RETURNING CLIENT ORDERS ANOTHER
10-METRE-LONG HINGED
FLEXIBLE JOINT

A returning client has ordered a 10-metre-long, Double-Hinged Flexible Joint with a nominal diameter of DN 1900, along with three DN 1400 Tied Expansion Joints. These new Flexible Joints will be installed in a different main feed circuit of the Northern European oil refinery, separate from the line where the client’s previously Belman-supplied 10-metre-long Expansion Joint is installed.

 

CLIENT ISSUE
Previously, the oil refinery had ordered a 10-metre-long, Double-Hinged Flexible Joint from Belman, and was very happy with the engineering expertise, production capabilities and overall cooperation. The delivered solution exceeded expectations in terms of design, quality and performance. Therefore, when the refinery required a similar 10-metre-long Expansion Joint for another main feed circuit in its plant, it once again turned to Belman. For the earlier project, three DN 1400 Tied Expansion Joints were also required, but that part of the order was not awarded to Belman. This time, however, the satisfied client returned to Belman requiring all the Expansion Joints and chose to place the entire order with Belman, based on the proven performance of the 10-metre-long Flexible Joint solution.

 

BELMAN SOLUTION – a Double-Hinged Flexible Joint plus three Tied Expansion Joints
Based on the client’s specifications and drawings and leveraging the engineering know-how from the previously delivered 10-metre-long Double-Hinged Flexible Joint, Belman engineered another 10-metre-long Hinged Expansion Joint as well as engineered the three DN 1400 Tied Expansion Joints. Both solutions met the client’s expectations in full and the order was awarded to Belman.

The key highlights of these remarkable designs are:

The reordered 10-metre-long Flexible Joint can accommodate +/-400 lateral movement (range 800 mm) absorption
The flanged Double Bellow Expansion Joint with hinges is designed to accommodate +/-40 mm axial movement (range 80 mm) and +/400 mm lateral (range 800 mm) movement in combination. This represents a very large movement range for a DN 1900 Expansion Joint. To safely absorb these movements without overstretching or over-compressing the Bellows convolutions, a long built-in length of 10 metres was required, particularly to handle the lateral movements. Thus, the length of the Flexible Joint is determined by both the diameter and the required movement absorption. The lateral movements arise from ground settling, while the axial movements result from the temperature fluctuations. You can read more about the engineering of this solution here:

Special design features of the 10-metre-long Hinged Flexible Joint are:

• The hinges provide stability to the Expansion Joint construction and control the movement absorption. On this Double-Hinged Expansion Joint, the hinges mainly support the weight of the middle pipe between the bellows, including the media. The hinges have slotted holes to allow axial movement absorption.
• The Expansion Joint is laterally pre-set and equipped with a position indicator on the hinges for axial movement.
• The Double-Hinged Expansion Joint is designed for -0,5/+10 barg, ensuring sufficient robustness for the operating pressure and resistance to potential water hammer.
• The materials were carefully selected to withstand both the media (brackish water) and the operating environment.
• Inner sleeves were installed to protect the Bellows against the high flow velocity and corrosive media.
• A coating system was applied to the flanges and the middle pipe to protect the Double-Hinged Expansion Joint. This includes a zinc-rich epoxy primer, a polyamide-cured epoxy inner coat and a final aliphatic polyurethane topcoat.

Three 1.44 metre-long Tied Double Flexible Joints, size DN 1400, for the absorption of axial movement and lateral movement in combination.
These three DN 1400 Tied Flexible Joints are each fitted with four sets of tie rods. These Double Bellow Expansion Joints feature specially designed square flanges to achieve cost efficiency. They are capable of absorbing +/-25 axial movement (range 50 mm) and +/- 15 mm lateral movement (range 30 mm) in combination, with tie rods ensuring precise control of the movement absorption.

Special design features of the DN 1400 Expansion Joints are:

• Tie rods are integrated to control the absorption of movement and prevent column instability (squirm).
• The tie rods are not designed to carry pressure thrust. After installation, the inside nuts (both ends) must be moved up against the flange with 15 mm clearance and the outside nuts (both ends) loosened by 2 mm, as per Belman’s instructional drawings for the client.
• Inner sleeves are installed to protect the Bellows from the high media flow velocity and corrosive media.
• The materials were carefully selected to provide resistance against the media (brackish water) and the operating environment.
• For corrosion protection, the carbon steel parts of the Expansion Joint (the flanges) are coated with a zinc-rich epoxy primer, an HS polyamide-cured epoxy intercoat and an HB aliphatic polyethene topcoat.
• The Flexible Joint is designed for -0.5/+10 barg, ensuring sufficient robustness for the operating pressure and resilience against potential water hammer.

 

Belman – proven experience in large-sized Expansion Joints
With decades of experience, Belman has established a strong track record in designing, manufacturing and handling large-sized Expansion Joints. Since 1994, we have delivered large-size solutions such as DN 2500 Finger Type Expansion Joints (with a DN 3800 balancing Bellow), a DN 4200 Universal Expansion Joint and an 8.1-metre-long FCCU Expansion Joint, among many others.