Control valves

Pressure reducing/surplussing valves

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4.6.57

Sizing and selection for steam applications

The sizing chart below can be used to determine the Kv value of the valve for steam applications by plotting:

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Upstream pressure.

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Maximum valve pressure drop.

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Maximum steam load.

Where the Kv value is known, the chart can be used to determine pressure drop across the valve for any

given flowrate.

Kv sizing example:

Maximum flowrate 1500 kg/h

Upstream pressure 9 bar g (10 abs)

Maximum pressure drop 0.5 bar

Draw a horizontal line A - B at 10 abs.

At intersection with 0.5 pressure drop draw a vertical line C - D.

Draw a vertical line E - F at 1500 kg/h.

At intersection G, read the required Kv = 28.

Valve size required DN50 having the next highest Kv of 40.

Example

line

A

Note: The sizing chart is empirical and should not be used for critical applications.

TI-P206-01 CH Issue 12

DEP4 Cast Steel Excess Pressure Valve

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