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Elbow pressure balanced expansion joints

Elbow Pressure Balanced Expansion Joints or Corner Relief Expansion Joints are the types of Pressure Balanced Expansion Joints, which are used where pressure thrust forces on equipment or piping is unacceptable and the direction of the pipe system also changes. In order to understand the primary advantage of an Elbow Pressure Balanced Expansion Joints, it is important to understand how ordinary Expansion Joints influence the pipe system, in which it is installed.
When a pipe system with an ordinary Axial Expansion Joint installed is pressurised, the pressure reaction force as well as the force needed to move the pipe Expansion Joint is transmitted to the pipe system. The pressure thrust force can be considerable, generating high demands and stresses on the guides and fix points used for supporting/fixing the pipe system.

By installing Elbow Pressure Balanced Expansion Joints, the pressure thrust force is balanced internally within the Expansion Joint and only the spring rate force, which is needed to move the Pipe Expansion Joint is transmitted to the pipe system.
This reduces the load acting on the guides/fix points, which further reduces the need for supporting structures. This enables the use of lighter guides that can deliver significant savings, especially where structural and foundation work is impractical. This feature makes Elbow Pressure Balanced Expansion Joints the preferred choice for pipe systems, where pressure thrust loads acting on flanges and/or connected equipment such as turbines is avoided.

Design range and scope of supply within Elbow Pressure Balanced Expansion Joints

Elbow Pressure Balanced Expansion Joints are available in all sizes and materials.

Dimensions

DIMENSIONS:
DN 15-12.000

Pressure

PRESSURE:
Up to 150 barg or more if required

Temperature

TEMPERATURE:
-165°C to +1000°C

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MATERIALS:

Austenitic stainless steels, High alloys, Duplex, Titanium, Hastelloy,
Incoloy, Inconel, Alloy 59

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DESIGN CODES:

EN 13445, EN 13480, EN 14917
ASME VIII, div.I, ASME B31.3
ASME B31.1, EJMA, AD 2000
and others on request

Test and Quality Control

TESTS:

Radiographic examination (X-ray), Helium leak testing, Pressure test, Air test, Dye penetrant test, Magnetic particle examination and many more

ENGINEERED

ELBOW PRESSURE BALANCED
EXPANSION JOINTS

ELBOW PRESSURE BALANCED EXPANSION JOINTS

CASE STORIES

PRESSURE BALANCED CORNER EXPANSION JOINTS

Pressure Balanced Corner Expansion Joints with ring reinforcement for high pressure (145 barg, tested at 200 barg).

ONE-TO-ONE
REPLACEMENT

This Elbow Pressure Balanced Corner Expansion Joint is installed in the off-gas pipeline in a Northern European Chemical plant.

100% HASTELLOY
ELBOW PRESSURE BALANCED

This Elbow Pressure Balanced Expansion Joint is made completely from Hastelloy as it is installed in a demanding environment at the chemical reactor.

ELBOW PRESSURE BALANCED EXPANSION JOINTS

TECHNICAL DESCRIPTION

APPLICATION

Elbow Pressure Balanced Expansion Joints are used in pipelines with a change of direction. Elbow Pressure Balanced Expansion Joints are used with low pressure turbines, with condensers and also with pumps and other equipment, that may be susceptible to pressure loads.

TYPES & DESiGNS
Elbow Pressure Balanced Expansion Joints are avalable in many designs depending on the operating parameters.
HOW DOES IT WORK
Elbow Pressure Balanced Expansion Joints can be designed for absorption of axial and lateral movement. If only axial movement is required, the Expansion Joint is designed with only one flow bellow and one balancing bellow after the bend. If lateral movement occurs the unit generally is designed with two flow bellows, similar to a tied universal unit. The balancing bellows are connected to the flow bellows and pipe system through tie rods so the balancing bellow lengthens when the line bellows are compressed axially and thereby creates a constant volume. That is why Pressure Balanced Expansion Joints are also known as constant volume Expansion Joints. The pressure thrust force is absorbed as a pulling force in the tie rods, whereby the section between the tie rods including the bend acts as a balancing chamber. The balancing bellows and the flow bellows have inside the chamber exactly the same cross-sectional area and this creates a balance in the pressure thrust forces. Thereby the bend/pipe system corner is freed from any stresses. This type of Expansion Joint is used when there is a change in the direction of the pipe system and is considered the ideal solution on cross over piping on turbines.

HOW DOES THE
ELBOW PRESSURE BALANCED
EXPANSION JOINTS
WORK?

This animation is showcasing how movements are absorbed by the Elbow Pressure Balanced Expansion Joints

BELMAN YOUTUBE CHANNEL

More animations on how different Expansion Joint types absorb movements can be seen on the Belman Group Youtube channel

ADVANTAGES

What are the advantages of using Elbow Pressure Balanced Expansion Joints?

  • Reduce / eliminate costs for fix points
  • Balance the system
  • Reduce piping costs
  • Reduce external loads on connected equipment.

QUALITY & TESTS

Belman is known for high quality products and therefore our quality control is a fundamental part of our business. All processes during production designed by the Belman quality engineers, is strictly follow and implement according our procedures and instructions and carefully inspected by Belman quality inspectors. All checks and inspections are done according to the strict prevailing Belman quality control procedures which is part of the Belman ISO 9001 quality management system approved by DNV.

 

ITP & Test
Inspection test Plan generated by the quality management system makes sure that each step of manufacturing has the appropriate inspection points such as Hold and Witness points.

Based on manufacturing code, project specification, application, media, and eventual ship classification rules Belman performs a large variety of quality tests including destructive, non-destructive testing and proof testing. All tests can be witnessed by the 3rd part based on the customer and classification requirements.

  • Destructive test: such as life cycle test and burst test to validate the design, i.e., vessels and offshore platforms
  • Non-destructive test such as Visual testing, dye penetrant test, Radiography examination, Magnetic testing, ultrasonic testing, hardness testing and PMI for all applications
  • Proof tests: leak test with air, leak test with helium and former gas, hydrostatic pressure test for all application

ELBOW PRESSURE BALANCED EXPANSION JOINTS

INSTALLED

WE HAVE ENGINEERED

EXPANSION JOINTS SINCE 1994

This enable us to find you the optimum solution to your piping system.

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