EHT Flashcards
2 Main Function of EHT
Freeze protection and Maintain Process
5 Types of heat tracing systems
- Stream Heat Tracing
- Hot Liquid Tracers
- Electric Resistance Heat tracing
- Inductoin Heat Tracing
- Zone Heaters
Ideal for high heat load and transfer quickly but limited between 100 to 200 feet.
Steam Heat Tracing
Most expensive, Temp can be maintained above and below those of steam heaters
Hot liquid Tracers
Uses piping itself as the heating element, Heats by Eddy Currents and hysteresis
Induction Heat tracing
More Economical,
Used in long piping system
most common type is self regulating tracers
Electric resistance Heat tracing
high rate of burn out
popular for industrial use
two bus wires with smaller heating wire
zone heaters
long life most reliable electric heating cable
energy efficient
limited temperature range
Self regulating cables
can be field cut if heating element fails circuit is maintained
relatively fragile
can self destruct from its own heat
zone
temperature at which certain magnetic materials undergo sharp chnage in their magnetic properties.
Curie point
High temperature capable
high heat transfer
very expensive difficut custom design not commercially exploited
Inductance
