Industrial applications can be separated into general categories based on the media composition (air or gas) and temperature. The following section is designed to aid in the selection of the appropriate expansion joint for the specific application range. All plants are different, therefore, the service locations and temperatures may vary. This section is only a guide and should be confirmed with a UNAFLEX® engineer.
Ambient Air Services
Ambient temperature clean air without particulate or chemicals to damage the flexible element. Expansion Joint is used frequently for vibration and sound attenuation from fan equipment.
A UNAFLEX® integrally flanged elastomeric joint is suggested, using either the Therma-Flex or Mighty Span styles. Neoprene or EPDM single layer belts are frequently used.
Hot Air Services
Clean air, after coming into contact with hot flue gases at the air pre-heater where temperatures are elevated with minimal particulate and or gas carryover. Expansion joint will see thermal movements and vibration. Elevated temperatures require a composite flexible element and a flow liner.
A Therma-Flex flat composite belt with a bolt or weld in frame design and a flow liner is suggested. The weld-in outboard angle frame design with field welded flow liner (TWCP600VIFL) is shown.
Low to Moderate Temperature Flue Gas Services
Flue gas which has passed through an air pre-heater and dust collector to reduce the temperature and particulate level. Flue gas may cycle near the dew point where condensation can occur and chemicals are present. Expansion joint may see thermal movement vibration and chemical attack.
A UNAFLEX® single-layer belt with chemical barrier is suggested in either integrally flanged or flat belt type—such as the Therma-Flex weld in outboard angle frame design and PTFE-coated single-layer belt with gas film layer (TWFPR500TA) shown.
Hot Flue Gas Services
Flue gas directly after combustion stage at elevated temperatures with possible particulate present. Expansion joint is used for possible large thermal movements at elevated temperatures.
Therma-Flex high temperature composite flat belt style with setback frames, cavity pillow and flow liners are suggested. The standard "Z" frame design with telescoping flow liners (ZZWCP1000FPRP shown) or "J" frame with shop liner are two designs used in these applications.