Carlon Expansion Joints for PVC Rigid Nonmetallic Conduit Manuel d'utilisateur télécharger pdf

Expansion

Joints for PVC

Rigid Nonmetallic

Conduit

All construction materials expand and contract

with fluctuations in temperature. These temperature

changes affect polyvinyl chloride (PVC) more than

traditional materials such as aluminum and steel. For

example, the coefficient of thermal expansion for PVC

(3.38 x 10

-5

in./in./°F) is almost three times as high as

for aluminum and six times as high as for steel.

Thermal expansion and contraction have a significant

effect on long straight runs of conduit. For this

application, expansion joints are used to accommodate changes in length. This prevents potentially

harmful thermal stresses in the conduit itself or in any supporting structures.

Expansion Fittings Required

Section 347-9 of the National Electric Code

requires that expansion joints be installed for rigid

nonmetallic conduit to compensate for thermal expansion and contraction where the length change

is anticipated to be 0.25 in. (6.36mm) or greater, in accordance with Table 347-9 of the 1999 NEC, in

a straight run between securely mounted items. Securely mounted items are boxes, cabinets, elbows,

or other conduit terminations.

When are expansion joints used?

The importance of knowing when to use an expansion joint is as important as knowing how to use

an expansion joint. Expansion joints are used in aboveground installations where temperature

changes are anticipated to exceed 25°F (14°C).

Expansion joints are usually used where the

straight run length is greater than 25 feet and

expected temperature change is greater than

60°F. Rigid PVC conduit has a coefficient of

expansion of 3.38 x 10

-5

in./in./°F. A 10 foot

length will change in length about

8" with a

change in temperature of 100°F. This equates

to more than 4 inches over a 100 foot run.

Barrel

Muzzle

Piston

Gross Automation (877) 268-3700 · www.carlonsales.com · [email protected]

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Résumé du contenu

Page 1 - Rigid Nonmetallic

Expansion Joints for PVC Rigid NonmetallicConduitAll construction materials expand and contract with fluctuations in temperature. These temperaturecha

Page 2 - (continued)

When are expansion joints used? (continued)Changes in conduit temperature outdoors can exceed 140°F considering the heat of summer and cold of winter.

Page 3 - Setting Position of Piston

Proper PositionExpansion joints are usually installed in a horizontal position. However, if they must be put in a verticalapplication, the open end sh

Page 4

Setting Expansion Joint for TemperatureWhen a more precise calculation for expansion is needed,it can be calculated as follows:1. You must determine t

Page 5 - One Expansion Joint

LocationProper placement and installation of expansion joints and conduit allow for correct functioning of theexpansion joints. For example, if one ex

Page 6 - Most Common Mistake

Use of Expansion Joints Where Concrete Encased or Direct BuriedIn normal circumstances, expansion joints are not needed with concrete encased nonmetal

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Carlon Expansion Joints for PVC Rigid Nonmetallic Conduit Manuel d'utilisateur

Naviguer en ligne ou télécharger Manuel d'utilisateur pour Équipement Carlon Expansion Joints for PVC Rigid Nonmetallic Conduit. Carlon Expansion Joints for PVC Rigid Nonmetallic Conduit User Manual Manuel d'utilisatio

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