Gate valves in a straight tube (without a recess for Diagram
the valve disk);Re = woDh/v > lo4 [13, 15,33,43] 9-5
Circular cross section
see the curves =f(h/Do or h/ao)
Rectangular cross section
Dh =-4Fo
no
Values of 5- for single disk gate valves (graph a)
Fh/F,, for circular cross section
- -
Circular cross section (Do = 25 mm)
Curve 1 - - 35.0 10.0 4.60 2.06 0.98 0.44 0.17 0.06
Rectangular cross section
0.5 (25 X 50). Curve 2 193 - 44.5 17.8 8.12 4.02 2.08 0.95 0.39 0.09
0.5(150X300mm).Curve3 105 51.5 30.6 13.5 6.85 3.34 1.73 0.83 0.32 0.09
1.0 (150 X 150mm). Curve 4 155 72.0 42.3 18.5 8.78 4.54 2.43 1.23 0.55 0.17
1.0 (225 X 150 mm). Curve 5 330 122 58.2 19.6 9.10 4.68 2.66 1.23 0.47 0.11
2.0 (300 X 150 mm). Curve 6 203 86.5 48.7 17.9 8.78 4.47 2.25 1.12 0.51 0.13
(Continued)
Gate valves in a straight tube (without,,a recess for Diagram
the valve disk); Re = woDh/u > lo4 [13,15,33,43] 9-5
-- -
Values of for two-part disk gate valve of rectangular cross section (graph b) -
hla,
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0.5 (150 x 300 mm). Curve 1 112 30.6 13.1 6.64 3.26 1.52 0.71 0.28 0.07
1.0 (150 x 150 mm). Curve 2 95.3 31.7 14.1 6.95 3.63 1.83 0.91 0.36 0.08
1.5 (225 x 150 mm). Curve 3 287 50.1 17.9 8.31 4.22 2.22 1.02 0.39 0.10
2.0 (300 X 160 mm). Curve 4 215 48.7 18.5 8.48 4.17 2.14 1.02 0.42 0.12
Plane-parallel gate valves of the Ludlow type, with a recess for the valve disk, Diagram
in a straight tube of a circular cross section; Re = woDo/v > lo4 1331 96
1. Gate valve in the system:
see the curves = f ( h / ~ , )
2. Exit gate valve
Values of 5 -
Position of the gate hlDo
valve 0.10 0.15 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.0
With a recess for the valve disk (graph a)
Inthesystem(thegate 200 77.0 33.0 11.0 4.70 2.35 1.23 0.67 0.31 0.11 0.05
valve is followed by a
straight tube). Curve 1
Diagram
9-6
h/D,
Position o f the gate
valve 0.10 0.15 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.0
Terminal (gate valve 200 64.0 36.0 14.2 7.10 3.85 2.30 1.40 0.75 0.21 0.11
at the exit), Curve 2
With a hollow ring on the valve (graph b)
Inthesystem,Curvel 400 - 43.0 12.5 5.30 2.48 1.19 0.51 0.22 0.08 0.03
Terminal, Curve 2 3900 - 260 70.0 22.0 87.0 4.00 1.85 0.78 0.15 0
Plane-parallel gate valves of the Ludlow type, with a recess
Diagram
for the valve disk, in a converging-divergingtransition piece
9-7
of circular cross section; Re = w o D o / v> lo4 [12, 341
1. Asymmetric transition
C(
Values of 5 for an asymmetric transitiont
1.5 (curve 1) 200 77.0 34.0 12.5 6.50 3.65 2.15 1.35 0.71 0.24 0.07
1.25(cume2) 200 77.0 33.0 12.5 6.10 3.15 1.85 1.10 0.58 0.18 0.06
?values of 5 for a gate valve in a converging-diverging transition piece do not allow for the losses in
these transition pieces.
2. Symmetrical transition.$ Complete opening.
D o , mm 300 300 200 250
DclDo 0.67 0.67 0.75 0.80
LIDo 2.50 1.68 1.33 1.50
5 (without a guide pipe) 0.30 0.36 0.19 0.16
5 (with a guide pipe) 0.26 0.28 0.18 0.15
*values of 5 of the gate valve with symmetrical transi-
tion allow for the construction and subsequent expansion
losses; wc is the velocity in the narrow section of the gate
valve, m/s.
Rolling sealgates; Re = w,Do/v > lo4 Diagram
[33,341 9-8
1. Seal gate in the system:
f=- , see the curves f =f(6)
pw,Z/2
2. Exit seal gate: 3. Seal gate in a transition piece: fo, = Ap/(pw,2/2)= 5 + f t r
where ftr is determined as f from Diagrams 5-24 and 5-22
ap
ftot=-=f+ 1
PW,Z/~
Values of 5
D l ID, ;place of 6, degrees
installation of
the breechlock 0 10 20 30 40 50 60 70 80 90 100 115
Straight flow (direction a-c; graph a)
1.0; in the system
(I, f' > 0);curve 1 0.02 0.08 0.36 1.08 2.50 6.80 16.9 44.0 108 277 540 620
1.0; at exit (1, = 0 ) ;
curve 2 0.03 0.17 0.90 2.13 4.70 9.50 21.6 49.0 112 277 540 620
1.25-1.5;in a
converging-diverging
transition piece
(2, 0 > 0);curve 3 0.02 0.13 0.60 1.60 3.70 7.5 18.0 44.0 106 277 540 620
Reverse flow (direction b-a; graph b)
1.O; in the system
(I, >O);curvel 0.01 0.19 0.70 1.70 3.8 7.70 15.8 35.0 81.0 191 549 820
1.0; at exit (1, = 0 ) ;
curve 2 0.03 0.24 1.00 2.60 5.50 10.8 21.5 44.0 92.0 191 540 820
or I , , see scheme a of Diagram 9-19.
s ~ h values
e of f of the gate valve in a convergingdiverging transition piece d o not allow for the
losses in this piece (see scheme 1 of Diagram 9-19).
Circular outlet seal gates; Re = woDo/v> lo4 Diagram
[33,341 9-9
1. With a thrust cone
2. With a streamlined thrust element
see the curves f = f(s/D0) of graph a. for f , see the curves < =f
3. Discharge tube is contracted at the exit
at complete opening f = 0.3
Values of 5 (scheme 1, graph a)
1.5 (curve 1) 1.80 1.50 1.35 1.30 1.26
1.75-2.0 (curve 2) 1.44 1.15 0.97 0.88 0.82
3.0 (curve 3) 1.58 1.20 1.05 0.95 0.90
m (curve 4) 1.83 1.50 1.30 1.19 1.12
Diagram
9-9
Values of 5 (scheme 2, graph b)
S
Do
-
Dl
Do 0.1 0.2 0.3 0.4 0.5 0.7 1.O
1.5 (curve 1) 13.0 3.10 1.04 0.5 1 0.39 0.33 0.32
1.75 (curve 2) 13.8 3.08 1.45 0.85 0.59 0.41 0.35
2.0 (curve 3) 9.42 3.50 1.50 1.01 0.76 0.58 0.5 1
2.5 (curve 4) 11.9 4.31 2.17 1.44 1.10 0.84 0.76
3.0 (curve 5) 16.0 4.92 2.5 1 1.66 1.28 1.OO 0.86
