The parametric analysis of Gate valve by using Ansys Fluent

Aim: The parametric analysis of Gate valve by using Ansys Fluent.

Introduction: The gate valve is a device that is used to control the fluid flow in a path.

Gate valves are designed for fully open or fully closed service. They are installed in pipelines as isolating valves, and should not be used as control or regulating valves. Operation of a gate valve is performed doing an either clockwise to close (CTC) or clockwise to open (CTO) rotating motion of the stem. When operating the valve stem, the gate moves up- or downwards on the threaded part of the stem.

Gate valves are often used when minimum pressure loss and a free bore is needed. When fully open, a typical gate valve has no obstruction in the flow path resulting in a very low pressure loss, and this design makes it possible to use a pipe-cleaning pig. A gate valve is a multiturn valve meaning that the operation of the valve is done by means of a threaded stem. As the valve has to turn multiple times to go from open to closed position, the slow operation also prevents water hammer effects.

The geometry of gate valve is shown in figure 1 below.

Figure 1: Geometry of Gate valve

Figure 2: Fluid volume

• The parametric study in gate valve is analysed for different 5 design points. Initially we lift the gate disc at 5mm in upward direction and continuously lift 5mm in each parametric study i.e. 5mm, 10mm, 15mm, 20mm, 25mmetc.
• STEP 1:

• Details of Mesh:

Lift in gate valve (mm)	Nodes	Elements
5	30386	142750
10	30295	142573
15	30165	142146
20	30081	142004
25	29936	141402

• Step 2: Setup

1. Setting up physics

Solver –Steady state and pressure based used.

Model--- in this study we used viscous K-ε with Realizable and scalable wall function turbulent model for set up.

Material properties---Water: Density=998.2 kg/m³ and Dynamic viscosity= 0.001003 kg-m/s.

Boundary condition---At inlet – pressure inlet = 10 Pa, outlet = 1 atm pressure

Gravity = -9.81m/s^2 in Z-direction

1. Setting up solution

Standard initialization in this study for steady state simulation

Results:

• Case 1:

• Animation:

• Case 2:

• Animation:

• Case 3:

• Animation:

• Case 4:

• Animation:

• Case 5:

• Animation:

• Mass flow rate at outlet:

Design points	Lift in gate valve (mm)	Mass flow rate at outlet (Kg/s)
0	5	0.12282
1	10	0.14815
2	15	0.18736
3	20	0.23737
4	25	0.29422

• Conclusions:

From above tables we can say that if we increase the lift of disc in gate valve, the mass flow rate at outlet is increasing.