Week 14 challenge

BUTTERFLY VALVE ASSEMBLY

AIM:

• To assemble and apply GD&T to the butterfly valve assembly drawing.

INTRODUCTION:

• A Butterfly valve is from a family of valves called quarter-turn valves. 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 shaft. When the valves is closed, the disc is turned so that it completely blocks off the passageway. When valve is fully open, the disc is rotated to quarter turn so that it allows an almost un restricted passage of the fluid.The valve may also be opened incrementally to throttle flow. There are different kinds of butterfly valves, each adopted for different pressures and different usage.
• Here, after modelling various components of the butterfly valve, GD&T is applied to each component and final assembly. GD&T is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer generated 3-D solid models that explicitly describe nominal geometry and its allowable varitaion. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part. GD&t is used to define the nominal geometry of parts and assemblies, to define the allowable varition in form and possible size of individual features, and to define the allowable variation between features.
• There are several standards available worldwide that describe the symbols and define the rules used in GD&T. One such standard is American society of mechanical engineers (ASME) Y14.5. This article based on that standard, but other standards, such as those from the International Organization for Standardization (ISO), may vary sligthly. The Y14.5 standard has an advantage of providing a fairly complete set of standards for GD&T in one document. The ISO standards, in comparison, typically only address a single topic at a time.

ADVATAGES OF APPLYING GD&T:

Cost Efficient:

• It enhances design accuracy by allowing for appropriate tolerances that maximize production. For many projects, the process provides extra or bonus tolerances, further increasing cost effectiveness.

Offering Uniformity and Conveniece:

• As a single, consistent language, GD&T reduces guess work and interpretation while ensuring consistent geomertries across design and manufacturing.

Assisting Digital Design Methods:

• Clear, concise GD&T data is readily adoptable to design programme, including nearly universally used 2-D and 3-D CAD files.

Insuring Dimensional and Tolerance Requirements:

• By explicitly stating all design requirements, through GD&T process gurantee accurate fulfillment of all dimensional and tolerance specifications.

Providing Accurate Communication:

• Today's intricate designs demands the most accurate and reliable communication. GD&T enables designers, manufactures and inspectors to communicate clearly with one another, saving time and making the process more efficiently.

BUTTERFLY VALVE COMPONENTS:

Various component of butterfly valve and GD&T applied to them are shown below:

1. BODY OF BUTTERFLY VALVE:

• Butterfly valves are usually fixed between two pipelines using flange couplings. Body of our Butterfly valve and GD&T appiled to the same using Siemens NX CAD as shown below:

2. SHAFT- BUTTERFLY VALVE:

• The Disc/ Plate, Lever and nut are assembled to this shaft.

3. DISC- BUTTERFLY VALVE:

• When valve is fully opened or closed the disc is rotated a quarter turn. Disc is mounted on shaft. 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.

4. LEVER- BUTTERFLY VALVE:

• Lever is mounted at an end of shaft outside the body. Hand lever is usually used in small sized Butterfly valves. It is used to open or closed the valve.

5. RETAINER:

• Retainer is a kind of washer fixed on the body of butterfly valve.

6. NUT- BUTTERFLY VALVE:

• It is fixed at the top end of shaft to keep the lever and retainer on position relative to the body of butterfly valve.

ASSEMBLY- BUTTERFLY VALVE:

• After completing the modelling of various components of butterfly valve, all parts were assembled together using Siemens NX Assembly workbench.

CONCLUSION:

Butterfly valve was successfully designed and GD&T applied to all parts and the assembly of the butterfly valve.