Best Practices for Expansion Joints in the Process Industries

The right equipment and proper maintenance can extend the life of expansion joints, and add to a system’s total lifespan.

Operating equipment in the process industries can be fraught with dangers. Specifically, rubber expansion joints used at high temperatures or improperly installed, and operating pumps away from the best efficiency point (BEP), can cause wear, failure and extended downtime in operation. One common issue with rotating equipment is vibration, and one way to avoid vibration is to use expansion joints and use them properly.

In addition, piping systems require flexibility, according to the Fluid Sealing Association (FSA). Inadequate flexibility and vibration from fluid borne noise can lead to wide-scale damage, and expose personnel to the risk of injury.

Rubber expansion joints are flexible connectors fabricated of natural or synthetic oil-based elastomers with fabric reinforcement. Some typical materials used in their construction include:

Ethylene propylene diene monomer (EPDM)
Neoprene
Chlorobutyl
Hypalon

These materials usually combine with polyester or nylon and wire reinforcing. These connectors are particularly suited to combat the fluid noise that is common with rotating machinery.

Rubber expansion joints are known for their durability and can withstand extreme environments. Therefore, they are most common in harsh applications and those that carry heavy solids such as:

Chemical Processing
Oil & Gas
Power Generation
Water/Wastewater
Mining
Steel Mills
HVAC/Building Services

When choosing a rubber expansion joint, there are a number of factors to consider. Purchasers should understand these elements of a system in order to select the best joint for the particular application.

Size by overall length is required.
What is the operating temperature?
What is the viscosity of the pumped fluid?
Are there solids in the fluid?
What is the pressure?
What is the estimated movement in the system?
What is the footprint of the space?
Is the elastomer used in the joint chemically compatible with the process fluid?
What is the total cost of ownership?

Maintenance

The best advice for maintaining equipment is to follow the manufacturer’s recommend maintenance schedule. the manufacturer’s manual for a product will supply information on installation, operation and maintenance. The manual will contain all of the information needed to care for that piece of equipment. In the pumps industry, it is all too common for end users to ignore the manual.

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