Joint

Pipe Expansion Joints & Dismantling Joints Manufacturer

We manufacture flexible rubber expansion joints, double-flanged limit expansion joints, and metallic bellows compensators engineered for thermal expansion, pipeline misalignment, and pump vibration isolation. Production covers nominal sizes from DN15 to DN3200 (1/2" to 128") with pressure ratings up to PN25 / Class 300.

Product Range

Product Category	Primary Components	Size Range	Movement Capability	Standard Flange Drilling
Single / Double Sphere Rubber Expansion Joint	EPDM / NBR / FKM Body, Carbon Steel / Ductile Iron Flanges	DN15 – DN3000 (1/2" – 120")	Axial Compression: up to 25mm Axial Extension: up to 15mm Lateral Deflection: up to 22mm	EN1092-2 PN10/16/25 ASME B16.5 Class 150/300 JIS 10K/16K
Double Flange Limit Expansion Joint	Ductile Iron GGG50 / Carbon Steel Body, NBR/EPDM Seal, Steel Tie Rods	DN50 – DN2000 (2" – 80")	Axial Displacement: ±50mm (Adjustable via limit studs)	EN1092-2 PN10/16/25 BS4504 / DIN 2501
Dismantling Joint	Retaining Ring, Sleeve, Gland, Tie Rods (Grade 8.8 / SS304)	DN50 – DN2400 (2" – 96")	Axial Adjustment: ±25mm to ±50mm for valve installation/removal	EN1092-2 PN10/16/25 ASME B16.5 Class 150
Stainless Steel Bellows Expansion Joint	SS304 / SS316L / SS321 Bellows, Weld End or Flanged Ends	DN15 – DN1200 (1/2" – 48")	Axial, Lateral, and Angular thermal expansion compensation	ASME B16.5 Class 150/300 EN1092-1

Elastomer & Metallic Material Selection

Rubber Compounds

Material	Suitable Media / Applications	Operating Temperature
EPDM (Ethylene Propylene Diene Monomer)	Water, hot water, mild acids, alkaline media	-20°C to +120°C
NBR (Nitrile Rubber)	Petroleum products, hydrocarbons, lubricating oil, compressed air	-20°C to +80°C
FKM (Fluoroelastomer / Viton)	Concentrated chemical acids, high-temperature oils, corrosive fluids	-20°C to +200°C
Neoprene (CR)	Seawater, sewage, weathering, ozone exposure	-15°C to +90°C

Flange & Retaining Ring Materials

Material Category	Available Materials / Grades
Ductile Iron	GGG40 / GGG50 (EN-GJS-400-15 / EN-GJS-500-7)
Carbon Steel	Q235B / ASTM A105
Stainless Steel	AISI 304 / 316 / 316L

Mechanical Performance Standards

Parameter	Specification	Application / Notes
Burst Pressure Margin	Minimum design safety factor of 3:1 relative to maximum working pressure	Example provided: PN16 joints are hydraulically burst-tested to ≥ 4.8 MPa
Vacuum Rating	Up to 750 mmHg vacuum	Standard rubber expansion joints, as specified
Internal Vacuum Rings	SS304 / SS316	Used in suction-side pump lines to help prevent arch collapse
Flange Parallelism	Error within 1.0 mm	Flange alignment requirement
Bolt Hole Circle (PCD) Tolerance	±0.5 mm	CNC-machined flange drilling to match mating flanges

Standards & Quality Control

Manufacturing operates under ISO 9001:2015 quality management procedures. Pressure testing and dimensional verification conform to ISO 5208 and EN 12266-1.
Raw Rubber Compound Testing (Rheometer & Tensile Test)
→ Molded Vulcanization (Hydraulic Pressing)
→ Flange CNC Machining & Surface Coating
→ Assembling Body, Flanges & Limit Control Rods
→ Hydrostatic Pressure & Vacuum Testing (100% Batch Sampling)
→ Dimensional Inspection & Marking
→ Final Packaging & Mill Test Report (EN 10204 3.1)

In-House Testing Capabilities
Rheometer & Rubber Compound Analysis: Verifies Mooney viscosity, vulcanization curve, tensile strength (≥ 15 MPa), and elongation at break (≥ 400%).

Hydrostatic Pressure Testing: Every batch undergoes shell pressure testing at 1.5 times the nominal working pressure (e.g., 2.4 MPa for PN16) held for a minimum of 10 minutes without pressure drop or deformation.

Cyclic Movement & Fatigue Test: Samples undergo 10,000 continuous compression-extension cycles to confirm rubber memory retention and structural integrity.

Coating Thickness Gauge: Epoxy powder coating thickness on ductile iron castings and steel bodies is measured to ensure a minimum of 250 µm (DFT) for underground burial protection.

Traceability: Heat numbers for metal castings and batch numbers for rubber compounds are permanently stamped on flanges and recorded in EN 10204 3.1 certificates.

Flanged Single Sphere Rubber Expansion Joint Pn16

Customization & Supply Options

Control Unit & Limit Rod Configurations

Optional limit rods, tie bars, or compression stops prevent excess pipeline elongation under unanchored pressure thrust.

Protective Linings & External Shields

PTFE/FEP internal sleeves for high-purity or ultra-corrosive media; external flame-resistant protective covers for high-temperature environments.

Surface Coating Options

Fusion Bonded Epoxy (FBE) coating (RAL 5005 / RAL 5015), Hot-Dip Galvanizing according to ASTM A153, and Polyurethane (PU) external coatings.

Custom Flange Drilling & Lay Lengths

Non-standard face-to-face dimensions, special PCD drilling patterns (e.g., AWWA C207, BS10 Table E, JIS 5K/10K/16K).

Packaging & Export Logistics

Heavy-duty ISPM 15 heat-treated wooden cases with internal steel strapping, flange face protective caps, and custom crate labeling.

Our Factory

FAQ

Q: What is the primary purpose of adding limit tie rods to rubber expansion joints?

A: Limit tie rods restrain the expansion joint from extending beyond its maximum design movement limits when unanchored pipeline forces or line pressure thrusts occur. They prevent joint pull-off and protect connected pumps, valves, and surrounding pipe anchors from mechanical stress.

Q: How do I choose between EPDM, NBR, and FKM elastomeric liners?

A: Select EPDM for general water supply, wastewater, hot water, and outdoor weathering. Use NBR when the medium contains mineral oils, petroleum products, hydraulic fluids, or compressed air with oil mist. Specify FKM (Viton) for high-temperature oil lines or aggressive chemical media up to 200°C.

Q: What are the main advantages of a double-flanged limit expansion joint compared to a standard flexible joint?

A: A double-flanged limit expansion joint uses a metallic telescopic sleeve with an elastomeric seal and high-tensile limit studs. It accommodates larger axial adjustments, offers structural stiffness against shearing forces, and acts as an anchor-locking mechanism during pipeline maintenance or pump replacement.

Q: Can your rubber expansion joints handle vacuum pressure on pump suction lines?

A: Standard single-sphere rubber joints handle light vacuum up to 750 mmHg. For full vacuum or negative pressure conditions on pump suction inlets, we supply joints fitted with internal SS304 or SS316 vacuum support rings to prevent the rubber arch from collapsing inward.

Q: What test documentation is provided with shipments?

A: Each order includes an EN 10204 3.1 Mill Test Certificate detailing rubber mechanical properties, chemical analysis of metal components, hydrostatic test pressure charts, and coating thickness records. Third-party inspection (SGS, TÜV, BV) and EN 10204 3.2 certification are available upon request.

Q: What is the typical service life of your rubber expansion joints under standard operating conditions?

A: When operated within specified pressure ratings, movement allowances, and media temperature limits, the expected service life of our vulcanized EPDM/NBR rubber expansion joints is 8 to 12 years in above-ground installations, and up to 15 years in indoor climate-controlled environments.

Request a Quote

Submit your project parameters to receive a technical proposal and quotation within 24 hours.
Email: anzhiyuan@yhmadeinprc.com.cn
Required Technical Details: Nominal pipe size (DN/NPS), working pressure (PN/Class), fluid medium, operating temperature, end connection standard, and limit rod requirements.

We're well-known as one of the most experienced joint manufacturers in China. With a professional production team, we are able to meet the needs of the majority of our customers. Welcome to buy discount joint in stock here from our factory. Contact us for pricelist and free sample.