61
© 2011 Schneider Electric. All rights reserved.
Valve and Actuator Catalogue
Schneider Electric
Telephone Europe: Malm
ö
, Sweden +46 40 38 68 50 Telephone Asia Pacific: Singapore +65 6776 3166
VACAT_July2011 July 2011
ao
SteamValve Sizing Chart
Flow rate, Saturated steam Kg/h
Valve pressure drop, p (load pressure),
kPa
Absolute Steam
Pressure, kPa
1
2
3
5
4
Example for saturated Steam:
Flow rate, (G)
4700 Kg/h
Abs. Pressure upstream (p1)
850 kPa
Load Pressure (
∆
Pv)
160 kPa
Mark the point of intersection [3] between the line originating from the absolute
upstream pressure [1] and the inclined line corresponding to the load pressure (valve
pressure drop)[2].
Identify the point of intersection between point [3] found above and the flow rate of
Saturated steam [4]
The last found point would corresponds to a valve with a Kvs of 63 [5]
Key:
Kvs = Valve flow co-efficient,
(Control valve fully open).
G = Mass flow rate (Kg/h)
v
2
= Specific volume (from steam
table) for p
2
and t
1
condition
V* = Specific volume (from steam
table) for and t
1
condition
p1 = pressure before valve
p2 = pressure after valve
∆
p = Valve Pressure drop (bar)
