Mechanical Engineering Tutorial Blog

Freelance Engineering Service

noreply@blogger.com (PD Patel) — Thu, 18 Feb 2021 03:04:00 +0530

We are a group of engineers having vast experience in the milk dairy piping engineering industry.

We are providing the following services in Canada, Ontario:

1. Pipe stress analysis.

2. Equipment and Piping layout preparation.

3. Static equipment analysis

4. Platform structure analysis.

5. Pipe rack structure analysis.

6. Piping skid design.

Apart from the above,

We help customers to select process equipment as per process requirements.

We are proficient to establish milk process plants and guides to pump selection, Heat exchanger selection, the correct instrument as per process, selection of valve, etc.

For more information contact:

priyamp1994@gmail.com

+1 226-788-9342 (Priyam Patel)

Autodesk Autocad P&ID Overview

noreply@blogger.com (PD Patel) — Sun, 25 Feb 2018 22:07:00 +0530

Hello, Autocad users, this post is for you if you are making piping and instrument diagram on autocad with manual commands of autocad.

Autodesk P&ID Overview: Autodesk p&id is developed by autodesk specially for industries which are working on design and erection of large process plant of oil and gas or food and process or any other. so let discuss how this autodesk product is different from autocad and why industries moving on autodesk p&id.

First of all p&id is the diagram which is very important document for process plant which describe all the detail of process, instrument, mechanical components, pipe spec etc. Process flow diagram is the basic of p&id and is made by process engineer. than mechanical engineer make mechanical & instrument diagram or piping & instrument diagram.

This p&id drawing contain number of instruments like temperature measurement, pressure indicator and measurement...etc. All this instruments are used at different location like utility plant, process plant or ETP area. So next challenge is to accurately measure this quantity with location. which is not possible by autocad. So autocad p&id is the only option. here I will describe some basic features of this software using video tutorial and explanation.

1. It is very much easy to make line of different services(air, electrical, steam, water, etc...). no extra work need to assign color, flow direction, and even line number can easily assign according to our required format.

2. It is very much easy to pick and place desirable equipment symbol according to requirement. just select symbol from tool palettes drag and drop to work space.

3. It is very much easy to add valve to particular line as the method is same just pick and place. software will assign valve number automatically according to predefined conditions.

4. It will generate project report in backstage according to our requirement.

5. Project report contain complete boq in particular format so we just need to make summary from default generated report. I have explained this is how much easy using pivot table to summarize data.

6. At the end we can simultaneously generate both p&id diagram and also boq.

As per explained benefits you can easily save time and effort by smart way of work!

get connected for more video tutorial like how to make different service line, valve tag format, etc... according to our requirement.

Lesson 1 : Basic Of Pipe Stress Analysis Using Caesar II

noreply@blogger.com (PD Patel) — Tue, 8 Mar 2016 21:37:00 +0530

From this tutorial you can learn basic concept of caesar 2 software, how to start new file and to create custom unit file for different project.

This tutorial also prove basic theory of strength of material.

Example show cantilever beam of 10m and having 2mm deflection at one end, other end is fix called as anchor in caesar.

Conclusion: To make 2mm deflection how much force required, that we can see from analysis. and you can also make manual calculation for that to compare.

F=Kx

where K= 3EI/L^3 N/mm

x= 2mm

If you have any doubt than comment...

Innovative Flooded Steam Heat Exchanger - A Unique Vertical Steam HeatExchanger

noreply@blogger.com (PD Patel) — Sat, 23 Jan 2016 19:12:00 +0530

Innovative Flooded Steam Heat Exchanger
If you are a designer that works for consultant engineer or mechanical you might have come across steam network system . Steam piping design is done the same way over the last 100 years or so. The traditional way of design those steam heating system needs a lot of components like 2 (1/3-2/3) pressure reducing valve, 2 (1/3-2/3) control-valve on the steam heat exchanger, a steam relief valve hook to the roof which need maintenance annually and a dedicate condensate return pump with a vent pipe to the roof to eliminate all the flash in return condensate line in order to avoid any water hammer.

New steam heating system needs less equipment

No more pressure reducing valve, no more condensate pump and no more safety relief valve.

This innovative vertical steam heat converter solution that not only avoid all those previous pieces of equipment but gives also energy savings up to 15%!

The steam system consist of using a vertical heat exchanger, build for steam process, with a small control valve install on the condensate return line. By doing so, they flood the heat exchanger. That allows them to extract not only the latent heat but also the sensible heat which you don’t do when you use a traditional horizontal heat exchanger system. And because they work on full pressure in the steam inlet, they don’t need a vacuum breaker, so they don’t inject oxygen in you return lines anymore.

It requires no safety valve to the roof

The vertical steam heat exchanger comes with an ASME (CRN for Canada) stamp for high pressure vessel on the heat exchanger and all the other components. This way the safety valve is not needed.

There is over 400 installations around United States and Canada. Mostly use in Hospitals, Colleges &Universities and some industry, this unique concept is the new way of designing steam network.

And the big question is why we didn’t do this before?

Well if you take a look at the traditional manufacturer in the steam business, not only they offer heat exchanger concepts but also all the components needed to make this work, so by pushing this type of concept (flooded steam heat exchanger) they will lose a lot of return business in maintenance over years. Like the pressure reducing valves and steam condensate pumps.

Maxi-Therm is a new player in the steam market, not only they manufacture building heat and domestic hot water system but also a clean steam generator and a condensate mixer that avoid the needs of multiple condensate return lines. They simply offer all the solutions to have a 100% close loop on steam with no vents to the roof or the wall.

To know more about Maxi-Therm visit www.maxi-therm.net. (514) 351-1001

PDMS Tutorial: Column Design In AVEVA PDMS

noreply@blogger.com (PD Patel) — Sun, 29 Nov 2015 19:07:00 +0530

PDMS Tutorial: Column Design In AVEVA PDMS

PDMS Tutorial: Equipment Design And Nozzle Orientation In Aveva PDMS

noreply@blogger.com (PD Patel) — Sun, 29 Nov 2015 18:55:00 +0530

This Video Show How To Make Horizontal Drum And Nozzle Orientation.

NDT- Non Destructive Testing

noreply@blogger.com (PD Patel) — Thu, 24 Sep 2015 08:37:00 +0530

Nondestructive testing - NDT - use test methods to examine an object, material or system without impairing its future usefulness. Non-destructive testing is often required to verify the quality of a product or a system. Commonly used techniques are

AET - Acoustic Emission Testing

Acoustic Emission Testing takes advantage of the sharp sound that PCCP emits when it breaks or slips to identify areas of active distress within a construction. AET can be used to verify the structural integrity of pressure vessels, spheres, high temperature reactors and piping, coke drums, above ground storage tanks, cryogenic storage tanks and more. The inspection is executed externally and shut-down of the process may often not be necessary.

ART - Acoustic Resonance Testing

After an impact a specimen will vibrate in certain characteristic modes and frequencies that can be measured by a microphone or laser vibrometer. Acoustic sonic and ultrasonic resonance analysis is a non-destructive testing technique that allows testing of a wide range of test objects. Typical detecting faults are cracks, cavities, detached layers, material inconsistencies, hardness deviation in materials.

ET - Electromagnetic Testing

Electromagnetic testing is the process of inducing electric currents and/or magnetic fields inside a test object and observing the response. A defect in the test object may be detected where electromagnetic interference creates a measurable response.

IRT - Infrared Testing

Infrared testing is a technique that uses thermography, an infrared imaging and measurement camera, to see and measure infrared energy emitted from an object. Can be used to heat development, lack of insulation, thin walls in constructions and more.

LT - Leak Testing

Techniques used to detect and locate leaks in pressure containment parts, pressure vessels, and structures. Leaks can be detected by using liquid and gas penetrant techniques, electronic listening devices, pressure gauge measurements or soap-bubble tests.

MT - Magnetic Particle Testing

Magnetic particle testing is accomplished by inducing a magnetic field in a ferromagnetic material and then dusting the surface with iron particles. The surface will produce magnetic poles and distort the magnetic field in such a way that the iron particles are attracted and concentrated making defects on the surface of the material visible.

PT - Dye Penetrant Testing

The dye penetrant testing can be used to locate discontinuities on material surfaces. A highly penetrating dye on the surface will enter discontinuities after a sufficient penetration time, and after removing the excess dye with a developing agent, the defects on the surface will be visible.

RT - Radiographic Testing

Radiographic testing can be used to detect internal defects in castings, welds or forgings by exposure the construction to x-ray or gamma ray radiation. Defects are detected by differences in radiation absorption in the material as seen on a shadow graph displayed on photographic film or a fluorescent screen.

UT - Ultrasonic Testing

Ultrasonic testing uses high frequency sound energy to conduct examinations and make measurements. Ultrasonic inspection can be used for flaw detection/evaluation, dimensional measurements, material characterization, and more.

VT - Visual Testing (VI - Visual Inspection)

Visual testing or inspection offers a wide range of options to secure proper system or product quality.

Utility Piping | Steam Piping - Steam Heating

noreply@blogger.com (PD Patel) — Tue, 22 Sep 2015 14:15:00 +0530

In Previous Article We seen the different use and types of steam.

We know the dry saturated steam is generally used in pipe heating process.

Steam is one of the most common and effective heat transfer mediums used in industry, but it is not the only medium available. Other fluids such as hot water and oil are also used for indirect heating in heat exchangers.

So following are the advantages of steam heating:

In case of heating with hot water it only loose sensible heat around 17kcal/hr But if we use dry saturated steam then it loose latent heat around 539kcal/hr.

So we can see the use of the steam is more preferable in case of pipe heating.

There are different way of heating:

Mainly steam tracing and Pipe jacketing are use:

1. Steam Tracing:

As shown in figure in a steam tracing tracer pipe is bounded around the base pipe.
There are number of tracer are used according to the requirement.
Size of the tracer are varied from 1/2 inch to 1 inch.
Copper is costly so carbon steel used.
Expansion loop in the tracer is provided at every 30 meter.
Tracer are generally locket at bellow of the pipe.

2. Jacketed Heating:

It is mostly use for heating purpose.

There are Two Types of jacketing:
Partial Jacket and Fully Jacket.

Spacer are used at regular interval to maintain distance between pipe and jacket.

In a full jacketing all the pipe element to be jacketed like elbow and tee, flange...etc.

In case of individual jacketing it is not long more than 6m due to thermal expansion.
Jumper is used in case of partial jacketing for transfer of steam.

Utility Piping | Steam Piping - Basic Of Steam

noreply@blogger.com (PD Patel) — Tue, 22 Sep 2015 14:14:00 +0530

What Is Steam

In a simple word Steam is the gas formed when water passes from the liquid to the gaseous state.

The process of formation of steam can be explained as,

In liquid water, H2O molecules are constantly being joined together and separated. As the water molecules are heated, however, the bonds connecting the molecules start breaking more rapidly than they can form. Eventually, when enough heat is supplied, some molecules will break free. These 'free' molecules form the transparent gas we know as steam, or more specifically dry steam.

So there are main two form of the steam: Dry steam and wet steam

Steam is Called Dry steam when all its water molecules remain in the gaseous state. It's a transparent gas.

And is called as Wet Steam When Is Contain water particles in it.

Because there are various form of the steam so according to the phase of steam use is different.

Commonly Steam used For or Principal Application Of Steam

Power generation eg.

Steam Turbine

Steam for heating in two way: Direct Heating and Indirect Heating

eg. Various Types of heat Exchangers

Steam as Motive Fluid

eg. Steam Ejector

Steam also used for cleaning purpose

eg. Soot Blower to clean boiler piping

Steam For Moisturization

Steam Can Also used for Humidification

There Are Various Phase Of Steam:

1. Dry Saturated Steam

Generally used for heat transfer because when it change phase from vapour to liquid it release large amount of energy

2. Wet Steam

3. Superheated Steam

Superheated steam is created by further heating wet or saturated steam beyond the saturated steam point. This yields steam that has a higher temperature and lower density than saturated steam at the same pressure. Superheated steam is mainly used in propulsion/drive applications such as turbines, and is not typically used for heat transfer applications.

4. Flash Steam

Flash steam is a name given to the steam formed from hot condensate when the pressure is reduced.

High temperature condensate contains high energy that cannot remain in liquid form at a lower pressure because there is more energy than that required to achieve Saturated water at the lower pressure. The result is that some of the excess energy causes a % of the condensate to Flash.

The greater the pressure difference, the larger the amount of flash steam generated at discharge.

Vacuum Steam

Vacuum steam is the general term used for saturated steam at temperatures below 100°C.

Use of vacuum steam requires careful temperature and pressure reading. To determine steam temperature, referring to a steam table such as the one above is recommended.

Cooling Tower

noreply@blogger.com (PD Patel) — Fri, 18 Sep 2015 09:28:00 +0530

Cooling tower are very important part of many chemical plants. primary task of cooling tower is to reject heat into the atmosphere.

Cooling Tower Type:

Mainly there is two type : Natural draft and mechanical draft

Natural draft cooling tower are large in construction and mainly use for water flow rate more than 45000 m^3/hr.

There are three arrangement in mechanical draft:

1. Counter Flow induced draft

2.counter flow forced draft

3.cross flow induced draft

Main component of cooling tower:

Frame and casing, fill, cold water basin, drift eliminator, air inlet, louvers, nozzles and fan.

Tower Material:

In early days wooden tower made but now a day variety of material are used :

In basic material Galvanized steel, various grade of stainless steel, glass fibre and concrete are widely used.

Large tower some time made of Concrete.

Plastic are widely used for fill.

Cooling Tower Performance:

The important parameter for the performance of cooling tower are:

1. Range which is the difference of the hot water inlet and the cooling water outlet.

2.Approach is the difference of the cooling water outlet temp and wet bulb temp.

3.Cooling tower efficiency:

= Range/(Range+Approach)

4. Evaporation Loss, Blow down Loss.

5. Liquid/Gas Ratio.

If you have any query Than Comment Bellow

Pipe Material For Pipe And Pipe Elements

noreply@blogger.com (PD Patel) — Mon, 14 Sep 2015 22:59:00 +0530

MATERIAL SELECTION OF PIPING COMPONENTS

The first thing to be considered is the selection of suitable material for the service. The selection of piping material requires knowledge of corrosion properties, strength and engineering characteristics, relative cost and availability.
The main process considerations in the material selection are the corrosion properties of the fluid, the pressure temperature conditions of the service and the nature of the service.

The Piping Designer selects/designs the piping components based on the mechanical properties such as the following.

Yield strength

Ultimate strength

Percentage elongation

Impact strength

Creep-rupture strength

Fatigue endurance strength

Following Are The Common Material For Piping Elements:

1. Metalic

Ferrous

Cast iron

carbon Steel

Alloy Steel

Stainless Steel

Non Ferrous

Copper And Copper Alloy

Aluminium And Aluminium Alloy

Nickel And Nickel Alloy

Lead

2. Non Metalic

PVC

CPVC

HDPE

FRP

PTEF

LDPE

LLDPE

Glass

Ceramic

Cement

3.Lined

MSGL

MSRL

MS PTEF Lined.

MS Ceramic Lined.

MS Cement Lined.

Heat and Mass Transfer Interview Question

noreply@blogger.com (PD Patel) — Fri, 4 Sep 2015 22:05:00 +0530

Following are the three way of heat transfer:

Conduction

Convection

Radiation

What is Fourier law of heat conduction?

Concept of critical thickness of insulation.

What is Fin? Where it is require and why?

Heat Transfer By convection.

Free convection and force convection.

Newtons law of cooling.

Thermal Boundary layer.

What is Difference between free and force convection.

Heat Exchanger:

What you mean by heat exchanger?

Classification of the heat exchanger.

Heat exchanger analysis.

What is meaning of LMTD for heat exchanger.

What is meaning of Effectiveness and NTU for Heat Exchanger.

Heat Transfer by radiation:

How heat is transfer in radiation effect.

Concept of the black and white body.

Absorptivity, Reflectivity, and Transmissivity.

How Radiation transfer between two bodies.

What is Shape Factor?

Fluid Mechanics Interview Question

noreply@blogger.com (PD Patel) — Thu, 3 Sep 2015 20:30:00 +0530

Fluid mechanics is the science which deals with the fluid in rest or in motion.

It can be classified in static, kinematics and dynamic.

Fluid static deal with fluid at rest.

Fluid kinematics deal with fluid in motion without considers any pressure effect.

In Fluid Dynamics Fluid is in Motion and pressure effect is consider.

Following are some question which can be ask in Interview.

What are the different between liquid and gases?

Property of the fluid:

Density, Specific Weight, Specific Volume, Specific Gravity, Dynamic Viscosity, Kinematic Viscosity

What Is Newtons law of viscosity?

What are the changes in viscosity with temperature?

What is Cohesion, Adhesion and Surface Tension.?

What is Bulk modulus of elasticity?

What is pressure head? And what are the different types of pressure?

Which is the pressure measuring instrument?

What is buoyancy? Condition for equilibrium of floating Body.

What are the different types of flow?

Explain steady and unsteady Flow, uniform and non-uniform flow, Laminar and turbulent flow etc.

What is the use of Bernoulli Equation?

Basic Of Steam Turbine

noreply@blogger.com (PD Patel) — Wed, 2 Sep 2015 21:06:00 +0530

The steam turbine is universally used as prime mover in steam power plants.

Flow over Blades:

The steam turbine obtains its motive power from the change of momentum of a jet of steam flowing over a curved blade. The steam jet, in moving over the curved surface of the blade, exerts a pressure on the blade owing to its centrifugal force. This centrifugal force is exerted normal to the blade surface as shown in figure and acts along the whole length of the blade.

The resultant of these centrifugal forces plus the effect of change of velocity is the motive force on the blade. It should be realized that the blade obtains no motive form any impact of the jet, because the blade is so designed that the steam jet will glide on and off the blade without any tendency to strike it. In principle, it is analogous to a train passing around a railway curve. The train exerts a radially outward force on the line due to the centrifugal force.

Moving and Fixed Blades

In a steam turbine, a number of small blades are fixed to the ring of a revolving wheel or rotor. Jets of steam of a high velocity are obtained by expansion through nozzles and are directed on to the blades. The effective force of these jets, acting on the blades, rotates the wheel.

In modern turbines several of the wheel of moving blades are keyed to the same shaft, having a ring of fixed blades between each wheel of moving blades. These fixed blades are fixed to the turbine casing. Their object is to receive the steam jet from the moving blade ring and to divert it on to the next ring of moving blades by changing its direction as shown. This diversion may continue over several rings of moving and fixed blades until the whole of the kinetic energy of the steam jet is expended.

Press Working Operations And Terminology

noreply@blogger.com (PD Patel) — Mon, 31 Aug 2015 17:56:00 +0530

Press working may be defined as, a manufacturing process by which various components are made from sheet metal. This process is also termed as cold stamping. The machine used for press working is called a press.

The main features of a press are:

A frame which support a ram or a slide and a bed, a source of mechanism for operating the ram in line with and normal to the bed.
The ram is equipped with suitable punch/punches and a die block is attached to the bed.
A stamping is produced by the downward stroke of the ram when the punch moves towards and into the die block.
The punch and die block assembly is generally termed as a “die set” or simple as the “die”

Press working operations:

The sheet metal operations done a press may be grouped into two categories.

1: Cutting operations

2: Forming operations

In cutting operations the work piece is stressed by its ultimate strength. The stresses caused in the metal the applied forces will be shear stresses. The cutting operations include:

(a) Blanking (b) Punching (c) Notching

(d) Perforating (e) Trimming (f) Shaving

(g) Slitting (h) Lancing

In forming operations , the stresses are below the ultimate strength of the metal , in this operation , there is no cutting of the metal but only the contour of the work piece is changed to get the desired product.

The forming operations include:

(a) Bending (b) Drawing (c) Squeezing

A simple cutting die used for punching and blanking operation as shown:

1: Bed:

The bed is the lower part of the press frame that serves as a table to which a

Bolster plate is mounted.

2: Bolster Plate:

This is a thick plate secured to the press bed , which is used for locating and

supporting the die assembly. It is usually 5 to 12.5 cm thick.

3: Die Set:

It is unit assembly which incorporates a lower and upper shoe, two or more guide parts and guide part bushings.

4: Die Block:

It is a block or a plate which contains a die cavity

5: Lower Shoe:

The lower shoe of the a die set is generally mounted on the bolster plate of a press. The die block is mounted on the lower shoe, also the guide post are mounted on it.

6: Punch :

This is male component of a die assembly, which is directly or indirectly moved by and fastened to the press ram or slide.

7: Upper Shoe:

This is the upper part of the die set which contains guide post bushings.

8: Punch Plate :

The punch plate or punch retainer fits closely over the body of the punch and holds it in proper relative position.

9: Back up Plate:

Back up plate or pressure plate is placed so that intensity of pressure does

not become excessive on punch holder. The plate distributes the pressure

over a wide area and the intensity of pressure on the punch holder is reduced

to avoid crushing.

10: Stripper:

It is a plate which is used to strip the metal strip from cutting a non-cutting

Punch or die. It may also guide the sheet.

Machines used in Tablet Manufacturing

noreply@blogger.com (PD Patel) — Sat, 29 Aug 2015 11:37:00 +0530

Common machines used in Tablet manufacturing Process:

1. Granulation and Blending
2. Compression
3. Coating
4. Packaging

1. Granulation and Blending:

A. Granulation Equipments:

Fluid Bed Dryer (FBD):

Rapid Mixer Granulator (RMG):

Oscilliting Granulator:

Tray Dryers:

Multi Mill:

Inprocess Bulk Container (IBC):

Vibro Sifter:

B. Blenders:

Octagonal Blender

Cage Blender:

Mass Mixers:

V type Blenders:

Double Cone Blender:

Double Rotary Tablet Compression Machine

noreply@blogger.com (PD Patel) — Sun, 23 Aug 2015 11:13:00 +0530

Double Rotary Tabletting Machine

Double Rotary Machine

Double Sided Tabletting Press Machine is used to produce round, double-sided engraved or irregular tablets in a wide variety of shapes.

Double sided rotary press consists of a rotating multi station die table producing two tablets per station for each revolution.

Double Sided Tabletting Press combines in one machine the sophistication, which today’s Tabletting requirements demands together with highly functional mechanical design and components.

Very rigid gun metal Feed Frame with sufficient height to avoid spill over of powder. Turret rotates on needle roller thrust bearing, which is immersed in oil for frictionless rotation.

Single Rotary Tablet Compression Machine

noreply@blogger.com (PD Patel) — Sun, 23 Aug 2015 11:10:00 +0530

Single Rotary Tabletting Machine

In Single Rotary Machine top half of the machine is with S.S. hood and acrylic covers and lower half of the machine complete with mat finished S.S. Covers. This reduces the noise level and to & fro flow of dust between compression zone and M/c room.

A single sided rotary press consists of a die table producing single tablet per station for each revolution.

No foundation require due to anti vibration mounting.

Turret is made of highly ductile SG Iron casting.

Large paint free compression zone with plenty of space for ease of cleaning & accessibility of components.

Electronic total output counter is provided on the control panel.

It is easy to operate and maintain the machine.

Higher Turret speed gives higher output than standard machine.

Friction plate on cam plate to minimize wear & tear of cam track, which also facilitates its easy replacement.

Upper punch dust covers to avoid collection of dust on punch head.

Tablet rotary punch machine are designed with the following basic components:

Hopper: It is used to hold the materials (drug or the drug with excipients/granules) to be compressed and supply the material to the die and removes the tablet after its compression

Dies: Dies defines the shape and the size of the tablet by allowing the lower and upper punch to come close together to compress the material.

Lower and upper punches: These are used for compressing of the materials (drug or the drug with excipients/granules) within the dies.

Cam track: This is the component used forguiding the movement of the punches.

Capacity regulator: To adjust the position of the lower punch to accommodate the required quantity of materials by the die.

Ejection regulator: To adjust the position of the lower punch, so that its highest position is at par with the surface of the die.

Driving wheel: It helps in the movement of the lower punch, the upper punch and hopper shoe and also check their movement.

Types of Tablet Compression Machines

noreply@blogger.com (PD Patel) — Sun, 23 Aug 2015 10:31:00 +0530

Single Rotary Tabletting Machine

Single Rotary Machine

Double Rotary Tabletting Machine

Double Rotary Machine

Tablet Press Machines

Tablet Press Machine

Piping Material : IIT Mumbai Piping Material Free Download

noreply@blogger.com (PD Patel) — Tue, 18 Aug 2015 20:18:00 +0530

Piping study often referred as ‘half science & half art’. Art part includes visualization and creativity, while Science part includes following certain established norms. And both these parts involve lot of dedication, risk taking ability and discipline

Scope for Piping Engineering

Chemical Process Industry

Petroleum & Petrochemical Industry

Pharmaceutical Industry

Power Plant

Long Distance LNG/LPG/CNG Piping System

Irrigation Project

Project & Construction Companies

Importance of Piping Engineer

A Piping Engineer plays an important role from "Concept to Commissioning" in all sector of process and related industries. With increasing emphasis on transportation of petroleum products, natural gas, corrosive & hazardous chemicals through undergoing and long distance pipelines, the requirement of skill Piping Engineering is increasing day by day.

IIT Mumbai Piping Material :

Content:

Introduction to Piping Industry.
Role & Scope of a Piping Engineer in various fields of industry.
Overview of International codes and standards.
Guidelines of various process plants and their drafting requirements.
Basic fundamentals and concepts of Piping design and drafting.
Basics of Plot plan development.
Basics of equipment layout development.
Detailing of Pipe rack and Yard piping.
Development of Equipment & Piping layouts.
Detail study of Piping General Arrangement Drawing (Piping GAD)
Details of Process piping, System piping, Utility piping etc.
Preparation of Isometric drawings and Bill of Materials
Piping Material Selection & Specification and MOC
Preparation of Nozzle Orientation.
Introduction of instrumentation and automation (PLC, SCADA, DCS etc)
Stress analysis theory, Calculation and software practice with case study.
Guidelines to preparation of as built drawings.
Pipe costing , Thermal insulation & heat tracing
Introduction to Fluid dynamics and line sizing
Statutory rules regulation & industrial safety (HAZOP & HAZAN) 
Supports, valves, pumps, gaskets, flanges, and other pipe fitting elements
Introduction to 3-D Designing Software and Modeling
Introduction to Stress Analysis Software

IF You Want To Get This Material Free Of Cost Than Please Comment Bellow With Email ID.I Will Send You As Soon As Possible.

Mechanical Engineering Interview Question: Engineering Drawing Interview Question

noreply@blogger.com (PD Patel) — Wed, 12 Aug 2015 11:14:00 +0530

1.Define engineering drawing.
Engineering drawing is a graphical language of an engineer to convey one’s ideas most effectively, easily, conveniently and with high speed.
So Engineering drawing is a starting point of all engineering branches such as Mechanical, Production, Civil, Electrical, Electronics, Computer science, Chemical etc.
It is spoken, read, and written in its own way. Engineering drawing has its own grammar in terms of projections, conventional representations, types of lines, abbreviations, symbols and various geometric constructions.

2. Name different drawing instruments.
Drawing board, drawing sheet, mini-drafter, scale, pencil and sand paper block, cello-tape, eraser and compass.

3. What are the standard sizes of drawing sheets according to I.S.I. and which is suitable for drawing work?

The standard size of sheets according to I.S.I. are
A0 (1189 X 841),
A1 (841 X 594),
A2 (594 X 420),
A3 (420 X 297),
A4 (297 X 210) and
A5 (210 X 148).

4.List out the contents of title block.
The title block should contain the following information.
(i) Name of the institution
(ii) Title of drawing
(iii) Name, Branch, section and Roll no. of the student
(iv) Type of scale used
(v) Drawing number
(vi) Type of symbol for the method of projection

5. What is lettering?
The art of writing the alphabets A, B, C,…….Z and numbers such as0,1, 2, 3…… etc. is known as lettering.

6.What are the main requirements of lettering?
1) The knowledge of shape and proportion of each letter.
2) The knowledge of the order and direction of the strokes used in making letters.
3) The knowledge of the general composition of letters.

7. What is dimensioning?
The art of writing the various sizes on the finished drawing of an object is known as dimensioning.

8. What is the importance of dimensioning?
1) Dimensioning conveys all the sizes and other necessary information to completely draw the object.
2) It also contains information with regard to manufacturing processes and inspection requirements.
3) The dimensioning also includes tolerances necessary for the correct functioning of the parts in the assembly.

9. What is a scale?
A scale is defined as the proportion by which we keep same or reduce or increase the actual size of the object on a drawing.
Scale = Size taken on the drawing : Actual size

10. What are various types of scales used in drawing?

There are three types of scales used in drawings.
1) Full size scale:-The scale in which the actual measurements of the object are drawn to same size on the drawing is known as full size scale. For example 1:1

2) Reducing scale: – The scale in which the actual measurements of the object are reduced to some proportion is known as reducing scale. For example 1:4

3) Enlarging scale: – The scale in which the actual measurements of the object are increased to some proportion is known as enlarging scale. For example 2:1

11. What are different types of orthographic projections?

There are four types of orthographic projections.
(i) First angle projection
(ii) Second angle projection
(iii) Third angle projection
(iv) Fourth angle projection

Common Mechanical Interview Question/Answer For Fresher

noreply@blogger.com (PD Patel) — Thu, 6 Aug 2015 12:11:00 +0530

What are Bevel Gears and what are its types?

Bevel gears are the type of gears in which the two shafts happen to intersect. The gear faces which are tooth bearing are conical in shape. They are generally mounted on shafts which are 90 degrees apart but they can be made to work at other angles as well. The bevel gears are classified into the following types on the basis of pitch surfaces and shaft angles:

> Mitre Gears: These types of gears are similar to each other ie. they have the same pitch angles and contain the same number of teeth. The shaft axes intersect at 90 degrees angle.

> Angular bevel gears: When two bevel gears connect at any angle apart from 90 degrees.

> Crown bevel gears: When the two shaft axes intersect at an angle greater than 90 and one of the bevel gears have a pitch angle of 90 degrees they are known as crown bevel gears.

> Internal bevel gears: In these type of gears the teeth on the gears is cut on the inside area of the pitch cone.

What are the different values that need to be determined in order to design a cylinder for an ICE?

The following values are needed to be determined:

> Thickness of the cylinder wall: The cylinder walls in an engine is made witness to gas pressure and the side thrust of a piston. This results in two types of stresses: longitudinal and circumferential stress. Both the types of stresses are perpendicular to each other and hence it is aimed to reduce the resulting stress as much as possible.

> Length and bore of the cylinder: The length of the cylinder and the length of the stroke is calculated on the basis of the formula: length of cylinder L = 1.15 times the length of the stroke (l). L = 1.15(l)

> Cylinder flange and studs: The cylinders are always cast integral as a part of the upper crankcase or in some cases attached to it by means of nuts and bolts. The flange is integral to a cylinder and henceforth its thickness should be greater than that of the cylinder wall. The thickness of flange should generally be between 1.2t-1.4t where t is the cylinder thickness.

The stud diameter is calculated by equating gas load ( due to max pressure ) to the grand total of all the resisting forces of the studs.

What are considerations taken into account while creating a piston head?

The piston head is designed on the basis of the following considerations:

> The crown should have enough strength to absorb the explosion pressure inside the engine cylinder.

> The head must always dissipate the heat of the explosion as quickly as possible to the engine walls. The thickness of the head is calculated on the basis of another formula which takes into consideration the heat flowing through the head, the conductivity factor of the material. The temperature at the center and edges of the head.

> The thickness of the piston head is calculated on the basis of the Grashoff`s formula which takes into consideration the maximum gas pressure of an explosion , the permissible bending and the outside diameter of the piston.

General Mechanical Interview Question/Answer For Fresher

noreply@blogger.com (PD Patel) — Thu, 6 Aug 2015 12:08:00 +0530

During the design of a friction clutch what are the considerations that should be made?

In order to design a friction clutch the following points must be kept in mind:

> The material for the contact surfaces must be carefully selected.

> For high speed devices to minimize the inertia load of the clutch, low weight moving parts must be selected.

> The contact of the friction surfaces must be maintained at all the times without the application of any external forces.

> Provisions for the facilitation of repairs must be there.

> In order to increase safety the projecting parts of a clutch must be covered.

> A provision to take up the wearing of the contact surfaces must be present.

> Heat dissipaters to take away the heat from the point of contacting surfaces must be there.

What are the different types of brakes and explain them briefly?

Brakes can be classified on the basis of their medium used to brake, they are as follows:

> Hydraulic Brakes: These brakes as their name suggest use a fluid medium to push or repel the brake pads for braking.

> Electric Brakes: These brakes use electrical energy to deplete or create a braking force.

Both the above types of breaks are used primarily for applications where a large amount of energy is to be transformed.

> Mechanical Brakes: They can be further classified on the basis of the direction of their acting force: Radial Brakes: As their names suggests the force that acts on the brakes is of radial direction. They can further be classified into internal and external blades. Axial Brakes: In these types of brakes the braking force is acting in an axial direction as compared to radial brakes.

On what basis can sliding contact bearings be classified? Explain?

Sliding contact bearings can be classified on the basis of the thickness of the lubricating agent layer between the bearing and the journal. They can be classified as follows:

> Thick film bearings: These type of bearings have their working surface separated by a layer of the lubricant. They are also known as hydrodynamic lubricated bearings.

> Thin film bearings: In this type of bearings the surfaces are partially in direct contact with each other even after the presence of a lubricant. The other name for such type of bearings is boundary lubricated bearings.

> Zero Film Bearings: These type of bearings as their name suggests have no lubricant present between the contact layers.

> Externally or hydro statically pressurized lubricated bearings: These bearings are able to without any relative motion support steady loads.

What are the basis on which the best material for Sliding Contact Bearings manufacturing?

Some of the important properties to lookout for in the material for sliding contact bearings are as follows:

> Compressive Strength: In order to prevent the permanent deformation and intrusion of the bearing the material selected should be possess a high compressive strength to bear the max bearing pressure.

> Fatigue Strength: the material selected for the bearing should be able to withstand loads without any surface fatigue cracks getting created. This is only possible if the material has a high level of fatigue strength.

> Comfortability: The material should be able to adjust or accommodate bearing inaccuracies and deflections without much wear and heating.

> Embeddability: The material should allow the embedding of small particles without effecting the material of the journal.

> Bondability: The bearings may be created by bringing together ( bonding ) multiple layers of the material. Due to the above reason the bondability of the material should be sufficiently high.

> Thermal conductivity and corrosion resistance: Thermal conductivity is an essential property for bearing materials as it can help in quickly dissipating the generated heat. Also the material should have a level of corrosion resistance against the lubricant.

Briefly explain the advantages of Cycloidal and Involute gears?

The advantages of the Cycloidal gears are as follows:

> Having a wider flank as compared to Involute gears they are considered to have more strength and hence can withstand further load and stress.

> The contact in case of cycloidal gears is between the concave surface and the convex flank. This results in less wear and tear.

> No interference occurs in these types of gears.

The advantages of Involute gears are as follows:

> The primary advantage of involute gears is that it allows the changing of the centre distance of a pair without changing the velocity ratio.

> The pressure angle remains constant from start to end teeth, this results in less wear and smooth running of the gears.

> The involute gears are easier to manufacture as they can be generated in a single curve ( the face and flank ).

How can the reaction of support of a frame be evaluated?

Generally roller or hinged support are used to support the frames. The conditions of equilibrium are used to determine the reaction support of a frame. The condition of equilibrium takes place when the sum of the horizontal and vertical forces sum equal to zero. The system must form a state of equilibrium even after considering the external loads and the reactions at the supports. For equilibrium to be prevalent in the system the following conditions are required to be in occurrence:

> Summation of V = 0. This implies that the summation of all the forces in the vertical direction results to zero.

> Summation of H = 0 . This implies that the total of all the forces acting in horizontal direction is also zero.

> Summation of M = 0. The sum of all the moment of forces around a point must be zero.

Explain in an orderly manner how the force in the member of a truss be detected using the method of joint.

The steps required to calculate the force are as follows:

> The reaction at the support has to be first calculated.

> Once the reaction is calculated the direction of force of the member is made to make it tensile. On getting the result to be negative the direction assumed is wrong and this implies the force being compressive in nature.

> A joint needs to be selected whose 2 members are not known. The lami`s theorem is used on the joint on which less than three forces are acting.

> After the above process is complete the free body diagrams of the joint needs to be made. Since the system is in equilibrium the condition of Summation of V and H must result in zero.

> After the above step the resolution of forces method needs to be used on the joint on which more than 4 forces are acting.

In order to derive the torsional formulas what are the assumptions taken?

The torsion equation is derived on the basis of following assumptions:

> The shaft material is uniform, throughout the shaft.

> Even after loading the shaft circular remains circular.

> After the application of torques the plain section of a shaft remains plain.

> Any twist that occurs in the shaft remains uniform and constant.

> After the application of torque the distance between any two cross-sectional references remains constant.

> The elastic limit value of a shaft is never exceeded even after the shear stress induced because of torque application.

General Mechanical Interview Question/Answer For Fresher

noreply@blogger.com (PD Patel) — Thu, 6 Aug 2015 12:01:00 +0530

What are the assumptions made in simple theory of bending?

The assumptions made in the theory of simple bending are:

> The material of the beam is homogeneous this implies that it is uniform in density, strength and have isotropic properties meaning possessing same elastic property in all directions.

> Even after bending the cross section of the beam remains constant.

> During the initial stages the beam is straight and unstressed.

> All the stresses in the beam are within the elastic limit of its material.

> The layers of the beam are free to contract and expand longitudinally and laterally

> On any cross section the perpendicular resultant force of the beam is zero.

> Compared to the cross-sectional dimension of the beam the radius of curvature is very large.

Why is stress considered important in a shaft?

The following types of stresses are prevalent in shafts:

> At the outermost surface of the shaft the max shear stress occurs on the cross-section of the shaft.

> At the surface of the shaft on the longitudinal planes through the axis of the shaft the maximum longitudinal shear stress occurs.

> At 45 degrees to the maximum shearing stress planes at the surface of the shafts the major principal stress occurs. It equals the max shear stress on the cross section of the shaft.

> For certain materials where the tensile and compressive strengths are lower in measure as compared to the shear strength, then the shaft designing should be carried out for the lowest strengths.

> All these stresses are of significance as they play a role in governing the failure of the shaft. All theses stresses get generated simultaneously and hence should be considered for designing purposes.

What do you understand by the Hooke`s Coupling what are its purposes?

The Hooke`s coupling is used to connect two shafts whose axes intersect at a small angle. The two shafts are inclined at an angle and is constant. During motion it varies as the movement is transferred from one shaft to another. One of the major areas of application of this coupling is in gear boxes where the coupling is used to drive the rear wheels of trucks and other vehicles. In such usage scenarios two couplings are used each at the two ends of the coupling shaft. they are also used to transfer power for multiple drilling machines. The Hooke`s coupling is also known as the Universal coupling. The torque transmitted by the shafts is given by :

T= (pie/16) x t x (d) cube

Where T = torque, t = shear stress for the shaft material and d the diameter of the shaft.

What kind of materials should be used for shafts manufacturing?

Some of the qualities that should be present in materials for shafts are as follows:

> The material should have a high index of strength.

> Also it should have a high level of machinability.

> The material should possess a low notch sensitivity factor.

> The material must also have wear resistant properties.

> Good heat treatment properties should also be present

The common material used to creates shafts of high strengths an alloy of steel like nickel is used. The shafts are manufactured by hot rolling processes and then the shaft is finished using drawing or grinding processes.

Why should a chain drive be used over a belt or rope driven drive? State pro`s and con`s?

The advantages of using a chain drives are:

> In a chain drive no slip occurrence takes place.

> The chains take less space as compared to rope or belts as they are made of metal and offer much strength.

> The chain drives can be used at both short and long ranges and they offer a high level of transmission efficiency.

> Chain drives can transmit more load and power as compared to belts.

> A very high speed ratio can be maintained in one step of chain drives.

Some of the cons of using a chain drive are:

> The cost of producing chain drives is higher as compared to that of belts.

> The chain drives must be serviced and maintained at regular intervals and henceforth their cost of ownership is high comparatively.

What are the different types of springs and explain them briefly?

Springs can be broadly classified into the following types:

> Helical Springs: These springs as their name suggests are in coil form and are in the shape of helix. The primary purpose of such springs are to handle compressive and tensile loads. They can be further classified into two types: compression helical spring and tension helical spring each having their own unique areas of application./

> Conical and volute springs: Both these spring types have specialized areas of usage where springs with adaptable rate according to the load is required. In case of conical springs they are wound so as to have a uniform pitch while on the other hand volute springs are wound in a slight manner of a parabloid.

> Torsion Springs: The characteristics of such springs is that they tend to wind up by the load. They can be either helical or spiral in shape. These types of springs are used in circuit breaker mechanisms.

> Leaf springs: These types of springs are comprised of metal plates of different lengths held together with the help of bolts and clamps. Commonly seen being used as suspensions for vehicles.

> Disc Springs: As the name suggests such types of springs are comprised of conical discs held together by a bolt or tube.

> Special Purpose Springs: These springs are all together made of different materials such as air and water.

Common Mechanical Interview Question/Answer For Fresher

noreply@blogger.com (PD Patel) — Wed, 5 Aug 2015 12:35:00 +0530

What are the different types of fits, Tolerance, Clearance?

On the basis of Indian standards fits can mainly be categorized into three groups:

> Clearance Fit: These types of fits are characterized by the occurrence of a clearance between the two mating parts. The difference between the minimum size of the hole and the maximum size of the shaft is called the minimum clearance, the difference between the maximum size of the hole and the minimum size of the shaft is known as maximum clearance.

> Interference Fit: In these types of fits the size of the mating parts are predefined so that interference between them always occurs. The tolerance zone of the hole is completely below the tolerance zone of the shaft.

> Transition Fit: As the name suggests these type of fit has its mating parts sized limited to allow either clearance or interference. The tolerance zone of the hole and the shaft overlaps in case of such fits.

For a shaft designated as 40 H8/f7, calculate the tolerances.

Given: Shaft designation = 40 H8/f7

The shaft designation 40 H8/f 7 means that the basic size is 40 mm and the tolerance grade for

the hole is 8 ( i. e. I T 8) and for the shaft is 7 ( i. e. I T 7).

Since 40 mm lies in the diameter steps of 30 to 50 mm, therefore the geometric mean diameter,

D = Square root of (30 x 50) = 38.73 mm

We know that standard tolerance unit,

i = 0.45 x Cube root of (D) + 0.001 D

i = 0.45 × 3.38 + 0.03873 = 1.559 73 or 1.56 microns

i = 1.56 × 0.001 = 0.001 56 mm ...(1 micron = 0.001 mm)

The standard tolerance for the hole of grade 8 (IT8)

= 25 i = 25 × 0.001 56 = 0.039 mm

The standard tolerance for the shaft of grade 7 (IT7)

= 16 i = 16 × 0.001 56 = 0.025 mm

What are the factors that can affect the Factor of safety selection?

The factor of safety is used in designing a machine component. Prior to selecting the correct factor of safety certain points must be taken into consideration such as:

> The properties of the material used for the machine and the changes in its intrinsic properties over the time period of service.

> The accuracy and authenticity of test results to the actual machine parts.

> The applied load reliability.

> The limit of stresses (localized).

> The loss of property and life in case of failures.

> The limit of initial stresses at the time period of manufacture.

> The extent to which the assumptions can be simplified.

The factor of safety also depends on numerous other considerations such as the material, the method of manufacturing , the various types of stress, the part shapes etc.

What is heat treatment and why is it done?

Heat treatment can be defined as a combination of processes or operations in which the heating and cooling of a metal or alloy is done in order to obtain desirable characteristics without changing the compositions. Some of the motives or purpose of heat treatment are as follows:

> In order to improve the hardness of metals.

> For the softening of the metal.

> In order to improve the machinability of the metal.

> To change the grain size.

> To provide better resistance to heat, corrosion, wear etc.

Heat treatment is generally performed in the following ways:

> Normalizing

Normalizing involves heating steel, and then keeping it at that temperature for a period of time, and then cooling it in air. The resulting microstructure is a mixture of ferrite and cementite which has a higher strength and hardness, but lower ductility. Normalizing is performed on structures and structural components that will be subjected to machining, because it improves the machinability of carbon steels.

> Annealing

Annealing involves treating steel up to a high temperature, and then cooling it very slowly to room temperature, so that the resulting microstructure will possess high ductility and toughness, but low hardness. Annealing is performed by heating a component to the appropriate temperature, soaking it at that temperature, and then shutting off the furnace while the piece is in it. Steel is annealed before being processed by cold forming, to reduce the requirements of load and energy, and to enable the metal to undergo large strains without failure.

> Spheroidising

> Hardening

> Tempering

Tempering involves heating steel that has been quenched and hardened for an adequate period of time so that the metal can be equilibrated. The hardness and strength obtained depend upon the temperature at which tempering is carried out. Higher temperatures will result into high ductility, but low strength and hardness. Low tempering temperatures will produce low ductility, but high strength and hardness. In practice, appropriate tempering temperatures are selected that will produce the desired level of hardness and strength. This operation is performed on all carbon steels that have been hardened, in order to reduce their brittleness, so that they can be used effectively in desired applications.

> Surface or case hardening

What are the rules that must be kept in mind while designing castings?

Some of the points that must be kept in mind during the process of cast designing are as follows:

> To avoid the concentration of stresses sharp corners and frequent use of fillets should be avoided.

> Section thicknesses should be uniform as much as possible. For variations it must be done gradually.

> Abrupt changes in the thickness should be avoided at all costs.

> Simplicity is the key, the casting should be designed as simple as possible.

> It is difficult to create true large spaces and henceforth large flat surfaces must be avoided.

> Webs and ribs used for stiffening in castings should as minimal as possible.

> Curved shapes can be used in order to improve the stress handling of the cast.

What are the points that should be kept in mind during forging design?

Some of the points that should be followed while forging design are:

> A radial flow of grains or fibers must be achieved in the forged components.

> The forged items such as drop and press forgings should have a parting line that should divide the forging into two equal halves.

> The ribs in a forging should not be high or thin.

> In order to avoid increased die wear the pockets and recesses in forgings should be minimum.

> In forgings the parting line of it should lie as far as possible in a single plane.

> For ease of forging and easy removal of forgings the surfaces of the metal should contain sufficient drafts.

Describe briefly the different cold drawing processes.

Some of the important cold drawing processes are as follows:

> Bar and Rod Drawing: In the case of bar drawing the hot drawn bars are at first pickled, washed and coated to prevent oxidation. Once this is done a draw bench is used for the process of cold drawing. In order to make an end possible to enter a drawing die the diameter of the rod is reduced by the swaging operation. This end is fastened by chains to the draw bench and the end is gripped by the jaws of the carriage. In this method a high surface finish and accuracy dimensionally is obtained. The products of this process can be used directly without any further machining.

> Wire Drawing: Similar to the above process the bars are first pickled, washed and coated to prevent any oxidation. After this the rods are passed through several dies of decreasing diameter to provide a desired reduction in the size ( diameter ). The dies used for the reduction process is generally made up of carbide materials.

>Tube Drawing: This type of drawing is very similar to the bar drawing process and in majority of cases it is accomplished by the use of a draw bench.

What are the different theories of failure under static load, explain briefly?

The main theories of failure of a member subjected to bi-axial stress are as follows:

> Maximum principal stress theory ( Rankine’s theory): This theory states that failure occurs at a point in member where the maximum principal or normal stress in a bi-axial system reaches the maximum strength in a simple tension test.

> Maximum shear stress theory ( Guest’s or Tresca’s theory): This theory states that failure occurs when the biaxial stress reaches a value equal to the shear stress at yield point in a simple tension test.

> Maximum principal strain theory ( Saint Venant theory): This theory states that failure occurs when bi-axial stress reaches the limiting value of strain.

> Maximum strain energy theory ( Haigh’s theory): This theory states that failure occurs when strain energy per unit volume of the stress system reaches the limiting strain energy point.

> Maximum distortion energy theory ( Hencky and Von Mises theory): This theory states that failure occurs when strain energy per unit volume reaches the limiting distortion energy.