ANDREAS VOGT - F.I.R.S.T. SOCIETY FOR TECHNICAL AND SCIENTIFIC SOFTWARE APPLICATIONS MBH
Depending on the environment in which one operates, dealing with the topic - perhaps the sizing of a valve or the selection of a suitable actuator - is often limited to the individual component taken out of context.
For the sales engineer of a valve company, this is common practice. He limits himself only to the device to be sold, from the narrow range of products and applications available to him. Therefore, very specialised tools, often less technical than sales-oriented are often used here but they are sufficient for the purpose at first sight. As a rule, these tools are manufacturer-specific and partly work with proprietary methods, even though there may be a corresponding standard/norm for a task. Sound prediction for valves is a good example here. The range and history of standardised procedures is already large, that of proprietary, sparsely documented methods perhaps even larger. This drastically limits the validity of the predictions, especially for a product comparison.
A Valve Integration Centre has different requirements as a much broader spectrum of devices has to be considered. If you are involved in plant planning, operation or maintenance, the whole thing looks different. The spectrum of components and their manufacturers, as well as the context in which they are operated, is enormous.
The goals pursued are also different with safety, long-term reliability, energy efficiency and low maintenance etc. clearly in the foreground as often it is no longer a question of procuring new valves or actuators. Process plants and their process parameters take on a life of their own. This regularly pushes installed components to their limits or even beyond. For example, in the case of a revamp, a capacity expansion or even just a different mode of operation, due to the associated changes in the process data. The focus here is on anticipating potential problems and evaluating possible solutions.
Manufacturer-specific/proprietary tools quickly reach their limits for many reasons. Not only because they do not cover all the devices that occur, but also because they are simply not designed to predict the effects of changing process data on these components, let alone to calculate the process data correctly in the first place.
Pure valve or actuator design tools are not sufficient here. Starting with the calculation of process data such as media properties (density, viscosity, boiling pressure) up to the thermodynamic simulation or change of process data by the valve (temperature change, flashing, sound velocities), further tools must be in the toolbox here.
Figure 1 shows an overview of the most important main modules of CONVAL®, and it quickly becomes clear that this is not only about valves of all kinds, but also about the adjacent areas and components.
Figure 1
All these modules are subject to constant further development and maintenance, based on the development of standards, the latest findings from research and development or simply driven by user requirements, so that the software is updated several times a year. Proposals for standard adaptations, such as improvements to DIN/IEC 60534-2-1 for viscosity correction presented here, *1can be made available to users immediately.
In addition, new main versions are released cyclically, as was just the case with Release 11, which, in addition to extensive improvements and expansion of existing functionality, also contains completely new modules.
Standards maintenance has taken place in the safety valve module, here the calculation of two-phase flows according to the current ISO 4126-10 has been added, previously only the Omega method of API 520 was available. Another example of extensions to existing modules is the calculation of boundary hole discs. Long integrated in the control valve module for multi-stage relief on the downstream side of the valve, it now also offers multi-stage design of single or multi-hole discs in the detached variant.
A current case from practice enables a customer (a Valve Integration Center in the USA) to quickly and flexibly design multi-stage single-hole discs that are connected in front of the valve in steam applications.
Whereas in the past it took hours for an initial design, with CONVAL® the design can be done in minutes, and a recalculation with changed operating data can even be done with just a few clicks in the programme. CONVAL® already suggests sensible differential pressures during the design, determines and takes into account the necessary plate thicknesses, etc., i.e. it not only performs the calculation, but also suggests a design that has been tried and tested from experience and can then be modified. Or, as in this case, a customer's design (Figure 2), which was too loud, could be improved considerably (the overall sound level was reduced by 5dB(A)) by using the design automation in CONVAL®
(Figure 3).
Figure 2
Figure 3
New modules enable, for example, the calculation of control valves for steam coolers or the design of the drive train of automated valve assemblies with quarter-turn actuators.
The latter is based on the "Recommended Practice S2812-X-19" (hereinafter referred to as RP) published by the WIB*2 in June 2019. We have already published a basic article on this topic in Industrial Valves*3 and Industrial Fittings*4.
In addition to the technical implementation, which must be able to capture and calculate all eventualities of an application, CONVAL® focuses on the presentation and visualisation of the results. Users who do not work on valve topics on a daily basis find it difficult to interpret the results.
In order to ensure that the resulting evaluation is reproducable - regardless of the person - the software has a long history of using KPIs*5 and a traffic light system for the evaluation, as well as graphical representations to clearly illustrate the facts. In the area of control valves*6 , this has long been a standard feature of CONVAL® and has also been consistently implemented in new modules, e.g., for automated valve assemblies (Figure 2). Whereas control valves have a reliability and controllability index, here there is a suitability index (SI), which clearly indicates how well a selected actuator fits the valve application. As with the other KPIs in CONVAL®, the rule is: the closer to 0 the better.
Figure 4
In addition, a traffic light system (Figure 5) quickly indicates the suitability of the selection for the application. The graphical presentation of the underlying data complements and explains the evaluation of the traffic light system.
Figure 5
Figure 6
The examples given make it clear that CONVAL® is a solution that offers general, yet very detailed solutions for all valve applications (and more). One essential point has not yet been mentioned, but it is what makes the whole application complete, and that is the device data and properties. In our view, it is by far the most time-consuming part of software maintenance. In comparison, the implementation of the mathematics is easy.
With each new module we face the same challenges, namely to persuade and convince the manufacturers to make the data of their valves and actuators available. Whereas in the case of control valves we have succeeded step by step over the past decades in incorporating essential device data into CONVAL® in cooperation with the manufacturers and keeping it up to date, we are still at the beginning with quarter-turn valves and their actuators. But as is so often the case, the demand from our users worldwide plays its part when they approach the manufacturers and request the data in CONVAL® not only from us.
As a software manufacturer, we are not only looking to partner with end users here, but also with equipment suppliers, as we are convinced that together we can create an advantage for our mutual customers.
Well-documented exchange file formats in Excel and maintenance programmes are available for recording the data. It goes without saying that our support team assists the manufacturers with advice, practical assistance and test licences to ensure quality assurance.
*1. Vulkan Verlag - Industrial valves, Issue 4/2020 Improvements in the Kv value calculation of control valves with small valve Reynolds numbers
*2. WIB - "The International Process Automation Users' Association" www.WIB.nl
*3. Vulkan Verlag - Industrial Valves, Heft 2018/2019, "How to solve the Actuated Valve (AV) Assembly Torque Requirement Puzzle? ”
*4. Vulkan Verlag - Industriearmaturen, Issue 3/2020The treatment of "Automated Valve Assemblies" as "Engineered Products".
*5. Key Performance Indicator - Evaluation ratios for calculation results
*6. Vulkan Verlag - Industrial valves, issue 2/2012 Performance analysis of valves using a reliability index in CONVAL®
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email: sales@dp-flow.co.uk
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