allow assignment of pressure drop in control valve, to allow pump sizing by design
Raymund Gimenez
I have ran a pump system, where pump and valve are selected as "design". I understand that this is also not possible in the local version of fluid flow. Its either the pump curve is specified, or the control valve curve is specified (i.e. created in database both instances). Normally in pump hydraulics in excel spread sheet, we usually assign 70 kPa as minimum pressure drop of a valve, to estimate the pump head (or size the pump).
I have saved in cloud,file name "2024-1115-0001_.fd"
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Michael Ross
Hi Raymund,
Thanks for the feedback. FD is designed to cater for this type of design situation and we should have some videos available explaining how to do this before release. In the meantime please find attached a version of your original file that I have adjusted in order to acheive the solution you require. You will need to change the file extension from .json to .fd so you can load locally. As a brief explanation I have made the following changes. 1. Increased the backpressure in the recycle line by adding a 20mm orifice (or we could use a pressure sustainer). and 2. Changed the Case Mode of the control valve from Design to Rating. Then within Rating I changed the Operating Mode to operate with your desired pressure loss of 70 kPa.
The system now calculates. In this type of system design the approach would typically be in the following steps 1. Size the pipes with the pump set in design mode for flow. At this stage, control valves should be set to Rating mode with either a desired Kv or a desired pressure loss. 2. Use smart select to make a pump selection and insert the selected pump. 3. Change the control valve to design mode at the desired flow and then use smart select to select the control valve. All will be clearer hopefully with the publication of our system design videos.
Apologies that they are not ready at this time.
Michael Ross
