Flare Steam bellows expansion joint

1. Product Overview

The flare steam bellows expansion joint is a specialized metal corrugated compensator engineered for flare steam tracing pipelines in petrochemical, refinery and gas processing facilities. It is used to absorb axial, lateral and angular thermal displacements generated during heating and cooling cycles of steam piping, release thermal stress, mitigate vibration and protect adjacent pipes and equipment from deformation or cracking.

This expansion joint is designed for high-temperature steam service. A key feature is the perforated inner sleeve, which differentiates it from standard non-perforated type for water or low-temperature gas lines. Limit tie rods are normally equipped to restrain pressure thrust and prevent over-extension of the bellows under internal pressure. It can be supplied with butt-weld ends or flanged ends to match site piping requirements, manufactured in accordance with EJMA, ASME B31.3 and relevant domestic standards.

2. Structure & Function of Perforated Inner Sleeve

The perforated inner sleeve acts as a flow liner to shield the bellows from direct high-velocity steam erosion. Even more importantly, the evenly distributed small holes on the sleeve serve two core purposes: pressure equalization and condensate drainage.

Without these holes, steam trapped in the annulus between inner sleeve and bellows will build up differential pressure, which may cause bellows bulging, instability and premature fatigue failure. The holes balance pressure inside and outside the sleeve. Meanwhile, condensate formed by steam cooling can drain through these holes, avoiding liquid accumulation in the annular space. Standing condensate would lead to localized corrosion, or freezing damage in low ambient temperature conditions.

The holes are only machined on the inner sleeve, never on the bellows itself. The inner sleeve maintains a flow direction mark to ensure correct on-site installation. Material of inner sleeve matches bellows, normally SS321 or SS316L for high temperature and corrosion resistance.

3. Material & Technical Features

Bellows material options: SS321, SS316L, 310S, selected based on operating temperature and medium corrosivity.

• Limit tie rods: Control maximum movement, bear pressure thrust, prevent bellows overstretch.
• End connection: Butt weld or flange connection as per customer drawing.
• Application: Flare steam tracing lines, high temperature steam service with possible condensate.
• Design capability: Accommodate combined axial, lateral and angular thermal movements.

This expansion joint is custom-made according to working pressure, temperature, pipe size and displacement requirements. All parameters will be confirmed before production to meet site flare system operating conditions.

a) How can I get more details about your products?
You can send an email to our email address. We will provide catalogue and pictures of our products for your reference.We can also supply pipe fittings, bolt and nut, gaskets etc. We aim to be your piping system solution provider. 
b) How can I get some samples?   
If you need, we will offer you samples for free, but new customers are expected to pay express charge. 
c) Do you provide customized parts? 
Yes, you can give us drawings and we will manufacture accordingly. 
d) To which country have you supplied your products?
We have supplied to Thailand, China Taiwan, Vietnam, India, South Africa, Sudan, Peru , Brazil, Trinidad and Tobago, Kuwait, Qatar, Sri Lanka, Pakistan, Romania, France, Spain, Germany, Belgium, Ukraine etc. (Figures here only include our customers in latest 5 years.). 
e) I can't see the goods or touch the goods, how can I deal with the risk involved?  
Our quality management system conforms to the requirement of ISO 9001:2015 verified by DNV. We are absolutely worth your trust. We can accept trial order to enhance mutual trust.