CONVAL vs Fisher Specification Manager vs SAMSON: When Each Earns Its Keep

TL;DR: Control valve sizing tools fall into two camps. A manufacturer's own tool, such as Emerson's Fisher Specification Manager or SAMSON's c-SAM, sizes and specifies that manufacturer's valves and nothing else. CONVAL 12 from F.I.R.S.T. GmbH is vendor-neutral by design: it sizes any manufacturer's valve, extends across orifice plates, thermowells, relief valves and more in the same licence, and keeps every calculation traceable to a named published standard. If your job is to specify the right valve rather than to configure a valve already chosen from one brand, the vendor-neutral tool is the one that protects the integrity of your work.

Why the Comparison Matters

Process and instrumentation engineers are regularly asked which calculation tool they use for control valve sizing. The honest answer is that the choice is not purely technical: it reflects whether the engineer's role is to specify any suitable valve from any manufacturer, or to configure and document a valve that has already been chosen from a particular range.

Those are different jobs, and independent specification is the harder one. A tool tied to a single manufacturer's catalogue cannot do it, however well built that tool is.

The three tools examined here represent the main camps:

• CONVAL 12 (F.I.R.S.T. GmbH, Germany): vendor-independent, covers a broad range of instrumentation and process components beyond valves
• Fisher Specification Manager (Emerson): built for Fisher and Baumann control valves only
• SAMSON c-SAM (SAMSON AG, Germany): built around SAMSON's own valve series, and recommends from SAMSON's catalogue

CONVAL 12: The Vendor-Independent Toolkit

CONVAL has been in industrial use since 1989. The developer, F.I.R.S.T. GmbH of Wermelskirchen, Germany, built it specifically to give instrumentation and process engineers a calculation environment that is "absolutely independent from device manufacturers, without having to forego specific manufacturer data" (F.I.R.S.T. GmbH, 2024). The current release is CONVAL 12, now in service release 12.2.

What It Covers

Control valve sizing is the centrepiece, but CONVAL's scope extends well beyond it. In a single licence, engineers can size and verify:

• Control valves (including two-phase flow at the inlet, steam conditioning units, and steam cooling valves), calculated to IEC 60534-2-1, IEC 60534-8-3/4, ISA 75.01, and VDMA 24422
• Actuated valve assemblies and part-turn actuators, to ISO 5115 and ISO 5211
• Differential pressure flow elements (orifice plates, nozzles, venturi tubes, annubars, cone and wedge meters), calculated to ISO 5167 parts 1-6 (2022 editions), ASME MFC-3M, AGA 3, and over twenty further standards
• Restriction orifice plates, including multi-hole and multi-stage configurations
• Thermowells and protection tubes, to ASME PTC 19.3 TW and DIN 43772
• Pressure relief valves, to ISO 4126, API 520/521/526, and ASME Section VIII and XIII
• Rupture discs, pipe pressure loss, heat exchangers, pipe wall thickness, and pressure surge
• From CONVAL 12 onwards: analyser probe lag time and vibration analysis to IEC/TR 61831 and ASME PTC 19.3

(F.I.R.S.T. GmbH, 2023; F.I.R.S.T. GmbH, 2024)

That breadth matters in everyday engineering. An I&C engineer sizing a control valve, checking an orifice plate, and verifying a thermowell in the same process loop would otherwise reach for three different tools, each with its own unit system and fluid property database. CONVAL consolidates them into one.

Vendor Independence in Practice

CONVAL holds a database of control valves from multiple manufacturers. Engineers can carry out an initial sizing using generic or user-defined Cv/Kv data, then cross-reference against actual manufacturer data from within the same environment. Crucially, the calculation and the manufacturer-data lookup are separate steps: the sizing result does not change depending on which manufacturer's valve the engineer selects next. That separation is the practical meaning of vendor independence, and it is exactly what a manufacturer's own tool cannot offer.

The Reliability Index

One distinguishing capability introduced in recent versions is the Reliability Index (Ri), a numerical KPI derived from an expert system built on decades of real-world valve failure data. For any given operating point, Ri gives a dimensionless rating: below 0.1 indicates no reliability problems expected; above 1.0 indicates possible mechanical damage. Where Ri is elevated, the software identifies the contributing factors, such as cavitation, flashing, choked flow, outlet velocity, steam condition and fluid proximity to vapour pressure, and provides guidance on how to address them (Vogt, 2016). For projects involving critical control valves in severe service, this moves the analysis beyond simple Cv sizing and into genuine fit-for-purpose assessment. Neither manufacturer tool in this comparison offers an equivalent.

Editions

Licences are available as single-user desktop installations or network licences, and a cloud SaaS edition is now offered, with a 14-day free trial of the cloud version (F.I.R.S.T. GmbH, 2024).

The Manufacturer Tools, and Where They Stop

Emerson's Fisher Specification Manager and SAMSON's c-SAM are both competent pieces of software. Neither is criticised here for its engineering: the calculations are sound and the IEC 60534 implementations are appropriate for professional use. The point is scope.

Fisher Specification Manager

Fisher Specification Manager is Emerson's tool for engineers specifying Fisher and Baumann control valves. Within that boundary it is well structured: it drives the ISA specification sheet from service conditions through model and trim selection, and adds noise prediction, actuator sizing, Cv-versus-travel plots, dimensional drawing reports compatible with Intergraph DDP, and project-wide tag and revision comparison (Emerson, 2012). The find-and-replace and tag-comparison functions are genuine time-savers on large Fisher instrument lists.

What it does not do is size valves from any other manufacturer, and it does not cover orifice plates, thermowells or relief valves. It is a Fisher and Baumann configurator, not an independent I&C calculation environment. On any project where the valve brand is open, or where the process points to a valve type Fisher and Baumann do not make, the tool has nothing to say.

SAMSON c-SAM

c-SAM takes the same shape: serious calculation capability anchored to SAMSON's own product range. It carries an engineer from process data through Cv/Kv, pressure drop, choked flow, cavitation, flashing and aerodynamic noise, multiple operating points, valve authority, and actuator sizing, to a complete valve-and-actuator recommendation (SAMSON AG, 2026). The methodology is sound and SAMSON's engineering heritage is substantial.

The sizing maths is vendor-neutral in principle, because IEC 60534 applies to any control valve, but the selection step routes exclusively into SAMSON's catalogue. An engineer who needs to weigh SAMSON against two other manufacturers still has to do that comparison somewhere else, on a neutral platform.

Side-by-Side Comparison

Which Tool Fits the Job

A manufacturer's own configurator is the natural choice in exactly one situation: the valve brand is already fixed to that manufacturer, and the task is to document it. An Emerson distributor quoting Fisher valves, or a site standardised on SAMSON, will reasonably reach for the matching tool to produce the specification sheet.

Every other situation calls for a vendor-neutral environment:

• You are specifying across manufacturers, or the manufacturer has not been chosen yet
• The project requires calculation traceability to named standard editions for FEED, detail engineering or regulatory submission
• You also need to size orifice plates, thermowells, relief valves or other instruments in the same project
• The service involves two-phase flow, critical flashing, severe cavitation or other complex conditions where the Reliability Index adds real insight
• You need one calculation environment across multiple discipline types on a whole project

That is the independent process and instrumentation engineer's world, and it is the world CONVAL was built for.

A Practical Note on Workflow

The tools are not always mutually exclusive. A common and sound workflow is to use CONVAL for the initial sizing and the fit-for-purpose check, establishing the technical requirement on a neutral platform, and then let each shortlisted manufacturer's tool generate its own specification sheet and dimensional data for procurement. The engineering judgement lives in the neutral calculation; the manufacturer's tool simply produces the purchase document in the format that manufacturer expects.

This is particularly valuable on competitive-tender projects. Using a manufacturer's tool to evaluate whether that manufacturer's own valve is suitable introduces a structural alignment between the calculation environment and the outcome, which many procurement organisations and end-user quality systems prefer to avoid. Vendor independence during the technical evaluation phase protects the integrity of the comparison, and that is precisely what CONVAL is for.

References

• F.I.R.S.T. GmbH (2023) Standards Used in CONVAL 12, November 2023. Available from the CONVAL 12 installation pack.
• F.I.R.S.T. GmbH (2024) CONVAL® 12 Editions and Features. Available from the CONVAL 12 installation pack.
• F.I.R.S.T. GmbH (2024) What Is CONVAL®? Available at: https://conval.de/en
• F.I.R.S.T. GmbH (2024) CONVAL Software. Available at: https://software.firstgmbh.de/en/conval
• Emerson (2012) Fisher Specification Manager: Quick Start Guide D103533X012, December 2012.
• SAMSON AG (2026) c-SAM Valve Sizing. Manufacturer product literature.
• Vogt, A. (2016) 'Applying KPIs for valve reliability in projects with valve manufacturers, EPCs and end-users', Industrial Valves 2016/2017, pp. 37-39. Available from the CONVAL pack, F.I.R.S.T. GmbH.