Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Water Control Valves - K_v Calculation

Designing water process control valves and their K_v values.

Sponsored Links

The table below can be used to estimate the K_v values for process control valves used in water systems.

Go to the left column and select the pressure drop for the valve
Go right in table close to the actual water flow. Interpolate to find the approximately K_v value

For full table - rotate the screen!

K_v
Pressure drop		Water flow (kg/h)
Pressure drop		36	72	108	144	180	360	720	1080	1440	1800	3600
(kPa)	(bar)	Water flow (kg/s)
(kPa)	(bar)	0.01	0.02	0.03	0.04	0.05	0.1	0.2	0.3	0.4	0.5	1
1	0.01	0.36	0.72	1.1	1.4	1.8	3.6	7.2	10.8	14.4	18.0	36.0
2	0.02	0.25	0.51	0.76	1.0	1.3	2.6	5.1	7.6	10.2	12.7	25.5
3	0.03	0.21	0.42	0.62	0.83	1.0	2.1	4.2	6.2	8.3	10.4	20.8
4	0.04	0.18	0.36	0.54	0.72	0.90	1.8	3.6	5.4	7.2	9.0	18.0
5	0.05	0.16	0.32	0.48	0.64	0.80	1.6	3.2	4.8	6.4	8.1	16.1
10	0.1	0.11	0.23	0.34	0.46	0.57	1.1	2.3	3.4	4.6	5.7	11.4
20	0.2	0.08	0.16	0.24	0.32	0.40	0.80	1.6	2.4	3.2	4.0	8.1
30	0.3	0.07	0.13	0.2	0.26	0.33	0.66	1.3	2.0	2.6	3.3	6.6
40	0.4	0.06	0.11	0.17	0.23	0.28	0.57	1.1	1.7	2.3	2.9	5.7
50	0.5	0.05	0.10	0.15	0.20	0.25	0.51	1.0	1.5	2.0	2.6	5.1
100	1	0.04	0.07	0.11	0.14	0.18	0.36	0.72	1.1	1.4	1.8	3.6
200	2	0.03	0.05	0.08	0.10	0.13	0.25	0.51	0.76	1.0	1.3	2.6
300	3	0.02	0.04	0.06	0.08	0.10	0.21	0.42	0.62	0.83	1.0	2.1
400	4	0.02	0.04	0.05	0.07	0.09	0.18	0.36	0.54	0.72	0.9	1.8
500	5	0.02	0.03	0.05	0.06	0.08	0.16	0.32	0.48	0.64	0.8	1.6
1000	10	0.01	0.02	0.03	0.05	0.06	0.11	0.23	0.34	0.46	0.57	1.1
2000	20	0.01	0.02	0.02	0.03	0.04	0.08	0.16	0.24	0.32	0.40	0.80
3000	30	0.01	0.01	0.02	0.03	0.03	0.07	0.13	0.20	0.26	0.33	0.66
4000	40	0.01	0.01	0.02	0.02	0.03	0.06	0.11	0.17	0.23	0.28	0.57

For full table - rotate the screen!

K_v
Pressure drop		Water flow (kg/h)
Pressure drop		7200	10800	14400	18000	36000	72000	108000	144000	180000	360000	720000
(kPa)	(bar)	Water flow (kg/s)
(kPa)	(bar)	2	3	4	5	10	20	30	40	50	100	200
1	0.01	72.0	108	144	180	360	720	1080	1440	1800	3600	7200
2	0.02	50.9	76.4	102	127	254	509	763	1019	1273	2546	5091
3	0.03	41.6	62.4	83.1	103	207	415	623	831	1039	2078	4157
4	0.04	36.0	54.0	72.0	90.0	180	360	540	720	900	1800	3600
5	0.05	32.2	48.3	64.4	80.5	161	321	483	644	805	1610	3220
10	0.1	22.8	34.2	45.5	56.9	113	227	342	455	569	1138	2277
20	0.2	16.1	24.2	32.2	40.3	80.5	161	242	322	402	805	1610
30	0.3	13.2	19.7	26.3	32.9	65.7	131	197	263	329	657	1315
40	0.4	11.4	17.1	22.8	28.5	56.9	114	171	228	285	569	1138
50	0.5	10.2	15.3	20.4	25.5	50.9	102	153	204	255	509	1018
100	1	7.2	10.8	14.4	18.0	36.0	72.0	108	144	180	360	720
200	2	5.1	7.6	10.2	12.7	25.5	50.9	76.4	102	127	255	509
300	3	4.2	6.2	8.3	10.4	20.8	41.6	62.4	83.1	104	208	416
400	4	3.6	5.4	7.2	9.0	18.0	36.0	54.0	72.0	90.0	180	360
500	5	3.2	4.8	6.4	8.1	16.1	32.2	48.3	64.4	80.5	161	322
1000	10	2.3	3.4	4.6	5.7	11.4	22.8	34.2	45.5	56.9	114	228
2000	20	1.6	2.4	3.2	4.0	8.1	16.1	24.2	32.2	40.3	80.5	161
3000	30	1.3	2.0	2.6	3.3	6.6	13.2	19.7	26.3	32.9	65.7	131
4000	40	1.1	1.7	2.3	2.9	5.7	11.4	17.1	22.8	28.5	56.9	114

Download Water Flow Kv Diagram

Example - K_v for a Water Control Valve

For a water control valve with

pressure drop 2 bar
water flow 1 kg/s

- the K_v value should be approximately 2.6 according the table above.

K_v can be calculated as:

K_v = q / (dp)^1/2 (1)

where

K_v = K_v value

q = water flow (m³/h)

dp = pressure drop (bar)

Sponsored Links

Related Topics

Control Valves - Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators and positioners
Process Control - Instrumentation and process control systems - design and documentation.
Water Systems - Hot and cold water service systems - design properties, capacities, sizing and more.

Related Documents

Ball Valves - Flow Coefficients C_v - Flow coefficients - C_v - for typical ball valves - reduced and full bore.
Butterfly Valves - Flow Coefficients C_v - Typical flow coefficients - C_v - for butterfly valves.
Control Valves - Adding Flow Coefficients for Valves in Series or Parallel - How to add flow coefficients for control valves in series or parallel.
Control Valves - Leakage Classification - Seat leakage classification through control valves.
Flow Coefficient C_v vs. Flow Factor K_v - Comparing flow coefficients C_v to flow factors K_v.
Liquid, Steam and Gas - Flow Coefficients C_v - Calculate flow coefficients for the design of control valves - Imperial units.
Liquid, Steam and Gas - Flow Factor K_v - Calculate flow factor K_v for liquids, steam and gases - metric units.
Process Controllers - P, PI & PID - Proportional, integrating and derivative process controllers.
Straight Through Diaphragm Valves - Flow Coefficients - Flow coefficients - C_v - and flow factors - K_v - for straight through diaphragm valves.
Valve Authority - The valve authority expresses the ratio between pressure drop across the control valve compared to total pressure drop across the whole system.
Water Control Valves - Flow Factor K_v Diagram - Sizing of water control valves - SI units
Water Control Valves - Flow Coefficient C_v Diagram - Sizing of water control valves - Imperial units.
Weir Diaphragm Valves - Flow Coefficients and Flow Factors - Typical flow coefficients - C_v - and flow factors - K_v - for weir diaphragm valves.

Sponsored Links

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!

Translate

About the Engineering ToolBox!

Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.

Advertise in the ToolBox

If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. You can target the Engineering ToolBox by using AdWords Managed Placements.

Citation

This page can be cited as

Engineering ToolBox, (2003). Water Control Valves - K_v Calculation. [online] Available at: https://www.engineeringtoolbox.com/control-valves-water-d_265.html [Accessed Day Mo. Year].

Modify access date.

close

3D Engineering ToolBox - draw and model technical applications!

2D Engineering ToolBox - create and share online diagram drawing templates!

Engineering ToolBox Apps - mobile online and offline engineering applications!

Scientific Online Calculator

Scientific Calculator

3 10

Sponsored Links