Kraloy Expansion Fttings accommodate for conduit thermal expansion and contraction. Expansion joints are required when the temperature change is greater than 25°F (14°C). For conduit installed indoors, the range of expansion and contraction can be calculated using the maximum air temperature plus the heat contributed by the conductors inside the conduit and minimum air temperature expected. Expansion joints are not required indoors unless there are widely varying temperatures such as the attic of a building.
Conduit installed outdoors, exposed to direct sunlight, will be considerably hotter than the air temperature. As a guideline in this case, add 27°F (15°C) to the temperature change. Expansion joints should be installed to allow for all anticipated temperature changes.
The perfect expansion fitting for short runs of PVC, Kraloy One Piece Expansion Joints(OPEJ) control 1 1/4" of thermal expansion or contraction on a 30 foot conduit run (or less) regardless of the temeprature at the time of installation.
Karloy PVC fittings are resistent to a wide range of chemicals such as acids, alkalis or salt solutions. Available in an extensive range of sizes, expansion fittings are easily installed for each specific installation.