8
Know-how makes the difference
B-V-NOTCH-UK-02-2014 REV. C
An
Company
DN100FB - 30
o
V-NOTCH / 90% OPEN / SATURATED STEAM [KG/H]
bara
D
P
0,1
D
P
0,2
D
P
0,3
D
P
0,4
D
P
0,5
D
P
0,6
D
P
0,7
D
P
0,8
D
P
0,9
D
P
1,0
D
P
1,5
D
P
2,0
1,2
908 1284
CRITICAL FLOW
1,5
1025 1450 1776 2050 2292
P2
abs
≤ (P1
abs
x0.58)
2,0
1170 1655 2027 2341 2617 2867 3097 3311 3511 3701
2,5
1301 1840 2254 2603 2910 3188 3443 3681 3904 4115
3,0
1414 1999 2449 2828 3161 3463 3741 3999 4241 4471 5476
3,5
1531 2166 2652 3063 3424 3751 4051 4331 4594 4842 5931
4,0
1628 2302 2820 3256 3640 3988 4307 4605 4884 5148 6305 7281
4,5
1724 2439 2987 3449 3856 4224 4563 4878 5173 5453 6679 7712
5,0
1815 2567 3144 3631 4059 4447 4803 5134 5446 5740 7031 8118
5,5
1894 2678 3280 3787 4234 4639 5010 5356 5681 5988 7334 8469
6,0
1952 2761 3381 3904 4365 4781 5164 5521 5856 6173 7560 8730
6,5
2050 2900 3551 4101 4585 5023 5425 5800 6151 6484 7941 9170
7,0
2125 3005 3681 4250 4752 5205 5622 6011 6375 6720 8230 9503
V-NOTCH SIZE SELECTION GUIDE - SATURATED STEAM
FLOW VALUES AT 90% OPEN VALVE
DN100FB - 60
o
V-NOTCH / 90% OPEN / SATURATED STEAM [KG/H]
bara
D
P
0,1
D
P
0,2
D
P
0,3
D
P
0,4
D
P
0,5
D
P
0,6
D
P
0,7
D
P
0,8
D
P
0,9
D
P
1,0
D
P
1,5
D
P
2,0
1,2
1480 2093
CRITICAL FLOW
1,5
1672 2364 2896 3344 3739
P2
abs
≤ (P1
abs
x0.58)
2,0
1909 2699 3306 3817 4268 4675 5050 5399 5726 6036
2,5
2122 3001 3676 4244 4745 5198 5615 6002 6366 6711
3,0
2306 3261 3993 4611 5155 5647 6100 6521 6917 7291 8929
3,5
2497 3531 4325 4994 5584 6117 6607 7063 7491 7897 9671
4,0
2655 3755 4599 5310 5937 6503 7024 7509 7965 8396
10283 11873
4,5
2812 3977 4871 5624 6288 6889 7440 7954 8437 8893
10892 12577
5,0
2960 4187 5127 5921 6620 7251 7832 8373 8881 9361
11465 13239
5,5
3088 4367 5349 6176 6905 7564 8171 8735 9265 9766
11960 13811
6,0
3183 4502 5514 6366 7118 7797 8422 9004 9550
10066 12329 14236
6,5
3344 4729 5792 6688 7477 8191 8847 9458
10031 10574 12951 14954
7,0
3465 4901 6002 6931 7749 8489 9169 9802
10396 10959 13422 15498
Flow values for steam are based on following:
Saturated steam, 1-7bar
absolut
, Not critical flow. 0,1-2bar diff pressure.
Valve is
90%
OPEN (
90-100% OPEN = 20-30% more flow capacity
)
Step 1:
Choose the steam pressure from left column. (Bar absolut)
Step 2:
Choose the differential pressure from top row.
Step 3:
You now have the flowrate (kg/h), for the specific V-notch size at
90% open valve.
(Please look at example below)
Choosing the correct size V-notch will give you the best possible
regulation and maximum lifetime of valve.
Due to velocity and noise, DVC does not advice a higher differential pressure
than 5bar maximum for regulation.
Max operational pressure for regulation of saturated steam is:
SEAT MATERIAL: PTFE + 25%C = 7bar
SEAT MATERIAL: PEEK
= 9bar
Constantly regulating at 15-25% OPEN valve will reduce lifetime of valve seats.
Other sizes valves (5”-6”) and V-notch (90
o
) on request.
[kg/h]
[m3/kg]
Kv = G
31,6
V1P
P
46,2Kg/h
...DVC has made the calculations...
...you get all the benefits and save time...
EXAMPLE:
Flow:
150kg/h
Upstream pressure:
5 bara
D
P:
0,2bar
DN20 - 60
o
V-NOTCH
bara
D
P
0,1
D
P
0,2
D
P
0,3
4,0
113,4
160,4
196,5
4,5
120,2
169,9
208,1
5,0
126,5
178,9
219,1
5,5
132,0
186,6
228,6
6,0
136,0
192,4
235,6
1
st
choise
Left column bara = 5,0bar absolut
upper row
D
P = 0,2bar
nearest value above = 178,9kg/h (90% OPEN valve)
Valve = DN20FB 60
o
V-notch
2
nd
choise
Valve = DN15FB 60
o
V-notch (Costumers choise due to piping)
Nearest flow above = 160,8kg/h
D
P = 0,6....0,7bar (accepting a bigger pressuredrop reduces valve size)
DN15 - 60
o
V-NOTCH
bara
D
P
0,6
D
P
0,7
D
P
0,8
4,0
133,5
144,2
154,2
4,5
141,4
152,8
163,3
5,0
148,9
160,8
171,9
5,5
155,3
167,8
179,3
6,0
160,1
172,9
184,9
Bara
(Absolut pressure)
VACUUM
~1,013Bar
(Atmospheric pressure)
Baro
(Pressure over Atmosphere)
4,013bar
5,000bar
V-NOTCH BALL - SIZING - SATURATED STEAM
