Examples of Common Types of Expansion Joints
Single Tied Expansion Joints for a Pipeline in Alaska
The expansion joint assemblies are fabricated entirely from stainless steel with a design pressure of 50 PSIG. They are designed with tie rods that do not permit axial movement, but allow for lateral movement up to 1/2″. The expansion joints will be used on a process line that contains exhaust gas and hydrocarbon vapor at a low concentration. It will connect an oil tank with a vapor control system.
The expansion joint assemblies are fabricated for a 12″ pipe and are designed for 2-1/2″ lateral movement. The design pressure is 276 PSIG with a design temperature of 626°F. 316L stainless steel was used for the bellows and tie rods. The expansion joints include 300 lb. raised face stainless steel flanges to accommodate low spring rate requirements.
Hinged Expansion Joints with Refractory Lining
Hinges cause the unit to bend in a single plane. The hinge mechanism is designed to accept the full pressure thrust.
- Design Pressure: 75.4 PSIG
- Design Temperature: 1400°F
- 100% X-ray Tested
- Pneumatically Tested weld seams to 83 PSIG
Elbow Pressure Balanced Expansion Joints
The expansion joints are fabricated for a 36″ pipe and are designed with Inconel® 625 grade LCF bellows. They include a liner provided with drain holes to prevent accumulation of corrosive condensation.
Inline Pressure Balanced Expansion Joints
- Design: 125 PSIG, Temperature: 244°F
- 304 SS Bellows, Flanges & Liners
- Designed to Balance 48,000 lb. of Pressure Thrust
Externally Pressurized Expansion Joints
These expansion joints are fabricated for a piping system in a steam plant. They include 304 SS bellows and carbon steel shell and flanges, and are designed for 150 PSIG and 350°F.
These expansion joints are designed for a 55″ diameter overhead vapor line at a refinery. The overall length is 310″ and the bellows are fabricated from 625 LCF. The expansion joint is designed for 50 PSIG and 1075°F.