Characteristics of Mechanical Design in Plant Engineering

▣ Expertise and Dependence in Plant Engineering

Engineering Department for Plant Construction

Composition – Composed of specialized design groups:

• Process

• Mechanical Equipment

• Piping

• Instrumentation and Controls

• Electrical

• Civil/Architectural/Structural, etc.

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Deliverables in Each Specialty

• Often serve as foundational information for other specialties, creating interdependence among them.

• They are integrated and used for procurement or on-site construction after going through an established review process.

Coordination and cooperation are essential at the appropriate timing, with each group producing their deliverables based on shared design data.

 

 

 

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▣ Characteristics of Mechanical Design Tasks in Plant Engineering

(1) Differences between the Mechanical Equipment Design Group and Other Design Departments:

Mechanical Equipment Design GroupOther Design Departments

 

 

Features	Installation of equipment manufactured by specialized vendors	Primarily designs focused on on-site construction using bulk materials
Main Deliverables	Support documents for equipment procurement (exceptions include fields fabricated tanks)	Drawings

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(2) Differences from General Mechanical Design:

Plant Mechanical DesignTasks aimed at accurately conveying project requirements to the manufacturer, i.e., design for procurement, focusing on specifying the purpose, operating conditions, and expected functions.

 

General Mechanical Design

Design aimed at creating mechanical equipment, including the creation of procurement specifications and a series of technical activities to ensure that the manufacturer (vendor) is producing the equipment correctly.

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▣ Essential Common Skills and Knowledge for Mechanical Equipment Design

(1) Essential Common Skills and Additional Necessary Knowledge

Essential Common SkillsAdditional Necessary Knowledge

Noise & Vibration	Understanding of Codes & Standards
Stress Analysis	Understanding the nature of plant engineering work (Coordination & Cooperation)
Welding	Document writing and comprehension skills (with communication)
Metallurgy
Heat Transfer

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(2) Effective Technical Management

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(3) Bodies that Establish Various Codes and Standards

Establishing BodyExamples

 

Expert groups, such as academic societies	ASME
Public organizations, such as national bodies	ANSI, KS
Manufacturers	TEMA
Users	API

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▣ Material Requisition (MR) for Equipment Procurement

 

• The most important deliverable in plant design.

An essential tool for effectively communicating the technical requirements of the client to the vendor to perform procurement support tasks.

The procurement support activities of the mechanical design team are a measure of their design capabilities.

Must be managed and supplemented according to approved procedures.

-> Plant Mechanical Design Tasks: Writing the MR.

Standard forms are typically used but can be modified according to project characteristics.

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▣ Workflow of Mechanical Design Tasks

(1) MR Preparation

• As soon as a project starts, the mechanical design team immediately begins preparing the MR.

Based on the P&ID, Equipment Data Sheets, and Equipment List created by the Process Team, they prepare Equipment Specifications, Standard Drawings, a list of applicable Codes, a list of available Utilities, and Mechanical Data Sheets.

They group the mechanical equipment and prepare an MR List.
They recommend appropriate vendors for each type of equipment, considering the characteristics of the machinery.

 

• For stationary items, they suggest how to utilize Engineering Drawings.

• In the case of items like Field Fabricated Tanks (where deliverables include drawings and Bill of Materials), they develop a separate design work plan, such as subcontracting.

 

(2) Notifying Relevant Departments

• Simultaneously, the mechanical design engineer promptly provides the following information to relevant departments:

– Preliminary Loading Data
– Preliminary Equipment Dimensions
– Motor List & Estimated Electrical Power
– Painting B/M
– Insulation B/M, etc.

 

(3) Sending the ITB

 

• During the same period, the procurement department sends the Invitation to Bid (ITB) to the vendors (bidders) based on the MR issued by the mechanical design team and, after receiving quotes, requests the mechanical design team to review them.

 

(4) TBE / Revised MR Preparation

 

• The mechanical design team revises the Material Requisition (MR) to reflect all the technical contract conditions decided through the Technical Bid Evaluation (TBE) and issues it for [Issued for Purchase] or [Technical Purchasing Specification: TPS].

 

The issued Revised MR serves as the technical standard for design activities.
Prior confirmation is mandatory through a Kick-Off Meeting, and it must include agreements on the Vendor Print Index and Schedule.
It later becomes the official document of the Purchase Order (PO).

 

(5) Review of Vendor Prints

 

• After the PO is issued, the vendor submits the Vendor Prints as they manufacture the equipment. The mechanical design team reviews them to ensure the following points are adequately reflected:

Review Items

• Technical requirements specified in the TPS

• ITB Requirements

• Code & Standard Application

• Strength Calculation

• Site Conditions

• Welding and Metallurgy

• Noise & Vibration, Stress Analysis

• Information needed from related design disciplines

• Design Interface Information: Nozzle Orientation, Termination Point, Electrical & Control, Shipping Condition

• Information related to construction: Nozzle Opening for stationary items, Inspection-related matters, Spare Parts List, Lubricant Information, Utility Information, Mechanical Data Book, including Operation and Maintenance Manual.