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Valve sizing programs 6

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cliff6361

Materials
May 5, 2005
27
Does anyone know of a good low cost control valve sizing program available? If so please provide details. If not, know of any good engr/programer who understands control valves, fluid flow, sizing and can write programs? If so let me know.

Thanks for the help!
 
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Can you give more info, what kind of valves? Exampes?
 
Both Fisher and Valtec has good software that should be avaiable for free from the vendor.

Best regards

Mprten
 
cliff6361,
as far as I know, Manufacturers distribute their own programs following different policies (among Sales Offices only with limited versions for Customers or free download from the web, for instance...).
In addition to the ones mentioned by MortenA, I heard about Metso-Neles and Tyco-Vanessa.

Hope this helps, 'NGL
 
Flowserve (Valtek, Kammer, NAF, Schmidt, Worcester, etc.) sizing software is available for download at You can downmload a free 60-day trial. When you decide it's really neat and want to keep it forever there is a $75 one-time only licensing charge collected for a sofware company that owns some of the code. Otherwise you just get to reset the date on your computer to make it work.
 
Jim

If you actually purchase valves on occation you dont have to pressure your valve vendor a lot in ordre to get a "free" copy.

Best regards

Morten
 
Most free or very low cost sizing and selection software given away by a vendor is generic by nature and won't contain all the selections that their in-house propriatary sizing software will give them.

First, they can't trust that untrained persons will fill in all the really technical but necessary parameters needed to make a proper selection, and:

Second, they don't know where those programs will end up, and they certainly don't want their propriatary designs to end up on the desk (computer) of their competitor.

You are probably not going to get much more than you could calculate by using standard engineering references like Perry's, Marks, Crane, Cameron Hydraulic, et. al. but at least the software will take the tedium out of the process, and allow you to use modern tools.

So, use anything you get with that in mind. Still, most of them will allow you to do some decent process evaluations, etc., and run it over and over until you get it close.

rmw
 
rmw

I agree - and in the end it will be the vendor who offers a valve that he feel suits your spec. Some of us, however, likes to look over his shoulder a little. And even though we dont live from selleing valves - we may be slightly more informed that "untrained" :)

Best regards

Morten
 
Hi cliff6361,

I am not quite sure how you are going to use "this control valve sizing program", or if I understand quite what you mean by "valve sizing program". However, here are some thoughts:

Each valve that you chose will have a Cv number that you need to get from the manufacture. Fisher, for example, in their FirstVue sizeing program includes this, and you are then able to match your Cv requirement to the valve's Cv. I would think that other vendors's sizing program does the same. This would mean that if you plan to buy a Fisher valve, you most likely would want to use their sizing program, and the same for each other valve manufacturer.

On the other hand, if you mean a "valve sizing program" to determine what the required Cv of the valve would need to be, then that is a different type of program. That is almost into the realm of a process simulator/modelling progarm. In this case, you are looking at flowrates, upstream/downstream pressures, including pumping curves etc. to determine the max/norm/min flow conditions to determine the range of Cv for the valve. If this is the case, there are vendors such as Aspen/Hyprotech that sell packages that may meet your needs.

Hope this helps.
 
In order to specify a control valve a program such as AFTs Fathom can be used. Especially if you use their goal seeking and extended time simulation modules. Then you will be able to specify to the control valve vendor what the process conditions are to be met. The best use of vendors software is to check the salesmens figures. Some are better than others.

In my experience it has been preferable to establish a relationship with a control valve company so that you can trust them. Even then check their interpretation of your figures. They can make mistakes as well. If you have a relationship then even their mistakes can be forgiven.

You cant expect the control valve company to be responsible for your process nor they expect you to be responsible for their product. Its the grey area in between that both parties need to be adequately informed. Dot be tempted to save a few bob and leave all to the salesmen.

 
The Fisher valve handbook has got their valve sizing equations in it and I just made up a spreadsheet for myself to use including the effect of cavitation on valve sizing.

It's not nearly as powerful as the vendor's program of course but it's more than adequate when I want to estimate the Cv required and what size valve I'm likely talking about. It was enough to caught a mistake when our instrument engineer was sizing a control valve based on my min/normal/max conditions and I did a quick check of the Cvs and they weren't even close. Turned out somehow he had mixed up the outlet pressure for the cases and used them in one calculation while showing them in the 'correct' column(s) on the data sheet. I'm not quite sure how he did that but he didn't believe me until I got him to use his program and the conditions for a given case and lo, the calculated Cv didn't match the data sheet's condition but matched my spreadsheet value.
 
One common mistake made in sizing control valves is the use of units. Many programs require inlet and outlet pressures to be input in absolute pressure units.

For cavitation prediction I found the Valtek (Flowserve) sizing program to be very good.

 
Many years ago EPRI did a study on why large diameter butterfly valves were cavitating in large supercritical power plant even though the equations indicated they shouldn't be cavitating. They found that the equation was based on the flow to square root of delta P curve of a globe valve. Choked flow occured at 2% above the point of incipient cavitation.

Hydrodynamic noise testing found that ball and butterfly valves would exhibit incipient cavitation way before choked flow occured.

Metso Automation's "Nelprof" sizing program calculates the "Terminal Pressure Drop" per the equation but in addition provdes the noise calculations with limits to indicate when the valve may in fact be in moderate cavitaion.

Futhermore I believe it to be the only program around that given accurate process data will provide both the "inherent" and "installed" characteristic. This is very helpful in optimizing loop tuning.

It is frustrating to learn and use some days but has been extremely reliable in my work through the years.
 
Fisher FirstVue is a good. Similarly, Performance 9.? (I forget the latest revision) is very good. Be careful utilizing noise figures predicted by the sizing programs. Many utilize "in house" formulas/factors/voodoo to generate noise figures. The last program I wrote utilizes the ISA algorithm and is consistent with the IEC guidelines (unless I've really missed something) for aerodynamic noise prediction. Unfortunately, ours is written around our products; and is only setup to handle HC liquid/water/HC gas so I doubt it would be of help to you.

don f.
 
Hi,

Some of the valve manufacturers have sizing programmes available on their website. Bray butterfly valves have one.

If you do not have any luck please contact me, and I can put you in touch with a valve engineer who may be able to help you with a customised programme
 
I'am looking for Air Admission Valves Vent-O-Mat. Is there a representative in Europ?
Is there any whone who knows who to model these valve in Flowmaster?
 
Ventomat air valves will be modelled in AFTs Impulse versin 4 to be released early next year. They can be modelled in Surge 2000, Hytran and Watham as we speak. I think DFLowmaster are behind the pack.

That said if it air admission you seek to model then the full valve size can be modelled as the orifice size. Ventomat air valves restrict only the air discharge by use of multiple orifices.

Air admission at maximum can only have the differential pressure between atmospheric and full vacuum. The program should determine if the air velocity is critical or not and apply the correct formula.

 
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