Double Bellows Metal Expansion Joint for High Temperature & Pressure Pipeline
Product Overview
The double bellows metal expansion joint is assembled with two bellows segments and an intermediate connecting pipe. Free type and axial type are two mainstream configurations of this compensator. It is engineered to absorb axial thermal displacement generated by temperature variation in piping systems, release thermal stress accumulated on pipes and connected equipment, avoid structural deformation or damage caused by thermal expansion and contraction. This series of expansion joints is widely deployed in power generation, chemical processing, district heating, metallurgy and other industrial piping projects.
Key Features
- Free type double bellows expansion joint: Without tie rod assembly, simple construction and excellent flexibility. It is mainly designed to accommodate axial movement. Light weight and easy installation, ideal for low-pressure pipeline systems.
- Axial type double bellows expansion joint: Adopts constrained structure equipped with tie rods. The tie rods can bear pressure thrust produced by internal medium pressure, preventing over-extension of bellows. It can work steadily under medium and high pressure service conditions.
- Bellows material options include SS304 and SS316L stainless steel. End connections can be carbon steel flanged ends or welded ends according to customer requirements.
- Manufactured in accordance with EJMA standard. The product maintains reliable performance under high temperature and continuous cyclic operation.
- Compact overall dimension, convenient maintenance and long service life.
Technical Comparison
| Item | Free Type Double Bellows Expansion Joint | Axial Type Double Bellows Expansion Joint |
|---|---|---|
| Core Function | Absorb axial thermal displacement | Absorb axial thermal displacement, withstand pressure thrust |
| Structure | No tie rods, unconstrained design | With tie rods, constrained structure |
| Suitable Working Condition | Low pressure, heating pipelines | Medium & high pressure, chemical and power piping |
| Limitation | Cannot resist internal pressure thrust | Tie rods limit lateral deflection, mainly for axial movement |
Application Scenarios
This double bellows expansion joint is used for thermal compensation of industrial pipelines. Typical applications cover power plant steam & water piping, chemical process medium pipelines, municipal central heating networks, metallurgical fluid delivery systems and oil industry auxiliary pipelines. It effectively compensates thermal elongation of pipes and protects valves, pumps and other connected equipment from thermal stress damage.
