This chapter focuses on producing assembly drawings essential for refrigeration and air conditioning professionals in Kenya. Assembly drawings visually represent how individual components fit together to form a complete unit or system, facilitating maintenance, repair, and fabrication. Mastery of these drawings ensures clear communication among engineers, technicians, and manufacturers, enhancing project efficiency and reducing errors. In particular, exploded orthographic drawings play a vital role in illustrating component relationships within complex refrigeration and air conditioning assemblies.

5.1 Exploding Orthographic Drawings

Exploded orthographic drawings are critical for refrigeration and air conditioning professionals as they provide a detailed view of how components assemble without physical disassembly. In Kenya, where refrigeration systems in hospitals, hotels, and industrial plants require precise maintenance, these drawings aid technicians in understanding complex assemblies. This topic covers the principles, construction procedures, standards, and interpretation of exploded orthographic drawings tailored to refrigeration and air conditioning systems.

5.1.1 Concept and Purpose of Exploded Orthographic Drawings

Exploded orthographic drawings visually separate components of an assembly along parallel axes while maintaining their relative positions and orientations. This presentation style reveals the order and relationship of parts, which is indispensable when dealing with refrigeration compressors, condensers, or air handling units.

• Visual Clarity: By spacing components apart, technicians can easily identify individual parts and their connections without confusion.
• Assembly Guidance: Shows stepwise assembly or disassembly sequences critical for repairing refrigeration compressors or HVAC units.
• Parts Identification: Facilitates quick identification of components, crucial when ordering replacements or checking inventory in SACCO-managed service workshops.
• Error Reduction: Helps avoid assembly mistakes by clearly illustrating how parts fit together, reducing costly downtime in commercial refrigeration systems.
• Communication Tool: Enhances understanding between design engineers and field technicians, ensuring accurate implementation of designs in factories or county government facilities.

5.1.2 Construction Procedure for Exploded Orthographic Drawings

Creating an exploded orthographic drawing for refrigeration and air conditioning assemblies requires a systematic approach to ensure accuracy and clarity.

1. Obtain the Complete Assembly Drawing: Start with a finalized orthographic assembly drawing showing all components in their assembled positions.
2. Identify Individual Components: List all parts including compressors, expansion valves, evaporator coils, and fan assemblies.
3. Determine Explosion Direction: Decide the axis along which components will be spaced apart, usually perpendicular to the assembly plane for clarity.
4. Space Components Evenly: Move parts along the chosen axis, maintaining their relative orientation and alignment to avoid distortion.
5. Connect Components with Leader Lines: Use dashed lines or arrows to link exploded parts to their original positions, aiding spatial understanding.
6. Label Each Component Clearly: Assign reference numbers or part names adjacent to each item, matching them with a parts list or bill of materials.

5.1.3 Standards and Conventions in Exploded Orthographic Drawings

Adhering to recognized standards ensures that exploded orthographic drawings are universally understood, especially in regulated environments such as hospitals or manufacturing plants in Kenya.

• Line Types: Use solid thick lines for visible edges, dashed lines for hidden edges, and thin dashed lines for explosion lines to maintain clarity.
• Scale: Maintain a consistent scale, commonly 1:2 or 1:5, to balance detail visibility and overall drawing size.
• Title Block Information: Include project name, drawing number-scale, date, drafter’s name, and revision history as per ISO 7200 standards.
• Dimensioning: Avoid excessive dimensions on exploded views; instead, provide key dimensions on the assembled orthographic drawing.
• Symbols and Notations: Use standard symbols for refrigeration components such as compressors, valves, and coils following Kenya Bureau of Standards (KEBS) guidelines.

5.1.4 Interpretation and Application of Exploded Orthographic Drawings

Understanding exploded orthographic drawings enables refrigeration technicians and engineers to perform installation, troubleshooting, and maintenance effectively.

• Component Location: Identify exact positions of parts within complex systems like multi-split air conditioning units.
• Assembly Sequence: Follow logical steps for assembling or disassembling refrigeration compressors, minimizing risk of damage.
• Maintenance Planning: Use drawings to plan part replacements or upgrades in commercial cold storage units.
• Training Tool: Serve as educational aids for new technicians in training programs at technical colleges or SACCO workshops.
• Inventory Control: Match exploded parts with inventory lists to ensure availability of spare parts during service calls.

Chapter Summary

This chapter focused on the process of producing assembly drawings using computer aided design techniques. It began by explaining how to create exploding orthographic drawings, which separate components clearly while maintaining their spatial relationships. The chapter then covered exploding pictorial drawings, emphasizing the visual clarity of parts in a three-dimensional context. Next, it detailed how to assemble different views effectively to present a complete and accurate representation of the product. The production of sectional views was also examined, showing how to reveal internal features by cutting through the assembly. Finally, the chapter discussed the development of parts lists, highlighting the importance of accurate documentation for assembly and manufacturing processes. Together, these topics provide a comprehensive guide to creating detailed and precise assembly drawings.