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Piping System Friction
Piping System Friction 65

Table 3.14 Data Summary of Test Data for Ells, Reducers, and Expansions

USU USU USU
Past 4 fps 8 fps 12 fps
2′′ S.R. Ell (R/D = 1). Thread 0.60 to 1.0 (1.0)* 0.60 0.68 0.736
4′′ S.R. Ell (R/D = 1) Weld 0.30 to 0.34 0.37 0.34 0.33
1′′ L.R. Ell (R/D = 1.5) Weld 0.39 to 1.0 ------ ------ ------
2′′ L.R. Ell (R/D = 1.5) Weld 0.50 to 0.7 ------ ------ ------
4′′ L.R. Ell (R/D = 1.5) Weld 0.22 to 0.33 (.22)* 0.26 0.24 0.23
6′′ L.R. Ell (R/D = 1.5) Weld 0.25 0.26 0.24 0.24 †
8′′ L.R. Ell (R/D = 1.5) Weld 0.20 to 0.26 0.23 0.20 0.19 †
10′′ L.R. Ell (R/D = 1.5) Weld 0.17 0.21 0.17 0.16 †
12′′ L.R. Ell (R/D = 1.5) Weld 0.16 0.17 0.17 0.17
16′′ L.R. Ell (R/D = 1.5) Weld 0.12 0.12 0.2 0.11
20′′ L.R. Ell (R/D = 1.5) Weld 0.09 0.12 0.10 0.10
24′′ L.R. Ell (R/D = 1.5) Weld 0.07 0.098 0.089 0.089
Reducer (2′′ × 1.5′′) Thread ------ 0.53 0.28 0.20
Reducer (4′′ × 3′′) Weld 0.22 0.23 0.14 0.10
Reducer (12′′ × 10′′) Weld ------ 0.14 0.14 0.14
Reducer (16′′ × 12′′) Weld ------ 0.17 0.16 0.17
Reducer (20′′ × 16′′) Weld ------ 0.16 0.13 0.13
Reducer (24′′ × 20′′) Weld ------ 0.053 0.053 0.055
Expansion (1.5′′ × 2′′) Thread ------ 0.16 0.13 0.02
Expansion (3′′ × 4′′) Weld ------ 0.11 0.11 0.11
Expansion (10′′ × 12′′) Weld ------ 0.11 0.11 0.11
Expansion (12′′ × 16′′) Weld ------ 0.073 0.076 0.073
Expansion (16′′ × 20′′) Weld ------ 0.024 0.021 0.022
Expansion (20′′ × 24′′) Weld ------ 0.020 0.023 0.020
NOTE: Past (published data by Freeman, Crane, Hydraulics Institute)
USU (Utah Sate University Data)
S.R. short radius or regular Ell; L.R. = long radius Ell
( )* Data published in ASHRAE Fundamentals.
† Data received from ASHRAE Research Project No. 1116 RP by University of Minnesota.
SOURCE: Copyright 1999. American Society of Heating, Refrigerating and Air-Conditioning
Engineers, Inc. www.ashrae.org. Reprinted by permission from ASHRAE Transactions,
Vol. 105, Part 1.

energy savings for factory assembled pumping systems by having
closely connected pipe fittings.
1116 RP. These tests on 6, 8, and 10 in steel pipe fittings indicate
the same findings as those for 968 RP and 1034 RP, namely, that
the K factors for them vary with the velocity of the water.
All of the above projects were for steel fittings. This significant
new fact that the K factor varies with the velocity of the water in
the fittings is shown in Fig. 3.6 and 3.7. Publication of tables simi-
lar to 3.12 is needed for all pipe fittings to insure that the K factors
are accurate.
1193 RP. This project for plastic pipe fittings was quite significant,
as this may be the first precise laboratory tests for such fittings.

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