Installation & Maintenance Tips for Rubber Bellow Expansion Joints

Absorb movement: Whether due to thermal expansion, vibration or pressure changes a properly installed expansion joint can accommodate movement without damaging the surrounding system.

Prevent premature wear: Incorrect installation can lead to excessive wear / leaks / or system failure.

Maximize longevity: Correctly installed joints last longer without needing frequent replacements or repairs.

Over-tightening or Under-tightening: Over-tightening damages the rubber, under tightening causes leaks and system inefficiency. The goal is to tighten up enough to hold the joint together but not so much as to stress the rubber.

Installing Against Flow Direction: Expansion joints are always installed in the direction of flow. When not installed properly they can distort the bellow and cause premature wear and failure.

Misalignment of Flanges: Unbalanced flanges place excessive load on the expansion joint and may cause performance degradation or leakage. Aligning flanges is important so the joint can absorb movement properly.

Check the System and Expansion Joint: Examine the installation system of the joint. Verify that no damage to the pipes, flanges or other parts will affect installation. In the same manner, check the rubber bellow expansion joint itself for defects or damage during transit or storage.

Gather Tools & Equipment: Prepare tools including wrenches, torque wrench, gasket materials and any flange adapters or spacers.

Prepare the Work Area: Get rid of anything around the installation site. Access all parts of the system and make sure the space is safe to work in.

Align the Expansion Joint: Align rubber bellow expansion joint with the flange and the pipe. This will position the bellow correctly relative to flow. For pressure relief systems, flow must be directed toward the body of the expansion joint.

Secure the Bolts: Start tying down the bolts by hand to hold the bellow in place. Then tighten the bolts in a crisscross pattern to even pressure distribution across the joint with a torque wrench. Follow manufacturer specs for torque values.

Double-Check for Misalignment: Check alignment of flanges and expansion joint after tightening to avoid pulling it out of shape. Missing an alignment here can cause damage later on.

Check for Leaks: When installed check the expansion joint for visible leaks. If you find leaks, loosen a little, adjust the joint, and retighten. A leak at this stage may be prevented by proper alignment and tightening.

Temperature and Environmental Factors: Extreme temperatures or harsh environmental conditions can degrade rubber expansion joints. Select the right working environment for the rubber type.

Proper Support: When installing additional support for the expansion joint, install it as per design specifications so that the joint is not moved or stressed excessively.

Visual Inspections: Check the joint for signs of wear, cracking or bulging. All apparent damage may be an indication that the joint isn’t working properly and needs attention.

Check for Leaks: Old seals can leak. Watch for leaks around the joint and correct any problems immediately.

Cleaning and Lubrication: Regularly clean the rubber bellows of dirt, debris or chemicals that may cause degradation. Apply a compatible lubricant to joint to prevent friction and wear.

Monitor Pressure Levels: Check system pressure regularly to make sure it is within the recommended range by the manufacturer. The expansion joint may be stressed beyond its useful life by high pressure and fail prematurely.

Cracking/Bulging of the Rubber: A cracked, torn, or bulging rubber bellow may indicate excess pressure, temperature or movement. This requires immediate attention to prevent system failure.

Leaks: Leaks around the expansion joint may indicate a degraded seal or the joint was not installed properly.

Unusual Noise or Vibration: A failing expansion joint may increase the vibration or unusual noise of the system. This can result from a misalignment or an inadequate expansion joint.

Replace or Repair the Rubber Bellow: Often replacement is the only option if the rubber bellow is badly damaged. You can sometimes repair minor cracks with specialized rubber repair kits, but this is usually only temporary.

Recheck Installation: If there are leaks or performance problems, check that the expansion joint is properly aligned and that the bolts are tightened.

Adjust System Pressure: If system pressure is too high, adjust pressure or install another type of expansion joint rated for higher pressures.

The Right Type of Expansion Joint: Select an expansion joint that fits the system pressure, temperature and movement requirements. Seek advice from the manufacturer on the proper material for your application.

Monitor Environmental Factors: Consider environmental factors like temperature fluctuations, chemical exposure or extreme weather when selecting a rubber bellow expansion joint.

See Early Warning Signs: Checking and maintaining your system regularly can catch problems early. Find excessive wear, unusual vibrations or leaks to avoid costly failures.