KRJ Shouldered Flexible Coupling
Key Features
-
Flexible Pipe Connection
The KRJ coupling creates a flexible connection between shouldered steel pipes, fittings, and valves. The joint can accommodate a certain amount of thermal expansion, contraction, and pipe deflection, helping reduce stress caused by pipeline movement.
-
High-Pressure Performance
The coupling is designed for demanding piping applications with a maximum working pressure of up to 610 psi (4200 kPa / 42 bar), depending on size, pipe configuration, gasket selection, and application conditions.
-
Reliable Sealing
The sealing system uses a resilient gasket compressed between the pipe ends and coupling housing. This provides a reliable seal while allowing the joint to accommodate controlled pipeline movement
-
Durable Ductile Iron Housing
The coupling housing is manufactured from ductile iron conforming to ASTM A536, Grade 65-45-12, providing the strength and durability required for industrial piping applications.
The standard housing finish is epoxy powder coating, while alternative coating options are available for specific environments.
-
Wide Application Range
The shouldered flexible coupling can be used with shouldered steel pipe systems for conveying water, air, slurry, and other compatible industrial media.
Its flexible connection design makes it particularly suitable for piping systems exposed to vibration, thermal movement, or installation-related deflection.
Applications
-
Mining and mineral processing
-
Mine water supply and drainage systems
-
Slurry and paste transportation
-
Chemical processing pipelines
-
Industrial water systems
-
Municipal water and drainage
-
Compressed air systems
-
Petroleum and industrial fluid handling
-
Fire protection piping systems
-
Industrial pipeline maintenance and expansion projects
Construction and Materials
-
Coupling Housing
The housing is manufactured from ductile iron to ASTM A536, Grade 65-45-12.
Standard coating: Epoxy powder coating
Optional: Other coating systems are available according to application and environmental requirements.
-
Gasket Options
The KRJ coupling can be supplied with different gasket materials according to the service medium and operating temperature.
-
Grade T – Nitrile
● Temperature range: -20°F to +180°F (-29°C to +82°C)
● Suitable for selected oil-related services
● Suitable for specified water-related applications up to +150°F (+66°C)
● Suitable for oil-free dry air applications up to +140°F (+60°C)
● Not recommended for hot water or steam service
-
Grade E2 – EPDM
● Temperature range: 0°F to +180°F (-18°C to +82°C)
● Suitable for wet and dry oil-free air applications within the specified temperature range
● Not compatible with petroleum-based services or steam
Gasket selection should be based on the operating medium, temperature, pressure, and service conditions.
-
Bolts and Nuts
Standard fastening components are zinc-electroplated carbon steel.
● Track bolts conforming to applicable ISO 898-1 mechanical property requirements
● Hex nuts conforming to applicable ISO 898-2 requirements
● Zinc electroplating according to ASTM B633
● Hot-dip galvanized fastening components available as an option
Specifications
| Specification | Details |
| Product | KRJ Shouldered Flexible Coupling |
| Connection Type | Shouldered pipe connection |
| Compatible Pipe | Shouldered steel pipe |
| Size Range | 2-14 in. / DN50-DN350 |
| Maximum Working Pressure | Up to 610 psi / 4200 kPa / 42 bar |
| Housing Material | Ductile Iron, ASTM A536 Grade 65-45-12 |
| Standard Coating | Epoxy powder coating |
| Gasket Options | Grade T Nitrile / Grade E2 EPDM |
| Application | Industrial piping, mining, slurry, water, air and other compatible services |
How the Flexible Coupling Works ？
The KRJ shouldered flexible coupling uses a housing-and-gasket sealing system to secure the pipe connection.
During installation, the gasket is positioned between the pipe ends and the coupling housing. As the bolts are tightened, the housing compresses the gasket against the pipe surface to create a sealed connection.
The flexible joint design allows controlled movement of the connected pipes, including axial movement and angular deflection, within the applicable design limits.
This flexibility can help accommodate thermal expansion, contraction, vibration, and minor pipeline movement without transferring excessive stress to the connected piping system.
Installation and Maintenance
For reliable performance, the pipe ends should be properly prepared and aligned before installation.
The basic installation process includes:
-
01
Inspect and clean the pipe ends.
-
02
Position the gasket correctly on the pipe ends.
-
03
Install the coupling housing around the joint.
-
04
Ensure the coupling is properly aligned.
-
05
Tighten the bolts evenly according to the specified installation requirements.
-
06
Inspect the completed joint before putting the pipeline into service.
During operation, periodic inspection should be carried out to check the coupling housing, gasket condition, bolt tightness, and overall joint integrity.
Actual installation procedures and torque requirements should follow the applicable product specifications and project standards.
Custom Pipe Coupling Solutions from GOLDDRILL
GOLDDRILL is a manufacturer and factory supplier of flexible pipe couplings and industrial pipe connection products.
We provide custom and OEM coupling solutions for mining, industrial piping, water systems, slurry transportation, and other demanding applications.
Our manufacturing capabilities support customization based on:
● Pipe size and dimensions
● Pressure requirements
● Gasket material
● Housing material
● Surface coating
● Connection configuration
● Operating medium
● Environmental conditions
Whether you require a standard shouldered flexible coupling or a custom pipe coupling for a specific industrial application, GOLDDRILL can provide factory-direct manufacturing and application-specific support.
Contact GOLDDRILL for shouldered flexible coupling, mining pipe coupling, and custom pipe connection solutions.
