Description
Product Description:
This is a steel spectacle blind complying with ASME B16.48 standard, also known as figure-8 blind or spade blind. It consists of a solid blind end and a concentric ring (throttling ring or open end plate) connected by a shank, featuring a figure-8 appearance. It is applied in pipeline systems where frequent switching between isolation and flow-through states is required.
Specifications:
- Nominal Size: 2" (DN50)
- Pressure Class: Class 150
- Face Type: FF (Flat Face)
- Material: A105 (Carbon Steel Forging)
Raw Materials: The main body is made of A105 carbon steel forging to guarantee overall structural strength and reliability. The blind end and throttling ring end are integrally forged or welded and then fully machined to ensure concentricity and flatness of sealing faces.
Production Process: Forging blank cutting → preliminary figure-8 forging → normalizing heat treatment → rough shaping machining → precision finishing of sealing faces on blind end and throttling end respectively (high flatness required for FF faces) → shank machining → bolt hole drilling (bolt holes on both ends shall be aligned) → deburring and edge chamfering → surface treatment (sandblasting and painting) → dimensional inspection (focus on parallelism of both sealing faces, bolt hole alignment and thickness) → pressure testing (not required conventionally but available on request) → marking (clearly labeling BLIND, THROTTLE or OPEN ends) → packaging.
Application Fields: Widely used in oil refineries, chemical plants, petrochemical enterprises, natural gas processing plants and other occasions requiring regular isolation of equipment such as pumps, valves and filters for maintenance without complete pipeline disconnection. The state between isolation and flow can be switched rapidly by rotating the shank.
Temperature and Pressure Resistance: Its temperature and pressure resistance performance is consistent with ASME B16.5 blinds or flanges of the same material and pressure class. For A105 material, Class 150, FF face, the rated pressure is approximately 19.6 bar (285 psi) within the temperature range of -29°C to 38°C. Flat face flanges are generally adopted for low-pressure applications and shall be matched with full-face gaskets.
Advantages of Hebei Hexin Pipe Fitting Co., Ltd.:
1. Special Product Expertise: Rich mature experience in manufacturing special pipe fittings including spectacle blinds, spade blinds and paddle spacers.
2. Precision Control: Capable of accurately controlling the relative positions of blind end and throttling end as well as sealing face machining to ensure aligned bolt holes during installation.
3. Distinct Marking: Permanent markings are adopted to clearly distinguish blind end and open end, avoiding on-site misoperation.
4. Custom Shank Design: Shanks with customized lengths and shapes can be provided according to customer requirements for convenient operation.
5. Supporting Services: Supplying matched gaskets, bolts and nuts as well as installation guidance.
Examples of Production Size Range:
- Standards: ASME B16.48, MSS SP-44, API 6A (for wellhead equipment)
- Nominal Size: 1/2" up to 24" and larger
- Pressure Classes: Class 150, 300, 600, 900, 1500, 2500
- Materials: A105, F304, F316, F11, F22, duplex steel and other materials
- Face Types: RF, FF, RTJ
- Operation Modes: Manual operating shanks, gear operating mechanisms, hydraulic actuator connectors, etc.
