Expansion fittings are used in aboveground installations where temperature changes are anticipated to exceed 25°F (14°C) . Expansion fittings are usually used where the straight run length is greater than 25 feet and expected temperature change is greater than 60°F.
What is the purpose of expansion coupling?
Expansion couplings are used mainly to connect two pieces of pipe together .
What is an expansion fitting?
Expansion Fittings accommodate for conduit thermal expansion and contraction to compensate for length changes due to temperature variations in exposed conduit runs. Expansion joints are required when the temperature change is greater than 25°F (14°C).
How does an expansion coupling work?
Metal expansion joints are mostly used in applications with the issue of thermal expansion. If the temperature of the pipe increases, the metal expansion joint compresses to compensate for the movement and alleviate stress from the pipe .
Can you bury a PVC expansion fitting?
Do you guys ever worry about PVC expansion fittings in underground installations? No, never. They aren’t listed for direct burial anyway .
Does PVC conduit need expansion joints?
All conduit pipe and fittings expand and contract with changes in temperature. ... run of PVC conduit, the conduit will undergo 3.6′′ of expansion or contraction. Use of Expansion Joints. In installations where the expected temperature variation exceeds 25°F expansion joints must be used.
Where are expansion fittings required?
Expansion fittings are needed in abo- veground installations where temperature chang- es are anticipated to exceed 25°F (14°C) . When the straight run length is greater than 25 feet and expected temperature change is greater than 60°F expansion fittings are usually needed.
Do you need expansion joints?
Expansion joints are virtually never needed with interior slabs , because the concrete doesn’t expand that much—it never gets that hot. Expansion joints in concrete pavement are also seldom needed, since the contraction joints open enough (from drying shrinkage) to account for temperature expansion.
What can I use for expansion joints?
Expansion joints must be sealed with a flexible sealant, like QUIKRETE® Self-Leveling Polyurethane Sealant or QUIKRETE® Non-Sag Polyurethane Sealant ...or an expansion joint strip, to prevent water from penetrating the joint and deteriorating the sub-base.
Why do buildings have expansion joints?
Expansion joints are separations between structures, simply gaps, to allow them to move and reduce stresses that may occur . Often, these gaps are filled with an Expansion Joint System to fill in the void to ensure walkability, a complete building enclosure, waterproofing, and general serviceability of the structure.
How do you calculate PVC expansion?
The total expansion change can be calculated as follows: Total expansion change in inches = (coefficient of thermal expansion) x (maximum temperature range) x (length of run in inches) . Example: Total expansion change = (3.38 x 10-5 in./in./°F) x (120 ̊F) x (90ft x 12in./ft) = 4.38 in.
What is a PVC expansion fitting?
Expansion Fittings accommodate for conduit thermal expansion and contraction to compensate for length changes due to temperature variations in exposed conduit runs. Expansion joints are required when the temperature change is greater than 25°F (14°C).
What is a PVC expansion coupling used for?
PVC expansion couplings are used at any point where the expanding or contracting of one side of the pipe is a concern . The couplings allow the PVC to move along with the expansion rather than putting stress on the joint. They come in any size in which the PVC is available.
How much does PVC pipe expand and contract?
ABS, PVC and CPVC pipe, like other piping materials, undergo length changes as a result of temperature variations above and below the installation temperature. They expand and contract 4.5 to 5 times more than steel or iron pipe .
How much does PVC conduit expand?
PVC conduit expands 4.1′′ for each 100 feet of run and a 100°F temperature change.
