This document discusses flexible connections in piping systems. Flexible joints, such as bellow expansion joints, are used to absorb thermal expansion or movement between pipes. There are several types of flexible joints, including hinge joints, gimbal joints, slip joints, axial joints, untied universal joints, and universal joints. Flexible hoses can also be used to connect distant points with movement. When designing flexible joints, it is important to consider the expected movement, thrust forces, anchoring and guiding, and how they will be incorporated into the overall piping system design. Flexible connections require special engineering due to their extra costs and need for periodic inspection and maintenance.

1. CHAPTER 7
FLEXIBLE CONNECTIONS
ABI ZIHNI
PIPING DEPARTMENT – PT REKAYASA
INDUSTRI

2. OUTLINE
1. INTRODUCTION
2. BASIS DESIGN OF BELLOW ELEMENTS
3. APPLICATIONS OF BELLOW EXPANSION JOINTS
4. COLD SPRUNG OF EXPANSION JOINT
5. TYPES OF EXPANSION JOINTS
6. TYPES OF FLEXIBLE HOSES

3. INTRODUCTION
“Flexible joint are used in piping systems to
absorb thermal expansion or terminal
movement”

4. General Nomenclature Of Flexible
Joint

5. Why we should use flexible
joint??
• Available space is not enough to provide
expansion loop
• Large high-temperature & low pressure which
is required huge expansion loop that would
have been too expensive and too much
space to install
• Equipment allowable load is so low
• A line that cannot tolerate the pressure drop
from the loop
• To isolate vibration from process machine to
the piping

6. Why we shouldn’t use flexible
joint??
• Special items which is required special
engineering
• Extra cost
• Need periodic inspection and maintenance
• It requires expertise in engineering
• It is difficult to provide insulation covering to
accommodate the flexing requirement
• A horizontal joint tends to trap liquid and
sediment
• Special supports are needed
• The flexible joint poses weaker link in the
system

7. BASIS DESIGN OF FLEXIBLE
ELEMENT

8. BASIS DESIGN OF BELLOW
ELEMENT
ecom ≤ ex, allow

9. BASIS DESIGN OF BELLOW
ELEMENT

10. BASIS DESIGN OF BELLOW
ELEMENT
Torsional movement
“The bellow shouldn’t be
subjected to any torsional
moment”

11. BASIS DESIGN OF BELLOW
ELEMENT
ex ≤ ex, allow
Non-concurrent movement :

12. BASIS DESIGN OF BELLOW
ELEMENT
Concurrent movement :

13. COLD SPRUNG of Expansion Joint
“Expansion joint is generally cold spring for 50% or
more of the expected movement”
Main advantages
• Force reduction
• Stability against internal pressure
• Belllow clearance
• Component clearance such as internal sleeves,
external covers, tie devices.

14. Thrust Force

15. Anchoring & Guiding

16. Anchoring & Guiding
Effect of Thrust Force without Anchor
Effect of thermal expansion without proper guides

17. Anchoring & Guiding

18. Special Guide
Alignment Guide

19. Anchoring & Guiding

20. Type of Expansion Joint
1. Hinge
2. Gimbal
3. Slip Joint
4. Axial Joint
5. Untied Universal Joint
6. Universal Joint

21. Hinge

22. Gimbal

23. Slip Joint

24. Axial Joint

25. Untied Universal Joint

26. Universal Joint

27. Flexible Hose
“Flexible Hoses are used to connect
two distant points with considerable
relative movement”

28. Types of Metallic Hoses

29. Types of Metallic Hoses

30. Hose Length Required for General Loop

32. Comparison between Expansion Joint,
Expansion Loop, and Flexible Hoses

33. Design Consideration of Exp.
Joint in Piping System

34. Design Consideration of Exp.
Joint in Piping System

35. TERIMA KASIH