Convoluted Technologies has released a field inspection guide, and it is intended to assist in determining if an expansion joint should be replaced or repaired after extended service.
Replacement Criteria: If an expansion joint is in a critical service condition and is five or more years old, consideration should be given to obtaining a spare or replacing the unit at a scheduled outage. If the service is not of a critical nature, observe the expansion joint on a regular basis and plan to replace after approximately a decade service.
Cracking or crazing may not be serious if only the outer cover is affected, and the inner fabric is not exposed. If necessary, repair on site with rubber cement if the cracks are minor. Cracking where the fabric is exposed and torn, indicates the expansion joint should be replaced. If major blisters, deformations and/or ply separations exist in the tube, the expansion joint should be replaced as soon as possible. If the joint feels soft, gummy or too stiff to move, plan to replace the expansion joint as soon as possible.
Metal Reinforcement; If the metal reinforcement of an expansion joint is visible through the cover, the expansion joint should be replaced as soon as possible. Additionally, if any external metal reinforcement is exhibiting signs of fatigue or wear, the expansion joint should be replaced as soon as possible.
If leakage or weeping is occurring from any surface of the expansion joint, except where flanges meet, replace the joint immediately. If leakage occurs between the mating flange and expansion joint flange, tighten all bolts. If this is not successful, turn off the system pressure, loosen all flange bolts and then re-tighten bolts in stages by alternating around the flange. Remove the expansion joint and inspect both rubber flanges and pipe mating flange faces for damage and surface condition. Repair or replace as required.
Courtesy of Convoluted Technologies Pty Ltd.