How is the swivel joint of the loading arm connected to the pipeline?
The swivel joint of a loading arm is a key component in the loading arm system, essential for its normal operation. The swivel joint is made up of rotating parts and sealing components, primarily used to connect different components of the fluid loading arm, allowing relative rotation while bearing loads. It is one of the most important parts of the loading arm, with excellent sealing performance, high pressure resistance, and corrosion resistance, ensuring no leakage during the transfer of liquid materials.
There are two main types of rotating seals used in swivel joints: composite material seals and mechanical seals. Composite material seals generally offer better sealing performance and are used in applications where hydraulic cylinders have intermediate positioning. Swivel joints using composite material seals can be made more compact due to the smaller size of the seal itself, and these seals are also much cheaper than mechanical seals.
The composite material rotating seal consists of two parts: an outer ring and an O-ring. The O-ring supports the outer ring, making the entire rotating seal easier to install.
Mechanical seals, in theory, allow for non-contact sliding and can achieve a long lifespan. However, mechanical seals are more complex to manufacture, require higher precision, and are relatively more expensive.
The process of connecting the swivel joint to the track of the loading arm involves several key steps and considerations. Below is a detailed connection process:
Pre-Installation Preparation:
- Ensure that the swivel joint is intact and undamaged. Check for any minor damage or defects that could affect its performance.
- Ensure that the dimensions of the loading arm and the swivel joint are compatible. If there are any mismatches, adjustments or repairs should be made.
Installation Location and Alignment:
- When selecting a swivel joint, consider factors such as high temperature resistance, sealing performance, and simple structure to ensure the smooth operation of the loading arm's cooling system, as well as excellent heat transfer and dissipation.
- During installation, ensure that the input shaft of the gearbox is concentric with the motor shaft to ensure smooth mechanical operation, reduce wear, and improve efficiency.
- The outer part of the swivel joint should remain parallel to the flange to maintain system stability and reliability.
Connection Steps:
- For the connection between the loading arm and the jetty, standard flanges that match the loading arm should be used. The flange distance from the track surface should be between 3.7 to 4.0 meters.
- Start by installing the base swivel joint, followed by the vertical aluminum pipe, and finally the balance device. When installing the balance device, first raise the oil arm to an angle of about 60°, then install the pins on both sides of the balance device onto the hooks. Next, align the double ears of the pull rod at one end of the balance device with the single ear on the swivel joint housing, install the pin, and finally secure the cotter pin.
Adjustment and Testing:
- When adjusting the balance, place the oil arm in a horizontal position, unscrew the end cover of the balance device, and adjust the screws to ensure the loading arm remains stable within the range of -5° to 60°.
- After installation, conduct system tests and inspections to ensure that the connection between the swivel joint and the track is stable and reliable, with no leakage.
Precautions:
- During handling and storage, prevent the swivel joint from colliding or falling to protect the interface and internal components.
- For threaded connections of the swivel joint, ensure that the thread directions of the inner and outer pipes align with the rotation direction of the drum, and that the thread directions of the inner and outer pipes match.
- Use hoses to connect the swivel joint to the pipeline, avoiding rigid connections. This helps reduce the weight of the joint and extends its service life.
By following these steps and precautions, you can ensure that the connection between the swivel joint and the track of the loading arm is stable and reliable, and that the loading arm system operates normally.
