F-3 Fixed Integral Flange (Vulcanized and Welded in One Piece)

Fixed / Integral Flanges (Vulcanized / Welded)
I. Key Structural Features
The metal joint connecting the flange to the rubber hose forms a rigid, integral structure through vulcanization (bonding rubber to metal) or welding. This design eliminates sliding clearance, ensuring high connection strength and excellent sealing performance, making it the primary connection method for medium- and high-pressure applications.
II. Material Classification
1. Carbon Steel Integral Flanges: High strength and low cost, suitable for non-corrosive media such as hydraulic systems, general-purpose fluids, and low-pressure steam;
2. Stainless Steel Integral Flanges (304/316): Corrosion-resistant and heat-resistant, suitable for acidic, alkaline, high-temperature, and corrosive environments in chemical, petroleum, marine, food, and pharmaceutical industries;
3. Cast iron integral flanges: Highly brittle, used only in low-pressure, ambient-temperature, non-corrosive applications (rarely used for high-pressure hoses).
III. Primary Functions
1. Enable rigid flange connections between rubber hoses and metal pipes/equipment, withstanding medium-to-high pressure, high temperatures, and vibration loads;
2. The integrated vulcanized/welded structure prevents joint loosening, ensuring long-term stable sealing with no risk of leakage;
3. Transmits axial forces and torque, suitable for industrial applications with severe impact and vibration, such as hydraulic systems and mining;
4. Resists high-temperature and high-pressure fluid media, suitable for harsh transport environments involving high-temperature oil, high-pressure water, and steam.
IV. Typical Applications
1. Hydraulic transmission systems (excavators, loaders, hydraulic power units);
2. Oil drilling and mining conveyance pipelines (high-pressure mud, crude oil, heavy oil);
3. High-temperature steam and high-pressure water jet cleaning equipment;
4. Chemical industry high-pressure medium conveyance (acid and alkali solutions, organic solvents; stainless steel construction);
5. High-pressure hose assemblies for marine vessels and construction machinery.
V. Applicable Operating Conditions
 Pressure: Medium to high pressure (PN16–PN100, or pressure rating ≥2.5 MPa);
 Temperature: High temperature / ambient temperature (-40°C to 300°C, depending on rubber material and metal welding process);
 Media: High-pressure oil, high-temperature steam, acids and alkalis, slurry, crude oil, etc.;
 Environment: Industrial settings with severe vibration, high impact, and frequent reciprocating motion.
VI. Visual Description
1. Overall Structure: A circular flange is rigidly connected to a metal fitting; the fitting is tightly bonded to the rubber hose body via a vulcanized layer, with no moving parts;
2. Installation: The flange aligns directly with the flange of the connected pipe; after tightening the bolts, the sealing surfaces fit tightly together to form a gap-free, rigid seal;
3. Detailed Features: Flange faces are typically raised face (RF), male-female (MFM), or ring joint (RJ) types, paired with metal spiral gaskets or metal ring gaskets. The vulcanized layer at the joint is uniform and full, with no welding cracks or vulcanization defects.
VII. Additional Selection Notes
1. Advantages: High structural strength, reliable sealing, vibration and impact resistance, suitable for harsh operating conditions;
2. Limitations: Difficult to disassemble and reassemble; cannot accommodate thermal expansion and contraction through sliding; requires precise alignment during installation;
3. Compatibility Recommendations: Pair with high-pressure rubber hose assemblies; comply with standards such as GB/T 10747 and HG/T 20592; select media-resistant rubber types such as fluorocarbon rubber or nitrile rubber based on the specific medium.