Single Sphere Rubber Expansion Joint

The Single Sphere Rubber Expansion Joint (also known as flexible single sphere rubber joint or vibration isolator) is a highly elastic pipeline flexible connector. The product consists of a rubber sphere body (inner rubber layer, nylon cord fabric reinforcement, outer rubber layer) combined with loose metal flanges, molded through high-temperature, high-pressure vulcanization. The products strictly comply with GB/T 26121 standards, with multiple quality inspections from raw materials to finished products, featuring high internal density and significant elastic deformation. Sphere materials include NR, NBR, EPDM, CR, FKM, etc., offering resistance to heat, acids, alkalis, corrosion, and oil. Flange materials include Carbon Steel Q235 or Stainless Steel 304/316L.

Two Core Functions: Displacement Compensation + Vibration Damping

The Single Sphere Rubber Expansion Joint serves two main functions during operation:

First, displacement compensation. When pipelines experience thermal expansion/contraction due to temperature changes or displacement due to equipment vibration, the rubber sphere undergoes elastic deformation through its unique curved structure, converting pipeline displacement stress into elastic deformation energy, effectively absorbing axial, lateral and angular displacements and reducing pipeline stress.

Second, vibration damping and noise reduction. Rubber, as a poor conductor, effectively blocks vibration and noise transmission in pipelines, protecting pumps, valves and other equipment from vibration damage while reducing structure-borne noise.

Applications

Widely used in water supply & drainage, circulating water, HVAC, fire protection, papermaking, pharmaceutical, chemical, marine, power and other pipeline systems. Particularly suitable for:

• Pump suction/discharge connections --- absorbing pump vibration to protect downstream equipment
• Pipeline bends --- compensating for installation deviations and thermal displacement
• Fire protection systems --- connecting fire pumps to pipelines, absorbing pressure fluctuations
• Cooling circulating water systems --- thermal power plant feedwater and cooling circulation
• Pipelines with frequent temperature changes --- effectively absorbing repeated thermal displacement

Suitable media include: air, compressed air, water, seawater, hot water, oil, weak acids, weak alkalis, etc.

Material Selection Guide

FAQ

Q1: What is the difference between single sphere and double sphere? How to choose?

A: Single sphere has simpler structure, smaller size and lower cost, suitable for general displacement compensation and vibration damping. Double sphere offers larger compensation and better damping, suitable for large displacement or severe vibration. Single sphere is sufficient for general conditions; Dafugui can assist with selection.

Q2: How to select rubber material based on medium?

A: Water/air → NR; Oil → NBR; Acids/alkalis/outdoor → EPDM; High temperature/corrosive → FKM. Dafugui can provide professional recommendations based on your operating conditions.

Q3: How long does the product last? When to replace?

A: 3-5 years under normal conditions. Replace if cracks, aging, bulging or continuous leakage are found on the sphere surface. Dafugui provides genuine replacement parts.