Commonly asked questions

If you do not find your question here please email us at

o In the event you get stuck during a tutorial step, please ensure your browser zoom is set to 100%. You can then refresh the page ( On windows hit F5 or the CTRL+R key combination ) and restart your tutorial. If you have completed all your tutorials and would like a refresher, please select the menu bar and then select the tutorial button within the menu.

o Based on the typical scope of this calculation pertaining to petroleum fluids, it has been found the viscosity does not have an appreciable impact on sizing calculation results. In the interest of simplicity, it has been eliminated from this page.

o The units most common to the industry were included on this site at launch. If you have a unit you use regularly that you would prefer to see on the site, please submit a request through our contact means and its inclusion will be reviewed.

o This portion of the site has been designed to align the most commonly available trim options for each valve size. If you are attempting to choose a valve size and trim combination that is not included in the current list, the system will attempt to reset to the next closest available product. It is possible the requested combination can be supplied as a custom product. Please contact Master Flo to discuss.

o If you have not chosen to save this valve calculation, you can revert to your earlier version by selecting a different valve from your projects list and choosing to “Continue” without saving. After this is done, reopening the original valve calculation will load the data that was stored at the previous save point.

o Your session may have expired, please save your work, log out and log back in again.

How to request a new account, activate an account and recover a lost passsword or delete your account.

Added: 2020/11/03

Valve Sizing

How to size a valve on a Cv, Pres Drop or FL Rate calculation, how to override the suggest size and trim.

Added: 2020/11/03

Actuator Sizing

How to size an actuator, commonly used actuator settings for pneumatic and hydraulic configurations.

Added: 2020/11/03

Valve Sharing

How to share a valve, how to accept shared valve items, how to save a shared valve into your profile.

Added: 2020/11/03

Learning Path - Fundamentals

Getting Started

Welcome to SizeFlo, the purpose of this website is to help you select the right choke within our wide range of products to suit your projects needs. In order to begin you will first have to create an account. You can do this be accessing the home page and selecting the create account link below the login box. Be sure to check your spam inbox as the confirmation email you recieve may end up there. You will be provided with an email activation link that will require you to press the 'Verify' button in order to complete the account request process.

After this it may take a few days for a SizeFlo administrator to determine if you are eligible for an account approval, if you are you will recieve an email saying your account has been activated and SizeFlo is now ready for use.

Folder, Subfolder, Projects and Valves

After you have logged in a tutorial window will appear prompting you to being sizing your first valve, we reccommend that you follow the tutorial to get a basic handle on how to use the various features of the website, the tutorial will cover creating a valve, calculating a choke application, viewing the Cv graphs, changing the choke sizes as well as Printing a PDF report. More tutorials to help new users famliarize themselves with the features of the website will continued to be added in future releases.

The basic structure of the website follows a specific heirarchy. Starting at the bottom and working our way up in organizational encapsulation we have:

  1. Cases: These exists within valves and contain the pressure and fluid characteristics for a choke application. You can have an unlimited amount of cases within your valve, please be adivsed it becomes less responsive the more cases that you have in a valve. You can add, copy and delete cases.
  2. Valves: Cases reside within valves, there is no limit to the amount of cases you can have within a valve, a valve can be shared with other users on the webiste if you have the email address they use to login to the website. When you accept shared valves they will appear in your Root level valve area prefixed with a '(Shared)' demarcation.

    Shared valves will not be editable by you, you can copy them into any of your projects and edit your local copy. All shared valves can be deleted from your profile, please note this will not delete it from the original user. You can add valves to:
    • Projects
    • Root level valves area

    All valves have a root level home, you can copy valves to create duplicates here, copies will be added with a '_COPY' appended to their name. You can copy valves from your root level valve area to any project you have access to excluding shared projects.
  3. Projects: Valves can either exist in the root level valves area or within projects, you can have unlimited valves within projects and your project acts like a directory for your valves. The project organizational item can be deleted which will delete all the valves within them. Projects can be edited or copied to:
    • Projects root area
    • Subfolders
    • Folders

    Projects can also be shared, which will share all the items within the project, shared projects along with their valves will be demarced by a '(Shared)' prefix.
  4. Folders: Projects can exist within the projects root area or within folders, or sub folders. Folders are the highest level of organizational encapsulation and can contain unlimited projects, or sub folders, folders can be deleted, edited or copied to:
    • Root level folders area

    Folders can also be shared, sharing a folder will shared all the contents within the folder and prefix them with a '(Shared)' demarcation, like all other shared items, they can not be edited - they can be deleted, but this will not delete the original sharers item.
  5. Sub Folders: Projects can exits within sub folders, which are another tier of organizational encapsulation. They act exactly like folders however Subfolders can only exist within folders and may only be copied to other , or the root level folders area, when copied to the root level folders area the sub folder is promoted to a folder. They can be edited, deleted and shared just like all the above items.

Valve Sizing

When sizing a valve you will need to make sure of certain conditions:

  1. The upstream pressures are greater than the downstream pressures.
  2. The flow conditions are greater than 0.

The program will then calculate the Cv based on the flow and fluid properties and size a choke for your application that it deems is most appropriate. You can change the choke size to a higher level or alter the trim used which will recalculate the flow equation outputs using the dropdowns under each case for the calculated results. You can also choose to override all the chokes or trims by using the left-most dropdown in the calculation results pane. You can view the datasheets of the chokes available for your application but selecting the datasheets button on the bottom of the calculation results pane. You can also view warnings, and display the Cv curve by selecting the graph function.

Printing a PDF

In the calculation results pane, at the bottom right you can select the Print button to bring up the print results pane. Here you can choose which cases you which to print, or select all. Additionally the Actuator Sizing calculation pane also offers the option to print your results.