Valve Selection Guide

Practical valve selection support for process piping applications

Step 1 of 5Line Data

Control Valve Sizing (IEC 60534)

Optional Cv calculation that validates the recommended valve type for throttling service. Skip if isolation only.

Valve body size

Defaults to line size. Override to size the valve smaller (or larger) than the line — common for control valves to keep trim in the 20–80 % opening range.

Drives the IEC 60534 equation set used.

Standard volumetric flow @ 0 °C, 1 atm.

Upstream pressure at the valve inlet. Defaults to operating pressure.

Allocated pressure drop across the valve at design flow.

Temperature at the valve inlet.

Methane 0.55, natural gas ~0.65, air 1.0.

Methane ~1.31, natural gas ~1.27, air 1.4, steam ~1.30.

Sizing Result

N/A

Pressure drop must be > 0.

Sizing not computed.

Not throttling service

Sizing is informational for non-throttling valves. The selected function is "Isolation (On/Off)". Continue without entering sizing data unless you want a Cv check.

What gets validated
Required Cv is computed and compared against typical full-open Cv for the recommended valve type and pipe size. The verdict flags under-/over-sizing and confirms whether a Globe valve is correct vs. a rotary alternative.

IEC 60534-2-1

Sizing equations for incompressible & compressible flow.

ISA 75.01

Flow equations for sizing control valves.

API 615

§6.5 — control valve selection.

Engineering Decision Support Tool - Screening / Internal Review Use unless independently validated.

Outputs are generated for engineering screening and decision support only. Final responsibility for standards compliance, engineering judgment, specification verification, and approved project use remains with the user organization and qualified reviewing engineer.