Rod Dry Dec 2013

Training Module #4: Problem Statement Water at a (constant) feed pressure of 4 barg flows through a DN400 pipe fitted with an equal percentage globe valve. Downstream there is a restriction of 200 mm ID and beyond this the sink pressure is 2 barg. The sink is elevated about 6m above the source. 1.What is the maximum water flow through this system when the valve is 100% open? 2.Will the valve provide reasonable flow control? 3.If the globe valve is replaced by a (possibly cheaper) butterfly valve, will flow control be reasonable? Water Flow Through a Control Valve

Training Module #4: Step 1 of 11 1.Click on the Quick Start Icon ( ) and say “Yes” to the current project overwrite warning. 2.Select “Pipe with Globe Valve and Downstream Orifice”, select parameters as indicated and press “Go”. 4 barg source 2 barg sink valve 100% open orifice 200 mm DN400 Sch 40 Water/Steam

Training Module #4: Step 2 of 11 1.Right-click in the fluid sink, select “Edit” and re-name it to “2 barg Sink” then click “Modify Current Fluid Sink”. (We want it re-named so we can use it later.) 2.Click on “Edit Existing Line” to open the Line Editor. 3.Press “Remove Last Section” to remove the sink.

Training Module #4: Step 3 of 11 1.Click “Edit” on Bend 1, check DN400 Pipe Sch 40 is selected and click “Accept”

Training Module #4: Step 4 of 11 1.Press “Turn Up” 2.Press “Add Pipe 1” 3.Press “Turn North” 4.Press “Add Pipe 1” 5.Select the sink (“2 barg Sink”) then press “Add Sink” If you are working with a single screen, you can click “Toggle Opacity” to make the line builder semi-transparent. You will then be able to see through it and view the pipeline as it grows…

Training Module #4: Step 5 of 11 1.Right-click on the vertical pipe section and select “Edit” 2.Set the length to 6 m and press “OK” 3.Click the “Solve” arrow

Training Module #4: Step 6 of 11 1.Select “Pressure” Maximum flow rate (valve 100% open) is 1121 t/h

Training Module #4: Step 7 of 11 1.Right-click on the valve and select “Valve Curve” 2.Select “10 Steps Across the Range” and press “Calculate” (be patient – it may take a while)

Training Module #4: Step 8 of 11 Installed valve characteristic looks OK for flow control…

Training Module #4: Step 9 of 11 1.Right-click on the valve, select “Edit” then press “Edit Valve Type” 2.Select “Butterfly Valve” then press OK. Of course, you can edit the valve curve if you wish…

Training Module #4: Step 10 of 11 1.Right-click on the valve and select “Valve Curve” 2.Select “10 Steps Across the Range” and press “Calculate”

Training Module #4: Step 11 of 11 Installed valve characteristic is not really suitable for flow control… (control action is essentially in the bottom 30% of stem position range)

Training Module #4: Solution Review Water at a (constant) feed pressure of 4 barg flows through a DN400 pipe fitted with an equal percentage globe valve. Downstream there is a restriction of 200 mm ID and beyond this the sink pressure is 2 barg. The sink is elevated 6m above the source. 1.What is the maximum water flow through this system when the valve is 100% open? Answer: 1121 t/h 2.Will the valve provide reasonable flow control? Answer: Yes 3.If the globe valve is replaced by a butterfly valve, will flow control be reasonable? Answer: No, not really… Water Flow Through a Control Valve

Final Step: Save For Future Reference 1.Select File  Save ΣPipe Project As… and call this case “Water Control Valve Example”, then press “Save”. 2.Select File  Open ΣPipe Project and verify that the case is there, ready to be opened when you need it again. Well done, we are now ready to move on to Module #5