Challenge

Week 14 challenge

CChandika Bhargava Varma19 May 2023

Objective

The objective of this project is to model a butterfly valve and apply GD&T to the different parts and assembly of the butterfly valve.

Introduction

A Butterfly valve is a quarter-turn rotational motion valve, that is used to stop, regulate, and start a flow. Butterfly valves are easy and fast to open. A 90° rotation of the handle provides a complete closure or opening of the valve. Large Butterfly valves are usually equipped with a so-called gearbox, where the handwheel by gears is connected to the stem. This simplifies the operation of the valve, but at the expense of speed.

Applications of Butterfly Valves

A Butterfly valve can be used in many different fluid services and they perform well in slurry applications. The following are some typical applications of Butterfly valves:

Cooling water, air, gases, fire protection, etc.
Slurry and similar services
Vacuum service
High-pressure and high-temperature water and steam services

Advantages of Butterfly Valves

Compact design requires considerably less space, compared to other valves
Light in weight
Quick operation requires less time to open or close
Available in very large sizes
Low-pressure drop and high-pressure recovery

Disadvantages of Butterfly Valves

Throttling service is limited to low differential pressure
Cavitation and choked flow are two potential concerns
Disc movement is unguided and affected by flow turbulence

Components of Butterfly Valve

1. Body

2. Shaft-Stem

3. Top Flange

4. Disc Plate

5. Lever Handle

6. Nut

1. Body

The body of the butterfly valve is the part that fits between the two pipes. This slim valve comes in two major body styles: wafer and lug. The wafer style body is the most economical of the two. It is connected to the pipes with bolt holes that run through the body of the valve.

Procedure for creating the Butterfly Valve Body:

First Create 2 circles of Dia 280. and 194 mm.

Extrude the above diagram.
Next draw the outer rings as shown below.

Now Extrude them.

Now press Ctrl+T{Move Object command} and move the outer rings as per dimensions.
Now draw the circle and Extrude it.
Then Using CounterBore option as per required dimensions create the hole in the body.
Use substract command to remove the material.
Then draw a Hole of 20.3mm and 15 mm depth.
Then use pattern command and place the holes at required positions.
Then using Extrude command and substract option create the body as required.
At Last Use UNITE Command and combine all the parts to make it as a single body.

2. Stem/Shaft

The stem of the butterfly valve may be a one-piece shaft or a two-piece (split-stem) design.

Procedure for creating the Shaft of Butterfly Valve:

First draw the sketch as shown below.

Using revolve command Extude the sketch along the base.

Draw the sketch as shown below.

Using Extrude comand and Substract option create the model as below.

Draw the sketch as shown below.

Using Extrude comand and Substract option create the model as below.

Draw the sketch as shown below.

Using Extrude comand and Substract option create the model as below.

Apply Chamfer as per dimensions.

Different views:

Diagram view:

3. Retainer

The retainer is a specially shaped washer that fits over the top of the valve spring. The keepers, or locks, fit into the valve stem grooves, holding the retainer and spring in place.

Procedure for creating the Retainer of Butterfly Valve:

First draw the sketch as shown below.

Using revolve command Extude the sketch.

Different views:

Diagram view and GD&T :

4. Disc

The flow closure member of a butterfly valve is the disk. The disk is the equivalent of a plug in a plug valve, gate in a gate valve or a ball in a ball valve. Rotating the disk one-quarter turn or 90 Degrees opens and closes the butterfly valve.

Procedure for creating the Disc plate of Butterfly Valve:

First draw the sketch as shown below.

Using Extrude command Extude the sketch as below.

Different views:

Diagram view with GD&T :

5. Lever

The hand lever is commonly used for small butterfly valves and is used to open and closed the valve. It is capable of being locked into a position of open, partially open, or closed.

Procedure for creating the Lever handle of Butterfly Valve:

First draw the sketch as shown below.

Using extrude command Extude the outer circles first as shown below.

Using extrude command Extude the middle portion as shown below.

By using the UNITE command combile all the bodies as a single Body.

Different views:

Diagram view and GD&T :

6. Nut

Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together. The two partners are kept together by a combination of their threads' friction.

Procedure for creating the Nut of Butterfly Valve:

First draw the sketch as shown below.

Using extrude command Extude the Sketch as shown below.

Draw the sketch as shown below.

Using revolve command and Substract option create the model as shown below.

Different views:

Diagram view and GD&T :

Screw:

Two screws are used for attaching shat and disc.
Three screws are used for the arrachment of retainer to the body.

Procedure for creating the Nut of Butterfly Valve:

First draw the sketch as shown below.

Using revolve command Extude the sketch along the Y-axis.

Draw the sketch as shown below.

Using Extrude comand and Substract option create the model as below.

Different views:

Assembly

After modeling all the individual parts of the butterfly valve, all parts are assembled together in the assembly workbench of NX.

First we add all the individual parts using add command.
After getting all the parts in an singular interface by using move component command we move the parts where they are requires and in necessary alignment.
Then by using Assembly constraints option we combine the parts and make it as a single asssembly.

Different views: