FIRE: Introduction

ALL ABOUT FIRE 

Fire is the most common serious hazard that one faces in an industry or residential complex. While proper procedure and training can minimize the chances of an accidental fire, you must still be prepared to deal with it.

Fire Triangle is a tetrahedron, because there are four elements that must be present for a fire to exist. There must be oxygen to sustain combustion, heat to raise the material to its ignition temperature, fuel to support the combustion and a chemical reaction between the other three elements.

Remove any one of the four elements to extinguish the fire.

The concept of Fire Protection is based upon keeping these four elements separate.

Types of Fires:

Not all fires are the same. Different fuels create different fires and require different types of fire extinguishing agents.

Class A : Class A fires are fires in ordinary combustibles such as wood, paper, cloth, trash, and plastics. In simple terms, we can define Class A fire as the fire which occurs in SOLIDS. 

Class B: Class B fires are fires in flammable liquids such as gasoline, petroleum oil and paint. Class B fires do not include fires involving cooking oils and grease.  In simple terms, we can define Class B fire as the fire which occurs in LIQUIDS.

Class C: Class C fires are fires involving flammable gases such as propane and butane. Energized electrical equipment such as motors, transformers, and appliances also covers under this class.

Class D: Class D fires are fires in combustible metals such as potassium, sodium, aluminum, and magnesium.

Class K: Class K fires are fires in cooking oils and greases such as animals fats and vegetable fats.

TMT Bars for Constructions

TMT Bars

TMT stands for Thermo Mechanically Treated. The TMT bars have a hard outer surface and a softer core. Their manufacturing process includes hot rolled steel wires passed through water. This makes the surface hard and keeps the core warmer and softer. This helps in making the steel corrosion resistant and also increases its weldability.

On the other hand, HYSD stands for High Yielding Strength Deformed bars. These bars have more yield strength than Mild Steel. Unlike TMT bars, HYSD bars are both hot and cold worked. They are graded as Fe 415 or Fe500.

The Indian Specification for High Strength Deformed Steel Bars and Wires for Concrete Reinforcement (IS1786) has indicated three strength grades Fe 415, Fe 500 & Fe 550 which is given below in table. The numbers after the prefix Fe indicate the specified minimum yield strengths in MPa unit.

Mechanical Properties:

SL No.	PROPERTY	GRADE
		Fe 415	Fe 500	Fe 550
i)	0.2 percent  proof stress/ yield stress, Min, MPa	415.0	500.0	550.0
ii)	Elongation, percent, Min, on gauge length 5.65 ÖA, where A is the cross-sectional area of the test piece.	14.5	12.0	8.0
iii)	Tensile strength, Min	10% more than the actual 0.2% proof stress but not below 485.0 MPa.	8% more than the actual 0.2% proof stress but not below 545.0 Mpa.	6% more than the actual 0.2% proof stress but not less than 585. MPa.

Carbon Content and Carbon Equivalent: The Indian Specification (IS 1786) limits the carbon content to 0.25% maximum and carbon equivalent to 0.42% maximum (0.53% for low alloy steel) for guaranteed weldability. Steel manufacturer in India maintains a carbon equivalent of 0.18% with a standard deviation of 0.03% across all sections including those rolled in a high-speed wire rod mill.

Sulphur and Phosphorus Content: The Indian Specification (IS 1786) calls for sulphur and phosphorus content of 0.060% Max. Steel manufacturer in India maintains at levels considerably below the specification.

Percentage Elongation: The Indian Specification (IS 1786) stipulates 14.5% elongation minimum. However, in India most of the integrated steel plant maintains the elongation values between 22 to 25%.

UTS / YS Ratio: In the case of UTS/YS ratio Indian Specification (IS 1786) stipulates an UTS / YS ratio of 1.10, 1.08 and 1.06 for the Fe415, Fe500, Fe550 grades respectively. But all the steel manufacture in India maintains this value more than 1.15 in India.

Chemical Composition of Steel for TMT and other grades:

Typical chemical compositions of steel for TMT adopted by a reputed steel manufacturers for different sizes are given below:

S.N	TMT size in mm	Carbon percentage	Manganese percentage
1	8-12	0.19 to 0.23	0.54 to 0.84
2	16	0.11 to 0.15	0.50 to 0.66
3	20	0.09 to 0.17	0.50 to 0.66
4	25	0.17 to 0.25	0.51 to 0.75
5	28	- do-	0.99 to 1.11
6	More than 28	- do-	0.89 to 1.01

  

IES 2017 Syllabus for Mechanical Engineering

The As per the official declaration and notice from UPSC, IES ESE (Engineering Services Examination) 2017 syllabus has been changes and provision of Preliminary examination followed by Mains examination has been introduced.

Changes:

In Stage I there will be two papers:

1. General Studies and Engineering Aptitude Paper (2 hours) - 200 Marks
2. Engineering Discipline Specific Paper (3 hours) - 300 Marks.

Total Marks: 500

Stage-I is mandatory for all applicants and is to be qualified for entry to Stage-II.

Stage-1: Paper-I is General Studies and Engineering Aptitude having 10 sub sections namely:

1.    Current issues of national and international importance relating to social, economic and industrial development.

2.    Engineering Aptitude covering Logical reasoning and Analytical ability.

3.    Engineering Mathematics and Numerical Analysis.

4.    General Principles of Design, Drawing, Importance of Safety.

5.    Standards and Quality practices in production, construction, maintenance and services.

6.    Basics of Energy and Environment: Conservation, environmental pollution and degradation, Climate Change, Environmental impact assessment.

7.    Basics of Project Management.

8.    Basics of Material Science and Engineering.

9.    Information and Communication Technologies (ICT) based tools and their applications in Engineering.

10. Ethics and values in engineering profession.

In Stage II there will be two papers:

1. Engineering Discipline Specific Paper I (3 hours) - 300 Marks.
2. Engineering Discipline Specific Paper II (3 hours) - 300 Marks.

Total Marks: 600

In Stage III there will be one personality test:

• Personality Test - 200 marks

Total Marks: 200
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Grand Total: 500 + 600 + 200 = 1300 Marks.
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Only those candidates who will qualify Stage -I will be permitted to appear in Stage-II examination. Similarly, only those Candidates qualifying at Stage-I + Stage-II will be permitted to appear in Stage-III examination.

BRIEF REPORT OF THE CHANGES

·       Approximate number of candidates qualifying for stage II is likely to 15 times the number of vacancies in each discipline.

·         Syllabus of technical subjects for preliminary as well as mains is identical.

·         GATE syllabus is a subset of ESE-2017 syllabus.

·    Weightage of stage-2 or conventional papers is up from nearly 33% till ESE 2016 to about 46% from ESE 2017 onwards.

·         Total score of all the 3 stages from ESE- 2017 onwards is up from 1200 to 1300.

·    Paper-I worth 200 marks and of 2 hours duration with equal weightage for General English and General Studies till ESE 2016 has been replaced with General Studies and Engineering Aptitude having 200 marks and 2 hours duration having 10 sub sections (detailed earlier).

·     Special emphasis on a number of subjects which are part of common B. Tech. course curriculum in nearly all institutions/universities.

·     In Mechanical Engineering stream, 2 new subjects have been added namely: Renewable Sources of Energy and Mechatronics and Robotics.

Old IES Syllabus-Mechanical Engineering

Syllabus for IES: Indian Engineering Services Examination

MECHANICAL ENGINEERING PAPER-I

(For both objective and conventional type papers)

1. Thermodynamics, Cycles and IC Engines: Basic concepts, Open and Closed systems. Heat and work. Zeroth, First and Second Law, Application to non-Flow and Flow processes. Entropy, Availability, Irreversibility and Tds relations. Claperyron and real gas equations, Properties of ideal gases and vapours. Standard vapour, Gas power and Refrigeration cycles. Two stage compressor. C-I and S.I. Engines. Pre-ignition, Detonation and Diesel-knock, Fuel injection and Carburation, Supercharging. Turbo-prop and Rocket engines, Engine Cooling, Emission & Control, Flue gas analysis, Measurement of Calorific values. Conventional and Nuclear fuels, Elements of Nuclear power production.

2. Heat Transfer and Refrigeration and Air conditioning: Modes of heat transfer. One dimensional steady and unsteady conduction. Composite slab and Equivalent Resistance. Heat dissipation from extended surfaces, Heat exchangers, Overall heat transfer coefficient, Empirical correlations for heat transfer in laminar and turbulent flows and for free and forced Convection, Thermal boundary layer over a flat plate. Fundamentals of diffusive and connective mass transfer, Black body and basic concepts in Radiation, Enclosure theory, Shape factor, Net work analysis. Heat pump and Refrigeration cycles and systems, Refrigerants. Condensers, Evaporates and Expansion devices, Psychrometry, Charts and application to air conditioning, Sensible heating and cooling, Effective temperature, comfort indices, Load calculations, Solar refrigeration, controls, Duct design.

3. Fluid Mechanics: Properties and classification of fluids, Manometry, forces on immersed surfaces, Center of pressure, Buoyancy, Elements of stability of floating bodies. Kinematics and Dynamics. Irrotational and incompressible. Inviscid flow. Velocity potential, Pressure field and Forces on immersed bodies. Bernoulli's equation, Fully developed flow through pipes, Pressure drop calculations,Measurement of flow rate and Pressure drop. Elements of boundary layer theory, Integral approach, Laminar and turbulent flows, Separations. Flow over weirs and notches. Open channel flow, Hydraulic jump. Dimensionless numbers, Dimensional analysis, Similitude and modelling. One-dimensional isentropic flow, Normal shock wave, Flow through convergent - divergent ducts, Oblique shock-wave,Rayleigh and Fanno lines.

4. Fluid Machinery and Steam Generators: Performance, Operation and control of hydraulic Pump and impulse and reaction Turbines, Specific speed, Classification. Energy transfer, Coupling, Power transmission, Steam generators Fire-tube and water-tube boilers. Flow of steam through Nozzles and Diffusers, Wetness and condensation. Various types of steam and gas Turbines, Velocity diagrams. Partial admission. Reciprocating, Centrifugal and axial flow Compressors, Multistage compression, role of Mach Number, Reheat, Regeneration,Efficiency, Governance.

MECHANICAL ENGINEERING PAPER - II

(For both objective and conventional type papers)

5. THEORY OF MACHINES: Kinematic and dynamic analysis of planer mechanisms. Cams. Gears and gear trains. Flywheels. Governors. Balancing of rigid rotors and field balancing. Balancing of single and multi cylinder engines, Linear vibration analysis of mechanical systems. Critical speeds and whirling of shafts Automatic controls.

6. MACHINE DESIGN :Design of Joints : cotters, keys, splines, welded joints, threaded fasteners, joints formed by interference fits. Design of friction drives : couplings and clutches, belt and chain drives, power screws.

Design of Power transmission systems : gears and gear drives shaft and axle, wire ropes.

Design of bearings : hydrodynamics bearings and rolling element bearings.

7. STRENGTH OF MATERIALS: Stress and strain in two dimensions, Principal stresses and strains, Mohr's construction, linear elastic materials, isotropy and anisotropy, stress-strain relations, uniaxial loading, thermal stresses. 

Beams :Bending moment and shear force diagram, bending stresses and deflection of beams. Shear stress distribution. Torsion of shafts, helical springs. Combined stresses, thick-and thin-walled pressure vessels. Struts and columns. Strain energy concepts and theories of failure.

8. ENGINEERING MATERIALS :Basic concepts on structure of solids. Crystalline materials. Detects in crystalline materials. Alloys and binary phase diagrams. Structure and properties of common engineering materials. Heat treatment of steels. Plastics, Ceramics and composite materials. Common applications of various materials.

9. PRODUCTION ENGINEERING :

Metal Forming : Basic Principles of forging, drawing and extrusion; High energy rate forming; Powder metallurgy.

Metal Casting : Die casting, investment casting, Shall Moulding, Centrifugal Casting, Gating & Riser design; melting furnaces.

Fabrication Processes : Principles of Gas, Arc, Shielded arc Welding; Advanced Welding Processes,

Weldability: Metallurgy of Welding.

Metal Cutting : Turning, Methods of Screw Production, Drilling, Boring, Milling, Gear Manufacturing,Production of flat surfaces, Grinding & Finishing Processes. Computer Controlled Manufacturing Systems-CNC, DNC, FMS, Automation and Robotics.Cutting Tools Materials, Tool Geometry, Mechanism of Tool Wear, Tool Life & Machinability; Measurement of cutting forces. Economics of Machining. Unconventional Machining Processes. Jigs and Fixtures. Fits and tolerances, Measurement of surface texture, Comparators Alignment tests and reconditioning of Machine Tools.

10. INDUSTRIAL ENGINEERING :

Production Planning and Control : Forecasting - Moving average, exponential smoothing, Operations, scheduling; assembly line balancing, Product development, Break-even analysis, Capacity planning,PERT and CPM.

Control Operations : Inventory control ABC analysis, EOQ model, Materials requirement planning. Job design, Job standards, Work measurement, Quality Management - Quality analysis and control.

Operations Research : Linear Programming - Graphical and Simplex methods, Transportation and assignment models. Single server queuing model. Value Engineering : Value analysis for cost/value.

11. ELEMENTS OF COMPUTATION :

Computer Organisation, Flow charting, Features of Common computer Languages - FORTRAN, d Base III, Lotus 1-2-3, C and elementary Programming.