for sticky or crystallizing media.
- Integrated Spotlights: Dedicated mounting holes allow for the installation of explosion-proof luminaires to illuminate the vessel interior.
- Wiper Systems: Mechanical wipers available for manual cleaning of the glass surface.
Frequently Asked Questions (FAQ)
Q: What is the difference between Type A and Type B?
A: Type A is welded directly to the container shell or head, making it a permanent part of the vessel structure. Type B uses a mating flange and bolts (clamping), allowing for easier removal and maintenance of the entire unit.
Q: Can this sight glass handle super-duplex materials?
A: Yes. We manufacture these units in Duplex 2205 and 2507 stainless steel for environments requiring superior corrosion resistance against chlorides.
Technical Documentation
Download the complete data sheet including dimensional drawings, bolt sizes, and installation guides.





