High-Pressure PN25 DN350 Segmented Flange Rubber Flexible Joint | Custom-to-Drawing Solutions for Compact Pump Rooms with Short Lead Times
Product Overview
This heavy-duty single-sphere DN350 rubber expansion joint is custom-engineered for maximum performance under critical PN25 (2.5 MPa / 25 bar) operating pressures. Drilled strictly to EN 1092-1 / GB specifications with a robust 16-bolt pattern, this high-pressure expansion bellow is purpose-built for the positive-pressure discharge lines of high-head water pumps. It efficiently attenuates severe structural vibrations, lowers acoustic noise, and compensates for axial and lateral pipe movements in high-velocity fluid networks.
Constructed from premium, high-density EPDM rubber, the main elastomer body delivers exceptional thermal stability and ozone-aging resistance. This molded rubber flexible joint features an unlined full-bore interior, completely omitting negative-pressure vacuum rings. This creates a perfectly uniform, smooth inner wall that minimizes hydraulic flow resistance, prevents micro-vortex erosion, and extends operational lifespan under high-velocity positive-pressure flow streams.
To overcome spatial constraints in ultra-compact pump rooms, this unit features customized segmented flanges where the top and bottom edges are precision-machined flat. This flattened geometry prevents clearance interference with pump casing protrusions, low structural steel frames, or adjacent parallel piping systems. Additionally, the unit incorporates an integrated 6-hole limit rod system directly within the flange perimeter, eliminating bulky exterior gusset ears. This arrangement rigidizes the assembly against axial thrust and severe water hammer up to 25 bar, while providing ample wrench clearance to torque down highly recessed pipe bolts. We specialize in custom-to-drawing engineering based on your CAD prints, ensuring premium B2B quality control standards and exceptionally short lead times to avoid installation delays.
Key Features
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- PN25 Severe Pressure Rating: Reinforced single-sphere carcass handles continuous 25-bar working pressures and high hydraulic thrust transients without structural distortion.
- Segmented Anti-Interference Flanges: Top and bottom flattened flange profiles eliminate mechanical clearance issues inside tightly packed pump bays.
- Integrated 6-Rod Restraint: Built-in flange tie-rod holes safely contain full axial hydraulic pressure blowout forces without extending the product’s radial footprint.
- Full-Bore Smooth Flow Passage: Devoid of inner vacuum rings, the smooth interior reduces pressure drops and eliminates high-velocity turbulent scrubbing erosion.
- Premium Thermal EPDM Elastomer: Engineered to withstand continuous hot water exposure and aggressive atmospheric cross-aging without elastomeric hardening.
- EN 1092-1 Compliant 16-Bolt Hole Layout: Symmetrical drilling assures precise bolt circle alignment and optimized gasket face torque seating across heavy metallic flanges.
- Compressed Manufacturing Cycles: Localized heavy-duty tooling configurations enable us to secure short lead times, shipping premium customized parts to match fast-tracked build deadlines.
Applications & Equipment
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- High-Head Water Pump Discharges: Heavy-duty flexible soft connections mounted right at the positive-pressure outlets of high-lift centrifugal water pumps to absorb extreme motor vibration.
- High-Rise District Water Supply: Vibration and expansion-absorbing links serving primary booster pump stations and municipal vertical lift piping manifolds.
- Industrial Cooling Mainlines: Reliable rubber bellow installations on the main distribution headers of high-volume cooling water circulation loops in manufacturing facilities.
- Water treatment Pressure Filters: Structural buffer modules coupling large diameter pipelines to high-pressure water filtration tanks where pipe alignment is constricted.
FAQ
Q: How does the integrated tie-rod design and segmented flange profile protect this DN150/DN350 PN25 rubber expansion joint against severe water hammer in tight spaces?
A: High-head pumping lines operating at PN25 face massive hydraulic blind plate forces during pump startup or sudden valve closure. Standard rubber joints fitted with traditional exterior gusset ear plates create clearance interference inside compact modern pump rooms. Our engineered rubber expansion joint solves these footprint and safety limitations through four targeted technical measures:
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- Earless Zero-Interference Footprint: Traditional tie-rod systems rely on external ears welded to the flange perimeter, which can easily clash with nearby parallel pipes or low sub-floor steel pillars. By milling six limit rod holes directly into the existing flange perimeter, we preserve a clean, compact circular outline that slides effortlessly into tight spaces without sacrificing structural strength.
- Rigid Blowout Containment Up to 25 Bar: A DN350 pipeline under 2.5 MPa exerts massive axial thrust that would rip an unrestrained joint apart. The integrated 6-rod restraint distributes tension uniformly across the entire flange ring, rigidizing the single sphere against high-velocity water hammer and preventing dangerous over-extension.
- Turbulence-Free Full-Bore Longevity: High-pressure discharge flows often reach extreme velocities. If an inner metal vacuum ring were present, the water would crash against the obstruction, generating severe localized turbulence that quickly erodes the EPDM core. Our smooth, unlined interior guarantees a smooth, unrestricted flow profile, maximizing the lifespan of the rubber flexible joint.
- Optimized Tool Clearance with Short Delivery: Standard tight bolt patterns often leave no room for hydraulic wrenches during field installation. Our integrated 6-rod layout leaves ample wrench space to torque down the remaining 16 bolt holes properly. We manufacture these complex, non-standard components exactly from your CAD blueprints under premium quality protocols, delivering completed custom units within short lead times to keep your piping project on schedule.
