Single Sphere Flanged Joint

Product Overview

The Single Sphere Flanged Joint is a single-arch rubber expansion joint designed to absorb mechanical movement, isolate vibration, and reduce noise transmission in piping systems. Its compact, spherical arch profile provides excellent flexibility while maintaining structural integrity under pressure, making it an essential component in a wide range of industrial and commercial installations.

Construction and Materials

The joint features a single spherical rubber arch reinforced with multiple layers of high-tensile fabric plies and, where required, embedded steel wire rings for additional pressure resistance. The arch is available in three primary elastomer compounds to suit different media and operating conditions:

• EPDM (Ethylene Propylene Diene Monomer) – ideal for hot water, steam, and outdoor applications with excellent ozone and UV resistance.
• NBR (Nitrile Butadiene Rubber) – suited for petroleum-based fluids, oils, and fuels due to its superior hydrocarbon resistance.
• Neoprene (Chloroprene Rubber) – a versatile compound offering balanced resistance to weathering, ozone, and moderate chemicals.

The flanged ends are manufactured from carbon steel or ductile iron, drilled to PN10 or PN16 standards, and are compatible with standard mating flanges. Stainless steel flanges are available on request for corrosive environments.

Pressure Ratings

Single Sphere Flanged Joints are rated for working pressures between 6 and 16 bar, conforming to PN10 and PN16 flange pressure classes. The burst pressure is typically four times the working pressure, providing a generous safety margin. Vacuum service is also supported, with full vacuum ratings available for selected sizes.

Size Range

The product is available in nominal diameters from DN40 to DN1200, covering the full spectrum of pipeline sizes encountered in building services, utilities, and heavy industry. Custom sizes outside this range can be manufactured to order.

Movement Capabilities

The spherical arch geometry allows the joint to accommodate three types of pipe movement simultaneously:

• Axial movement – compression and extension along the pipe axis (typically ±20 mm).
• Lateral movement – transverse offset perpendicular to the pipe axis (typically ±15 mm).
• Angular movement – rotational deflection about the joint centre (typically ±15°).

These movement values are size-dependent; refer to the product datasheet for precise figures at each nominal diameter.

Typical Applications

Single Sphere Flanged Joints are widely used across multiple industries and system types:

• HVAC systems – chilled water, heating water, and condenser water circuits in commercial buildings.
• Water treatment plants – raw water intake, filtration, and distribution pipelines.
• Industrial pipelines – chemical processing, power generation, and marine applications.
• Pump connections – isolating pump vibration from the surrounding pipework to protect equipment and reduce noise.

Installation Notes

Install the joint in a relaxed, neutral position without pre-compression or pre-extension. Ensure the mating flanges are parallel and aligned before tightening bolts in a cross-pattern sequence to the specified torque. Control rods or limit bolts should be fitted where the system pressure would otherwise cause excessive elongation. The joint should not be used as a pipe support; adequate pipe guides and anchors must be provided in accordance with the manufacturer's installation guide.