Week 14 challenge

Design and Assembly of Butterfly Valve by applying GD&T using NX-Cad

Objective

The objective of this project is to model a butterfly valve and apply GD&T to the different parts then assemble all parts together by applying required constraints.

Introduction

A butterfly valve is a quarter-turn rotational motion valve. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.

Applications of Butterfly valves

Butterfly valves can be used in many different fluid services and they perform well in large volume water applications and 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
• Compressed Air or Gas Applications

Advantages of Butterfly Valves

• Available in very large sizes.
• Light in weight.
• Quick operation requires less time to open or close.
• Low pressure drops and high-pressure recovery.

Disadvantages of Butterfly Valves

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

Components of Butterfly Valve

1.Body

Butterfly valves generally have bodies that fit between two pipe flanges. The most body designs are lug and wafer.

Drafting

2.Stem

In butterfly valve it may be a one-piece shaft or a two-piece (split-stem) design.

Drafting

3.Retainer

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

Drafting

4.Disc

It is a flow closure member of a butterfly valve in this assembly. The disk is 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 on 90 Degrees opens and closes the butterfly valve.

Drafting

5.Lever

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

Drafting

6.Nut

Nuts are always used mostly in conjunction with a mating bolt to fasten multiple parts together. The two parts are assembled together by a combination of their thread’s friction.

Drafting

Final Assembly

After designing of individual parts then all parts are assembled together by applying required constraints using assembly in workbench of NX.

Drafting

Conclusion

Thus, the Butterfly valve is created successfully and applied GD&T to all the different parts further by creating drafting file to individual component and assembly.