ASTM A240 S347 Flange is a pipeline/equipment connector. Its core function is to achieve detachable connections between pipelines, pipelines and equipment (such as reaction vessels and heat exchangers), and ensure the sealing performance of the connection parts. HT PIPE supply all different types and scales of flanges. Please feel free to contact us for further product information and pricing.
S347 Flange core performance
Sealing stability: The low deformation characteristics of S347 material ensure that the flange sealing surface (such as protruding RF, full plane FF) adheres to the gasket for a long time, and there is no risk of medium leakage under high temperature (≤ 800 ℃) and medium high pressure (≤ PN40) working conditions.
High temperature resistance: The continuous use temperature can reach 800 ℃, and the short-term tolerance is 900 ℃. It is suitable for connecting high-temperature steam and high-temperature flue gas pipelines (such as boiler main steam pipeline flanges).
Corrosion resistance: It has good resistance to organic acids, nitric acid, phosphoric acid, and chloride containing ion media, and the sealing surface is not easily prone to pitting or pitting due to corrosion, suitable for corrosive environments such as chemical and seawater treatment.
Mechanical strength: Tensile strength at room temperature ≥ 515MPa, hardness ≤ 187HB, able to withstand the pre tightening force and medium pressure during bolt tightening, avoiding deformation of the flange body.
Welding and assembly performance: It can be connected to pipelines through arc welding, argon arc welding, and does not require solution treatment after welding. The machining accuracy of bolt holes is high (aperture tolerance H14), which facilitates precise fitting with bolts and reduces assembly deviations.
Main Structural Types of S347 Flange
|
Structural Type |
Structural Features |
Applicable Pressure Class |
|
Slip-On Flange (SO) |
Short flange neck, pipe is inserted into the flange hole for welding; low cost |
PN1.0-PN16 |
|
Weld-Neck Flange (WN) |
Long flange neck, butt-welded with pipes; high rigidity |
PN10-PN40, Class150-Class600 |
|
Socket-Weld Flange (SW) |
Pipe is inserted into the flange socket for welding, small sealing surface |
PN16-PN40 |
|
Threaded Flange (TH) |
Flange with internal threads, connected to externally threaded pipes without welding |
PN1.0-PN10 |
|
Blind Flange (BL) |
No through hole, used for sealing pipe ends |
PN1.0-PN40 |
S347 Flange Quality Inspection
Appearance inspection: Visually inspect the flange surface for cracks, pores, and inclusions, and the sealing surface for dents.
Dimensional inspection: Use a vernier caliper to measure the diameter and center distance of bolt holes, and use a depth gauge to measure the height of the sealing surface. The deviation must comply with the standard.
Material testing: Use a spectrometer to detect the chromium, nickel, and niobium content on site to ensure that it is S347 material.
Non destructive testing: Ultrasonic testing (UT) is required for welding flanges to identify internal defects in forgings. High pressure flanges (PN ≥ 25) require magnetic particle testing (MT) to inspect the sealing surface and root cracks of the flange neck.
Mechanical performance testing: One flange sample is taken from each batch to test its tensile strength and hardness, which must comply with the requirements of ASTM A182.
Sealing performance testing: Conduct a sample air tightness test (pressure 0.6MPa, holding pressure for 24 hours), with a leakage rate of ≤ 1 × 10 ⁻⁶ Pa · m ³/s.
