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45 Elbow

A 45 degree elbow "long radius" (LR) has a centerline curvature equal to 1-1/2 times the nominal pipe size (NPS) for 3/4 inch and larger sizes.

A 45 degree elbow "long radius, long tangent" is a long radius (LR) with the centerline curvature equal to 1-1/2 times the nominal pipe size (NPS) and a straight extension at both ends (long tangent) for 2 inch and larger sizes. Tangent elbows provide a straight length at the end to accept a Slip-on Flange. The tangent end for the flange is not beveled.

A 45 degree elbow "three radius" is a long radius (LR) with the centerline curvature equal to 3 times the nominal pipe size (NPS).

90 Elbow

A 90 degree elbow "long radius" (LR) has a centerline curvature equal to 1-1/2 times the nominal pipe size (NPS) for 3/4 inch and larger sizes.

A 90 degree elbow "short radius" (SR) has a centerline curvature equal to 1 times the nominal pipe size (NPS) for 1 inch and larger sizes.

A 90 degree elbow "long radius, long tangent" is a long radius (LR) with the centerline curvature equal to 1-1/2 times the nominal pipe size (NPS) and a straight extension at both ends (long tangent) for 2 inch and larger sizes. Tangent elbows provide a straight length at the end to accept a Slip-on Flange. The tangent end for the flange is not beveled.

A 90 degree elbow "short radius, long tangent" is a short radius (SR) with the centerline curvature equal to 1 times the nominal pipe size (NPS) and a straight extension at both ends (long tangent) for 8 inch and larger sizes. Tangent elbows provide a straight length at the end to accept a Slip-on Flange. The tangent end for the flange is not beveled.

A 90 degree elbow "three radius" is a long radius (LR) with the centerline curvature equal to 3 times the nominal pipe size (NPS).

180 Return

A 180 degree return "long radius" (LR) has a centerline curvature equal to 1-1/2 times the nominal pipe size (NPS) for 3/4 inch and larger sizes.

A 180 degree return "short radius" (SR) has a centerline curvature equal to 1 times the nominal pipe size (NPS) for 1 inch and larger sizes.

Mitered Elbow

A mitered elbow is fabricated from pipe and is not a fitting. A miter is used for larger pipes, where pressure drop is not important and cost is a factor. A 2 piece 90 degree miter has 4 to 6 times hydraulic resistance of the corresponding long radius elbow. A 3 piece, 90 degree miter has about double the resistance. The normal number of miter pieces used are 3, 4, or 5.

Street Ell

A street ell is an elbow that is threaded with a female connection on one side and a male connection on the other. This is usually used when there are space constraints since it does not need a nipple attached to the output to convert the sex of the connection. A "street ell" may have gotten it's name because it describes a 90 degree fitting particularly useful in tight, street ditches. When installing water pipes under a street, or from a water service, again under the street, into a home or business, this street ell allows one to change pipe direction with one less fitting, and in less space, than with a standard ell.

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