8.3.2: Minor Losses Due to Pipeline Fittings
- Page ID
- 44579
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Head or pressure losses also occur in the fittings used in the pipeline system. These head losses are due to friction in the fitting, plus losses resulting from turbulence and changes in the direction of flow. Head loss in fittings, valves, etc., can be described by:
\(h_m = K \left(\dfrac{{V_m}^2}{2 g}\right) \) (8.12)
where: hm = head loss in fitting (ft),
K = resistance coefficient for fitting, and
Vm = velocity of flow (ft/s).
Resistance coefficients for various types of fittings and valves are given in Table 8.4.
|
Fitting or Valve |
Standard Pipe Nominal Diameter 3 in (76.2 mm) |
Standard Pipe Nominal Diameter 4 in (101.6 mm) |
Standard Pipe Nominal Diameter 5 in (127.0 mm) |
Standard Pipe Nominal Diameter 6 in (152.4 mm) |
Standard Pipe Nominal Diameter 7 in (177.8 mm) |
Standard Pipe Nominal Diameter 8 in (203.2 mm) |
Standard Pipe Nominal Diameter 10 in (254 mm) |
|---|---|---|---|---|---|---|---|
| Bends | |||||||
| Return flanged | 0.33 | 0.30 | 0.29 | 0.28 | 0.27 | 0.25 | 0.24 |
| Return screwed | 0.80 | 0.70 | |||||
| Elbows | |||||||
| Regular flanged 90° | 0.34 | 0.31 | 0.30 | 0.28 | 0.27 | 0.26 | 0.25 |
| Long radius flanged 90° | 0.25 | 0.22 | 0.20 | 0.18 | 0.17 | 0.15 | 0.14 |
| Long radius flanged 45° | 0.19 | 0.18 | 0.18 | 0.17 | 0.17 | 0.17 | 0.16 |
| Regular screwed 90° | 0.80 | 0.70 | |||||
| Long radius screwed 90° | 0.30 | 0.23 | |||||
| Regular screwed 45° | 0.30 | 0.28 | |||||
| Tees | |||||||
| Flanged line flow | 0.16 | 0.14 | 0.13 | 0.12 | 0.11 | 0.10 | 0.09 |
| Flanged branch flow | 0.73 | 0.68 | 0.65 | 0.60 | 0.58 | 0.56 | 0.52 |
| Screwed line flow | 0.90 | 0.90 | |||||
| Screwed branch flow | 1.20 | 1.10 | |||||
| Valves | |||||||
| Globe flanged | 7.0 | 6.3 | 6.0 | 5.8 | 5.7 | 5.6 | 5.5 |
| Globe screwed | 6.0 | 5.7 | |||||
| Gate flanged | 0.21 | 0.16 | 0.13 | 0.11 | 0.09 | 0.075 | 0.06 |
| Gate screwed | 0.14 | 0.12 | |||||
| Swing check flanged | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 |
| Swing check screwed | 2.1 | 2.0 | |||||
| Angle flanged | 2.2 | 2.1 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 |
| Angle screwed | 1.3 | 1.0 | |||||
| Foot | 0.80 | 0.80 | 0.80 | 0.80 | 0.80 | 0.80 | 0.80 |
| Strainers | |||||||
| Basket type | 1.25 | 1.05 | 0.95 | 0.85 | 0.80 | 0.75 | 0.67 |