Product Introduction

The Flexible Rubber Joint, commonly referred to as a Rubber Joint or Rubber Flexible Connector, is composed of a fabric-reinforced rubber element combined with a flat union joint, a sleeve metal flange, or a threaded pipe flange. It is used in piping systems for vibration isolation, noise reduction, and displacement compensation. It is a type of pipeline joint characterized by high elasticity, excellent airtightness, resistance to media, and weather resistance.

National Standards：GB/T 26121-2010 ,HG/T2289-2000

Nominal Diameter：DN40-DN3000

Detailed Explanation：Also known as Vibration Isolator, Flexible Joint, Rubber Flexible Connection, or Pipe Shock Absorber. It solves issues like misalignment, axial expansion/contraction, and eccentricity in various pipelines. Commonly used in civil building water supply and drainage projects, connections for fire protection network pump house units, sewage treatment pipeline connections, transport of high-pressure gas/liquid chemical media, petroleum, ships, etc. It is one of the most widely used rubber joints in pipeline fittings worldwide. Advantages include reducing pipeline noise, good sealing performance, light weight, easy installation and maintenance, and long service life.

Manufacturing Process：Vulcanization technology transforms the linear molecular structure of plastic rubber into a three-dimensional network structure. The inner rubber layer, middle layer reinforced with SNT series Nylon 66 ultra-high-strength industrial cord fabric, and the outer rubber layer of the composite rubber spherical body are vulcanized using the injection molding method. It is assembled with cast iron or forged metal flanges.

By Shape：Concentric Equal Diameter, Concentric Reducing, Eccentric Reducing.

By Structure：Single Sphere, Double Sphere, Elbow Sphere.

By Connection Type：Flange Connection, Threaded Connection, Threaded Pipe Flange Connection.

By Working Pressure：Seven pressure ratings: 0.25MPa, 0.6MPa, 1.0MPa, 1.6MPa, 2.5MPa, 4.0MPa, 6.4MPa.

Performance Characteristics

1、Small size, light weight, good elasticity, easy installation and maintenance.

2、Allows lateral, axial, and angular displacement during installation, not restricted by pipeline misalignment or non-parallel flanges.

3、Reduces structure-borne noise transmission during operation and has strong vibration absorption capability.

Application Scope

Due to its excellent comprehensive performance, the flexible rubber joint is widely used in fundamental projects across chemical industry, construction, water supply, drainage, petroleum, light/heavy industry, refrigeration, sanitation, plumbing, fire protection, power, etc.

Usage Instructions

When used in high-rise water supply systems, the pipeline must have fixed supports or brackets. Otherwise, an anti-dislodgment device must be installed. The force capacity of the fixed support or bracket must be greater than the axial force; otherwise, an anti-dislodgment device must also be installed. For specific media, use: Oil-resistant rubber joint, High-temperature resistant rubber joint, Acid/Alkali resistant rubber joint, Wear-resistant rubber joint, Seawater resistant rubber joint, Corrosion resistant rubber joint.

Technical Specifications

Item / Model	JGD-1	JGD-2	JGD-3
Working Pressure MPa( kgf/cm 2 )	1.0（10 ）	1.6 （ 16 ）	2.5 （ 25 ）
Burst Pressure MPa( kgf/cm 2 )	2.0 （ 20 ）	3.0 （ 30 ）	4.5 （ 45 ）
Vacuum Degree KPa(mm/Hg)	53.3 （ 400 ）	86.7 （ 650 ）	100 （ 750 ）
Applicable Temperature ℃	-15 ℃～ 60 ℃ Special models available for  -30 ℃ ～ 90 ℃
Applicable Media	Air, Compressed Air, Water, Sea Water, Hot Water, Oil, Acid, Alkali, etc.

Installation Method

1、Must be installed in its natural state, avoid artificial deformation. Installation beyond the displacement limit is strictly prohibited.

2、When installed near pump outlets, at pipe bends, under high pressure, or suspended in high-rises, the pipeline must have fixed supports/brackets (force capacity > axial force), otherwise install an anti-dislodgment limit device.

3、For flange connection, ensure the reinforcement rings (containing steel wire rope) at both ends of the sphere fully engage the flange groove. First tighten the symmetrical bolts (6 or 4) to ensure the sphere is fully seated.

4、When connecting to pipeline flanges, bolt threads should extend towards the pipeline flange end. Tighten all bolts symmetrically and evenly. In harsh conditions, add spring washers besides flat washers to prevent loosening.

5、When used near pump outlets or under frequent start/stop conditions, add limit devices at both flanges to reduce excessive stretching/compression effects.

6、For large diameter installation, weld a short pipe section to one flange for ease and reduced labor. First connect the rubber joint, short pipe, and the other pipeline end, then weld the short pipe to the long pipe.

7、To prevent radial deviation from short pipe welding deformation, temporarily weld the pipeline flanges at both ends using round steel etc. before welding, making the joint area rigid. Remove temporary welds after welding.

8、When temporarily welding metal connectors, cover the joint rubber to protect it and avoid welding burns on the sphere.

Installation Notes - Key Summary

1、High-rise water supply: Fixed brackets are mandatory; otherwise, install anti-dislodgment device. Support/bracket force capacity must exceed axial force.

2、Select working pressure (0.25MPa, 1.0MPa, 1.6MPa, 2.5MPa, 4.0MPa) based on pipeline requirements. Refer to the "Flange Dimension Table" for connection sizes.

Engineering Standards

"Flexible Rubber Joint" GB/T26121-2010, CJ/T 208-2005, Ministry of Chemical Industry HG/T2289-2000 (Equivalent to ISO 4633, BS EN 14810, MSS-SP-117)

Design and Selection Key Points

1) Using flanges of other standards or non-standard designs requires a separate agreement, specifying the standard or providing drawings and relevant data. The manufacturer can produce custom units.

2) Number of flange bolts, bolt hole diameter, and bolt hole circle diameter follow GB9113. (Equivalent to ASME B16.5, EN 1092-1).

3) When ordering rubber joints, users must specify relevant elements: working pressure, applicable media, temperature, connection type, and the working environment conditions: presence of strong light, heat sources, ozone, sparks, and frequent contact with sharp objects.

 

The Flexible Rubber Joint, commonly referred to as a Rubber Joint or Rubber Flexible Connector, is composed of a fabric-reinforced rubber element combined with a flat union joint, a sleeve metal flange, or a threaded pipe flange.