Direct-from-factory engineered flange components manufactured under ISO 9001 and PED 2014/68/EU quality control standards.
An authoritative evaluation of slip-on (SO) flange kinematics, stress redistribution, and structural integrity across energy, chemical, and marine infrastructure.
Slip-on flanges (ASME B16.5 / EN 1092-1 Type 12) slip over the pipe end and are secured via two fillet welds: one executed internally at the flange face bore edge and one externally at the flange hub shoulder. This design reduces alignment complexity during field erection compared to butt-weld profiles.
Calculated under ASME Section VIII Division 1 guidelines, the fatigue resistance of a double-welded slip-on flange is approximately 1/3 that of a corresponding weld neck (WN) flange under cyclic bending moments. Consequently, SO flanges excel in low-to-medium pressure ratings (Class 150 to Class 600, PN6–PN40).
Our forged steel slip-on flanges are CNC-machined to exacting tolerances. Bore diameters adhere strictly to ASTM A105 and ASME B16.5 (+0.8mm/-0.0mm), preventing excessive pipe wall play while ensuring optimal capillary action during inner fillet welding.
To prevent gasket seat damage during field welding, pipe fitters must recess the pipe end back from the flange face by a distance equal to the pipe wall thickness plus 1.6 mm (1/16 in). This prevents heat distortion of the raised face (RF) or flat face (FF) serrated grooves (125–250 µin AARH finish).
Quantitative assessment helping procurement engineers select the optimal joint design based on fluid dynamics, thermal stress, and overall total cost of ownership (TCO).
| Flange Type | Primary Joint Weld Type | Pressure Class Range | Relative Fabrication Cost | Vibration & Fatigue Resistance | Primary Industrial Application |
|---|---|---|---|---|---|
| Steel Slip-On (SO) Flange | Double Fillet Weld (Hub & Bore) | Class 150 – Class 600 / PN6–PN40 | Low (Easy alignment, no bevel cutting) | Moderate (33% of WN rating) | Petrochemical storage, HVAC, municipal water, low-pressure process lines. |
| Weld Neck (WN) Flange | Full Penetration Butt Weld | Class 150 – Class 2500 / PN6–PN400 | High (Requires pipe end bevel preparation) | Exceptional (High fatigue strength) | High-pressure oil & gas, steam headers, subsea pipelines, sour gas (NACE). |
| Blind (BL) Flange | Bolted Connection (Solid Disc) | Class 150 – Class 2500 / PN6–PN400 | Moderate (Material mass dependent) | High (Designed for dead-end pressure) | Pressure vessel inspection ports, pipeline end isolation, hydro-test blanking. |
| Lap Joint (LJ) Flange | Loose fit over Stub End | Class 150 – Class 300 / PN10–PN40 | Moderate-High (Requires matching Stub End) | Low-Moderate | Corrosive fluid systems, frequent maintenance/dismantling lines. |
Located in China's famous "Hometown of Forging" — Dingxiang County, Shanxi — YUXIN combines 33+ years of metallurgical heritage with state-of-the-art automated CNC manufacturing.
Being based in Zhuangli Industrial Zone gives YUXIN direct access to top-tier steel mills (Taiyuan Iron & Steel, Baosteel). We control the complete process in-house: raw billet heating, closed-die forging, hydraulic ring rolling, normalising/annealing, CNC machining, and non-destructive testing (NDT).
YUXIN is not a trading broker; we are a verified manufacturing mill holding ISO 9001:2015 assessed by TÜV CERT, European Pressure Equipment Directive (PED 2014/68/EU), AD 2000-Merkblatt W0, VdTÜV 350/399-3, and Special Equipment Manufacturing Licensing (TS Class A).
Through automated high-speed forging presses and multi-spindle CNC lathes, we achieve minimal material waste and energy optimization. This enables us to offer tier-1 quality at highly competitive factory-direct pricing for global project tenders and distributor stock replenishment.
How YUXIN customizes steel slip-on flanges and forged rings to meet complex technical standards across diverse international industries.
For processing hydrocarbons containing hydrogen sulfide ($H_2S$), YUXIN supplies ASTM A105N and ASTM A350 LF2 slip-on flanges compliant with NACE MR0175 / ISO 15156. Hardness levels are strictly kept below 22 HRC to eliminate stress corrosion cracking risks.
Shipyard contractors demand high salt-spray corrosion resistance. We produce stainless steel (ASTM A182 F304L/F316L) and Duplex (F51/F53) slip-on flanges certified under classification society standards, complete with protective anti-corrosion coatings or yellow varnish.
Integrating slip-on flanges with precision CNC-drilled tube sheets and expansion joint flanges for thermal power plants and LNG vaporization loops. Bores are verified with 3D coordinate measuring machines (CMM) for exact pitch circle alignment.
How technological advancements and environmental regulations are shaping the next decade of industrial flange manufacturing.
The industry is rapidly shifting away from manual lathe turnings to fully automated robotic CNC cells. YUXIN integrates automated ultrasonic flaw detection (UT) and magnetic particle testing (MT) directly into the machining line, ensuring zero internal void defects before shipment.
Global EPC contractors increasingly require Carbon Footprint Audits for steel products. YUXIN has converted natural gas reheating furnaces to clean energy electric induction systems, reducing carbon intensity per ton of forged steel by up to 28%.
As green hydrogen projects expand across Europe and North America, flanges require ultra-low permeation seating surfaces and specialized low-alloy forging chemistry to prevent hydrogen embrittlement in high-pressure transport pipelines.
Comprehensive inventory covering tube sheets, weld neck, socket weld, plain, and custom engineered forged products.
In-depth expert answers covering manufacturing standards, non-destructive testing, material certification, and logistics.
