Rubber Expansion Joint

Rubber expansion joint, also called rubber bellows, flexible rubber connectors, or vibration absorber couplings, are widely used components in piping systems. They are designed to absorb thermal expansion, mechanical vibration, and pipeline displacement in industrial, civil, and HVAC installations.

This single-sphere rubber joint is typically made from high-quality EPDM, NBR, or neoprene rubber, reinforced with nylon cords and steel rings. It offers outstanding flexibility, pressure resistance, corrosion resistance, and long service life.

ZHENGDA rubber joints are compatible with ANSI, DIN, and JIS flange standards, making them suitable for HVAC systems, water treatment plants, chemical pipelines, pump systems, and mechanical equipment connections. Whether for new construction or system upgrades, our rubber expansion joints help reduce noise, absorb vibration, and provide stable sealing under various working conditions.

Key Features

• Compact single-sphere structure for space-saving installation

•Effectively absorbs vibration and noise in piping systems

•Compensates for axial, lateral, and angular movements

•Made from EPDM, NBR, or Neoprene rubber with nylon and steel reinforcement

•High sealing performance under low to medium pressure conditions

•Corrosion-resistant, aging-resistant, and long service life

•Compatible with ANSI, DIN, and JIS standard flanges

•Widely used in HVAC, water supply, chemical, and mechanical systems

Technical Specifications

Nominal Diameter (DN)	Inch	Length (L) mm	Flange Thickness (b) mm	Bolt Qty (n)	Bolt Hole Dia. mm	Bolt Circle Dia. (D1) mm	Axial Extension mm	Lateral Displacement mm	Angular Deflection (°)
DN32	1.25”	95	16	4	18	100	6	9	9
DN40	1.5”	95	18	4	18	110	6	10	9
DN50	2”	105	18	4	18	125	7	10	10
DN65	2.5”	115	20	4	18	145	7	13	11
DN80	3”	135	20	4	18	160	8	15	12
DN100	4”	150	22	8	18	180	10	19	13
DN125	5”	165	24	8	18	210	12	19	13
DN150	6”	180	24	8	23	240	12	20	14
DN200	8”	210	24	8	23	295	16	25	22
DN250	10”	230	26	12	23	350	16	25	22
DN300	12”	245	28	12	23	400	16	25	22
DN350	14”	255	28	16	23	460	16	25	22
DN400	16”	255	30	16	25	515	16	25	22
DN450	18”	255	30	20	25	565	16	25	22
DN500	20”	255	32	20	25	620	16	25	22
DN600	24”	260	36	20	30	725	16	25	22
DN700	28”	260	36	24	30	840	16	25	22
DN800	32”	260	38	24	34	950	16	25	22
DN900	36”	260	42	28	34	1050	16	25	22
DN1000	40”	260	44	28	34	1160	18	26	24
DN1200	48”	260	48	32	41	1380	18	26	24
DN1400	56”	350	44	36	34	1560	20	28	26
DN1600	64”	350	46	40	34	1760	25	35	30
DN1800	72”	350	52	44	41	1970	25	35	30
DN2000	80”	420	54	48	48	2180	25	35	30
DN2200	88”	580	40	52	48	2390	25	35	30
DN2400	96”	610	41	56	48	2600	25	35	30
DN2600	104”	650	42	60	54	2810	25	35	30
DN2800	112”	680	45	64	54	3020	25	35	30
DN3000	120”	680	50	68	54	3220	25	35	30

Notes

Customization available upon request with specific drawings or specifications; flanges are based on the “National General Water Supply and Drainage Standard Atlas,” others follow HG/T2289-92.
For DN350-600(2) models, working pressure is 1.6MPa; for DN32-400(3) models, working pressure is 2.5MPa.
For DN700-DN200 models, working pressure is 1.0MPa; for DN1400, working pressure is 0.6MPa; for DN1600-DN1800, working pressure is 0.4MPa, flanges are selected according to 0.6MPa; for DN2000, working pressure is 0.25MPa, flanges are selected according to 0.6MPa pressure.
For high-rise water supply, products above DN200 must have fixed supports or brackets; otherwise, anti-pullout devices should be installed.

Project	Unit	JGD-1	JGD-2	JGD-3
Model	–	JGD-1	JGD-2	JGD-3
Working Pressure	MPa (kgf/cm²)	1.0 (10)	1.6 (16)	2.5 (25)
Burst Pressure	MPa (kgf/cm²)	2.0 (20)	3.0 (30)	4.5 (45)
Vacuum Resistance	KPa (mmHg)	53.3 (400)	86.7 (650)	100 (750)
Operating Temperature	°C	-15 ~ 115°C (Special: -30 ~ 250°C)	–	–
Applicable Media	–	Air, Compressed Air, Water, Seawater, Hot Water, Oil, Acid, Alkali, etc.

Material	Temperature Range (°C)	Oil Resistance	Acid & Alkali Resistance	Elasticity	Abrasion Resistance	Typical Applications

EPDM

-40 ~ 120

Poor

Excellent

Medium

Water, Steam, Air

NR (Natural Rubber)

-30 ~ 80

Poor

Medium

Excellent

Industrial Water, Air

NBR

-20 ~ 100

Excellent

Medium

Good

Oil, Lubrication Systems

Neoprene

-35 ~ 100

Good

Medium

Good

Seawater, Mild Chemicals

Silicone

-60 ~ 200

Poor

Good

Low

Food Grade, Medical

FKM (Viton)

-20 ~ 250

Excellent

Medium

Excellent

Chemical, High Temp Oil

Butyl (IIR)

-40 ~ 120

Poor

Good

Excellent

Medium

Gas, Acidic Gases

1.Inspection Before Installation

•Check whether the rubber joint is damaged, aged, or defective.

•Confirm the model, pressure rating, and flange size match the system requirements.

2.Installation Environment

•Avoid installation under direct sunlight, ozone, or in environments with high temperature or strong corrosive chemicals.

•If outdoor installation is necessary, use UV-protective shields or covers.

3.Installation Instructions

•Align the rubber joint with the center of the pipe flanges. Avoid pulling or twisting during installation.

•Tighten bolts crosswise and evenly to avoid uneven force or deformation.

•Use proper washers and gaskets.

4.Precautions

•Ensure the pipeline is properly fixed; rubber joints are not designed to bear the full weight.

•Do not over-extend, over-compress, or apply excessive torsion to the joint.

•Allow for movement as specified (axial, lateral, angular) within rated limits.

•Install limit rods or anti-pull devices if the pipe system lacks sufficient fixation.

5.Working Pressure & Temperature

•Observe the rated pressure and temperature range during operation.

•Standard range: -15°C to +115°C (or as specified).

6.Routine Inspection & Maintenance

•Inspect every 6–12 months for signs of aging, damage, or leakage.

•Replace if any abnormalities are found.

1. Inspection Before Installation

•Check whether the rubber joint is damaged, aged, or defective.

•Confirm the model, pressure rating, and flange size match the system requirements.

2.Installation Environment

•Avoid installation under direct sunlight, ozone, or in environments with high temperature or strong corrosive chemicals.

•If outdoor installation is necessary, use UV-protective shields or covers.

3.Installation Instructions

•Align the rubber joint with the center of the pipe flanges. Avoid pulling or twisting during installation.

•Tighten bolts crosswise and evenly to avoid uneven force or deformation.

•Use proper washers and gaskets.

4.Precautions

•Ensure the pipeline is properly fixed; rubber joints are not designed to bear the full weight.

•Do not over-extend, over-compress, or apply excessive torsion to the joint.

•Allow for movement as specified (axial, lateral, angular) within rated limits.

•Install limit rods or anti-pull devices if the pipe system lacks sufficient fixation.

5.Working Pressure & Temperature

•Observe the rated pressure and temperature range during operation.

•Standard range: -15°C to +115°C (or as specified).

6.Routine Inspection & Maintenance

•Inspect every 6–12 months for signs of aging, damage, or leakage.

•Replace if any abnormalities are found.

Why Choose Our Rubber Expansion Joints

•Proven Quality

Our products are made from high-quality rubber and steel materials, tested for durability and long-term service under harsh industrial conditions.

•Global Standards

Manufactured in compliance with DIN, ANSI, JIS standards. Compatible with global piping systems.

•Custom Solutions

Available in multiple sizes and materials (EPDM, NBR, FKM) to meet various media and working conditions.

•Factory Direct Supply

Competitive pricing with fast delivery from our own manufacturing facility.

•Trusted by Clients Worldwide

Exported to Southeast Asia, the Middle East, Europe, and other regions with excellent client satisfaction.

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Rubber Expansion Joint