The two-ply testable bellows are designed to provide the users comfort of predictability. In a two-ply testable bellows, each ply is designed to retain the full internal pressure load and temperature, providing a safety zone in the event a leak is formed in the inner ply.

Furthermore, by attaching a manometer to the outer ply, you can evaluate the status of the inner ply. If the pressure gauge shows that an inner ply leak has occurred, users would be able to purchase a new part and schedule for maintenance immediately without shutting the system down.

TYPICAL FEATURES OF A TWO-PLY TESTABLE EXPANSION JOINT
Each ply is designed to withstand the full line pressure and temperature. In the event of an inner ply leak, the outer ply is still capable of sustaining the system operating conditions.

Each two-ply testable bellows element contains stainless steel tube test ports with a coupling for accessory attachment. When combined with a pressure gage, one can quickly monitor whether the inner ply is retaining the pressure or if a leak has occurred. It is also common for the test port to be attached to an electronic monitoring system, wired directly into the plant control room. Each test port is held in place with a steel brace which ensures torque loading is not induced into the bellows neck during installation of accessories.

BELLOWS DESIGN
Bellows of pressure balanced expansion joints are designed according to EJMA 10 code. For high pressure applications multi layered bellows with reinforcing rings. According to the requested features like type of transported media, spring rate values (axial, lateral, angular) or operation temperature, pressure & life cycle bellows material could be customized.

CONSTRUCTION
Expansion Joints are the parts of pip¬ing system of pressurized equip¬ment. In this respect construction of the expansion joints are designed and produced according to European pressurized equipment directive (PED 2014/68/EU) as well as American Nation¬al Standard for piping process ASME Section VIII Div 1&2, ASME B 31.3.

All components of the expansion joints like, pipes, caps, flanges, tie rods etc… are checked by piping stress ana¬lysis thus enable us to se¬lect material type & thickness accord¬ing to permissible stress values.

GENERAL CAPABILITY RANGE FOR AYVAZ EXPANSION JOINTS
• Dimension: DN 15-6000
• Design pressure: Up to 150 bar (de¬pending on the diameter and tem¬perature)
• Lifting capacity: Up to 16 ton

TEST&CERTIFICATION
• Expansion Joints are the parts of piping system of pressurized equipment in this respect construction of the expansion joints are designed and produced according to PED 2014/68/EU&ASME U Stamp-U2 Stamp.
• Expansion joints are exposed to hydrostatic pressure at 1,5 times of design pressure.
• For full vacuum applications, vacuum test at 760 Hg/mm is also applicable.
• Additionally, gas leakage detection with helium is advised for proper tightness.