ASME B16.5 Class 150 blind flange is an important component of low-pressure piping systems, and its design, manufacturing, and installation must strictly comply with standard requirements. Through reasonable material selection, precise structural design, standardized manufacturing processes, and scientific installation and maintenance, it can ensure long-term safe operation in industries such as petrochemicals, water treatment, food and medicine.
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ASME B16.5 Class 150 blind flange Nominal size range
Small size (NPS 1/2-NPS 2): mainly used for low-pressure instrument pipelines and small equipment interfaces.
Medium size (NPS 3-NPS 12): widely used for conventional end closure in industrial pipeline systems.
Large size (NPS 14-NPS 24): commonly used as maintenance openings for large equipment such as storage tanks and reactors.
ASME B16.5 Class 150 blind flange Sealing surface type
RF (RF): The most commonly used type, with a sealing surface height of 1.6mm (small size) to 3.2mm (large size), requiring soft gaskets such as asbestos rubber gaskets and graphite composite gaskets, suitable for low pressure and non strong corrosion conditions.
Full Flat (FF): The sealing surface is flush with the flange surface, without protrusions, suitable for scenarios that require frequent disassembly or hygiene requirements (such as food and medicine), and needs to be paired with thin gaskets.
Concave convex surface (MFM): The blind flange side is concave, and the mating flange side is convex. The sealing surface accuracy requirement is high (surface roughness Ra ≤ 3.2 μ m), suitable for working conditions with medium and low pressure and high sealing requirements, and can prevent gasket displacement.
Mortise and tenon surface (TG): The blind flange side is the groove surface, and the mating flange side is the mortise and tenon surface. The gasket is embedded in the groove, suitable for flammable, explosive or toxic media, and can avoid medium leakage and safety accidents.
ASME B16.5 Class 150 blind flange Surface treatment
Carbon steel flange: anti-corrosion treatment is required, commonly using hot-dip galvanizing (zinc layer thickness ≥ 85 μ m) and painting (epoxy zinc rich paint, dry film thickness ≥ 60 μ m) to avoid rusting.
Stainless steel flanges: usually treated with acid pickling and passivation (soaking in nitric acid+hydrofluoric acid solution) to remove surface oxide scale, form a passivation film, and improve corrosion resistance.
Alloy steel flange: According to the working conditions, it can be chrome plated (for wear-resistant working conditions) or coated with anti-corrosion coating (for corrosive working conditions). After surface treatment, adhesion should be tested (grid test, adhesion level ≥ 1).
ASME B16.5 Class 150 blind flange dimensions
