Flowmetering
Target flowmeters
3.3.5
Sizing the TVA flowmeter for saturated steam (kg/h) (Horizontal orientation)
Maximum flowrates in kg/h at different pressures (bar g).
Notes:
1 - Maximum steam flowrates are calculated at maximum differential pressure.
2 - For vertical capacities please contact Spirax Sarco.
3 - The table below is a guide only.
4 - For superheated capacities please use the sizing software on our website www.spiraxsarco.com
Size
Steam pressure bar g
1
3
5
7
10
12
15
20
25
30
32
bar g
kg/h
kg/h
kg/h
kg/h
kg/h
kg/h
DN50 Q
E
= 300
DN80 Q
E
= 770
DN100 Q
E
=1200
Max.flow
619
859
1042 1196 1395 1513 1676 1918 2135 2335 2409
Min.flow
12
17
21
24
28
30
33
38
43
47
60
Max.flow 1588 2204 2674 3070 3581 3885 4301 4922 5480 5994 6183
Min.flo
w
3
2
4
4
5
3
6
1
7
2
7
8
8
6
9
8
11
0
12
0
128
Max.flow 2475 3435 4167 4784 5581 6054 6703 7671 8540 9341 9637
Min.flow
49
69
83
96
112
121
134
153
171
187
192
Safety information, installation and maintenance
For full details see the Installation and Maintenance Instructions (IM-P192-02) supplied with the product.
The following main points are given for guidance only:
1. The TVA flowmeter should be mounted with a minimum of 6 straight pipe diameters upstream and 3 downstream. No valves, fittings or
cross sectional changes are permitted within these pipe lengths. Where an increase in nominal pipe diameter is required, upstream of the
flowmeter, the length of straight pipe should be increased to 12 diameters. Similarly, where a Spirax Sarco TVA is installed downstream
of two 90° bends in two planes, a pressure reducing valve or a partly open valve, 12 upstream pipe diameters should be allowed.
2. It is important that the internal upstream and downstream diameters of pipe are smooth. Ideally seamless pipes should be used and
there should be no intrusive weld beads on the internal diameter. It is also recommended that slip-on flanges are used to avoid this.
3. Care should be taken to install the TVA
flowmeter concentrically in the line. If this is not done, flow measurement errors may occur.
4. The TVA flowmeter can be installed in any orientation up to a line pressure of 7 bar g whilst conditions are saturated. When conditions
are superheated then the TVA flowmeter can only be installed in horizontal pipework, with the electronics below the pipeline.
5. As for all steam
flowmetering installations, good basic steam engineering practices should be followed:
-
Correct line drainage through adequate trapping.
-
Good alignment and support of associated pipework.
-
Line size changes achieved by the use of eccentric reducers.
-
Do not lag (insulate) the TVA body or the mating flanges.
6. The TVA flowmeter must not be installed outside where it can be subjected to driving rain or where it is liable to freeze.
How to order
Saturated Service Example: 1 off Spirax Sarco DN100 TVA flowmeter for installation between EN 1092 PN40 flanges for use on saturated
steam at 10 bar g - Maximum flow 5 581 kg/h.
Superheated Service Example: 1 off Spirax Sarco DN100 TVA flowmeter, Pressure sensing kit and 'U' syphon, for installation between
EN 1092 PN40 flanges for use on superheated steam at 10 bar g.
Note: For details of the optional remote display see the relevant Spirax Sarco M750 literature.
Spare parts and accessories
-
Spare electronics front panel (with standard RS 232C Communications)
-
Spare electronics front panel (with RS485 Communications converter)
Page 4 of 4
TI-P192-01 MI Issue 3
TVA Flowmeter for Saturated and Superheated Steam Service
