pipe fittings and valves
DESCRIPTION
basics of fittings and valvesTRANSCRIPT
Fri
ctio
n f
act
or
fF
rict
ion
fact
or
Fri
ctio
n f
act
or
Fri
ctio
n f
act
or
D V ρρρρ====Reynolds numb
De
r
V Re
ρρρρ====
µµµµ
� For laminar flows, the expression for friction factor is,
; Re16
f 0021==== ≤≤≤≤
� For turbulent flows, curves have been constructed using
; Re16
f R
00e
21==== ≤≤≤≤
� For turbulent flows, curves have been constructed using
experimental data. These curves have been fitted into
equations. These are (for hydraulically smooth pipes),equations. These are (for hydraulically smooth pipes),
0.079f
0.25Re
; ( formula)5
2100 Re 10 Blasius==== < ≤< ≤< ≤< ≤
(((( ))))
(((( ))))
Re
1 4.0 log Re f 0.4
10f; ( formula)
6230 Pran0 Re 4 10 dtl= −= −= −= − < ≤ ×< ≤ ×< ≤ ×< ≤ ×
(((( ))))(((( )))) (((( ))))
2f
3 / 2e 3 5
; where ;2 1 2
2
+ α+ α+ α+ αΨ =Ψ =Ψ =Ψ =
αααα α αα αα αα α====
+ ++ ++ ++ +αααα(((( )))) (((( ))))2
63 Barenbl
1 2
3 and ; ( 070 Re 3.2
1
tt10 a3
α αα αα αα α
< ≤< ≤< ≤< ≤
α +α +α +α + ΨΨΨΨ
+ ++ ++ ++ +
α =α =α =α = ××××
αααα
formula)6
3 Barenbl and ; ( 2 ln Re
070 Re 3.2 tt10 a3< ≤< ≤< ≤< ≤α =α =α =α = ×××× formula)
0.2f 0.046 Re ;
5 65 10 Re 10
−−−−==== × <× <× <× < ≤≤≤≤
0.125f 0.0014 +
63000 Re 3;
0. 2R
03
e1<<<< ≤ ×≤ ×≤ ×≤ ×====
Re
� For turbulent flows (rough pipes), an empirical relation is
given as,
; ( equation)
101 6.9 k D 9
3.6 log 0.4 Haaland
= − + −= − + −= − + −= − + − ; ( equation)
1 6.9 k D 9 3.6 log 0.4
10 Re 3.7fHaaland
= − + −= − + −= − + −= − + −
k4 6
4 1
protuberance (signfies roughne
and
where k = height
0
R
o
e 4 10 0 0
ss
. 5
)f
0D
×××× ××××< ≤ << ≤ << ≤ << ≤ < <<<<
protuberance (signfies roughnewhere k = height o ss)f
PIPE FITTI2GSPIPE FITTI2GS
450 elbow 900 elbow 900
square elbow
wheelwheel
gland
spindle
bonnetgland
packing
bonnet
bodybody
disk
Dh DD
h