Personal Protective Equipment 500

8/7/2019 Personal Protective Equipment 500

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2011

SHIVENDRA PRATAP SINGH

SGIL

5/2/2011

PERSONAL PROTECTIVE

EQUIPMENTS,WELDING,NDT&PWHT


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Personal protective equipment

Supervisers are responsible to ensure personal

protectiveequipment is worn to protect

workers from potential hazards

MORE THAN ONE-FOURTH OF THESE INJURIES

WILL INVOLVE THE HEAD, EYES, HANDS, OR

FEET

Clothing that protects the body & extremities

will be worn

Loose clothing will not be worn where it can

contact or catch on energised conductors


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,moving parts,equipment,or other hazards of

this type

UNDER THE REQUIREMENTS OF 29 CFR

1910.132, ENGINEERING CONTROLS SHALL BETHE PRIMARY METHOD USED TO ELIMINATE

HAZARD EXPOSURE IN THE WORK PLACE.

TYPES OF EYE AND FACE PROTECTION

INCLUDE:

-SAFETY GLASSES

- GOGGLES

- FACE SHIELDS


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- WELDING HELMETS

HEAD PROTECTION:

l HELMETS AND HATS FOR THE PROTECTION OF

DOC EMPLOYEES FROM THE IMPACT OF

FALLING AND FLYING OBJECTS AND FROM

LIMITED ELECTRICAL SHOCK AND BURN SHALL

MEET THE SPECIFICATIONS OF ANSI Z89.1

HEAD PROTECTION

SHELL IS DESIGNED TO ABSORB SOME IMPACT

SUSPENSION MUST BE ADJUSTED SO SHELL IS

1.5 INCHES ABOVE THE HEAD


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HARD HATS ARE TESTED TO WITHSTAND

IMPACT OF 8 LB WEIGHT DROPPED FROM 5 FT

HARD HATS MUST ALSO MEET WEIGHT,

FLAMMABILITY AND ELECTRICAL INSULATION

STANDARDS

(HARD HAT)

FOOT PROTECTION

l FOOT INJURIES ARE MOST LIKELY TO OCCURWITH:

HEAVY OBJECTS FALLING ON YOUR FEET

ROLLING OF HEAVY OBJECTS

PIERCING OF OBJECTS THROUGH SOLES OF

YOUR SHOE

FEW POINTS REMEMBERED FOR

PREVENTING FOOT INJURIES


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IF WORKING AROUND ELECTRICAL WIRES,

BOOTS/SHOES MUST BE METAL FREE AND

NON-CONDUCTIVE

STATIC FREE ENVIRONMENTS REQUIRE

CONDUCTIVE SHOES

RUBBER OR SYNTHETIC FOOTWEAR MAY BE

REQUIRED AROUND CHEMICALS

AVOID LEATHER SHOES/BOOTS AROUND

CORROSIVES

FOOT GUARDS AND HEEL AND ANKLE

SHIELDS MAY BE REQUIRED FOR

PARTICULAR WORK

(SAFETY BOOTS)

HAND PROTECTION


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FINGERS, HANDS AND ARMS ARE INJURED

MORE THAN OTHER PARTS OF THE BODY

GLOVES ARE THE MOST COMMON PROTECTORS

FOR THE HANDS

BARRIER CREMES MAY BE USED AS HAND

PROTECTION OR, IN CONJUCTION WITH OTHER

HAND PROTECTION

HAND GLOVES (RUBBER)

HEARING PROTECTIONREQUIRED WHEN NOISE MEETS OR EXCEEDS

85DBA.IF YOU HAVE TO YELL TO BE HEARD

,WEAR EARPLUGS

(EAR PLUGS)


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SAFETY GLASSES-

To be worn at all times when in constructional

area.Additional eye/face protection should be

wornwhen theres a possibility of flying debrisfor work being performed by either the

employee or others in the area-

Working with crushing equipment

Hammering,chipping,drilling

Cutting with disc or power-driven saw andother cutting under tension

Any grinding work

Use of compressed air ,water or other

liquid/solutions with shot,injection or

other abrasive cleaning

Use and handling cartridge-operated tools.

Working with chemical solid-liquid

substances

Concrete(spraying&vibration) pouring.

Coiling rebar/cable and related

operations,such as cable straightening. Strapping and unstrapping under tension.

Handling of glass either whole or broken.


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Approved dark/tinted safety glasses should be worn when

working in the bright sunlight.However ,clear glasses

should be worn at night and when inside buildings or in

covered areas with limited lightingsPerforming abrasive

blasting work.

Face shields-

Face shields must be worn in addition to safety

glasses when

performing,cutting,grinding,hammering,chippi

ng,handling hazardous liquids,abrasive

blasting,cartridge operated tools and concrete

work.


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Welding

a localized coalescence of metals or non metals

produced either-

By heating the materials to the welding

temperature ,with or without the application of

pressure or

By the application of pressure alone and with

or without the use of filler metal.


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Common welding process

Shielded metal arc welding(SMAW)

Gas tungsten arc welding(GTAW)

Gas metal arc welding(GMAW)

Flux cored arc welding(FCAW)

Submerged arc welding(SAW)

GMAW PROCESS

Popularly known as MIG process.


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It is a semi-automatic process.

Uses gases(co2,argon or mix)for

shielding.

Uses continuous solid metal wire

feed.

No deposition of slag.

High productivity 3kg/hr or more

GMAW EQUIPMENTS


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Welding power source

Wire feeder mechanism

Gun with gas supply & trigger switch

-manual(semi automatic)guns

-automatic torches available

Flux core arc welding

Similar to GMAW process except that the

electrode is tubular containing a granular

flux.


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Shielding gas may or may not be used

depending on the type of electrode

used(eg. Self-shielded flux cored wires do

not require gas shielding).

Solidified weld metal is covered by a layer

of slag.

Equipment used is identical to gmaw

except high current capacity guns and

power sources.

Equipment set upFCAW

Torch

Electric power source

Shielded gas source

Wire spool with wire drive control


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Torch gas mixture

Inert gas (MIG)

-Argon or helium or mixture of these

Active gases(MAG&FCAW)

-Carbon dioxide

-argon plus oxygen and/or carbon dioxide

-nitrogen,hydrogen

ELECTRODE/ROD CLASSIFICATION AS PER

AWS

EXXT-X

WHERE-

E-electrode rod

X-minimum tensile strength in ten thousand

psi

X-position (0- F&H,1-ALL Positions)

T-tubular electrode

X-chemical composition/operati

characterstics


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ADVANTAGES-

High efficiency due to increased deposition

rate. Good performance on contaminated surfaces.

Baking process of electrodes eliminated.

Can be used for field applications.

Deep penetrating arc reduces the possibility of

fusion problems.

Frequent changing of electrode is eliminated.

Metal conversion factor is upto 95%.

LIMITATION-

Presence of a layer of solidified slag

Smoke generated is more than in

GMAW&SMAW.

Equipment required is more complex.

Slag inclusion due to trapping slag within

the weld deposit.

Not advisable for pipe thickness less than

12.5mm.

Requires proper wind shielding.

High travel speed is required.


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SMAW FCAW

-Slower process -faster process

-example- -for the

same joint

For a 30*12.7mm joint, it takes

only 1.5hrs

It takes 4.5hrs

-for a weldolet of 16*10 -for the

same weld it

It takes 7 hrs takes only

2.15 hours

FCAW IS THREE(3) TIMES FASTER THAN SMAW

Welding position


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WELD FINISH

BUTT WELD-

(BUTT WELD)


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Butt welding is a metalwelding process in which round or profilestock is welded end to end.

Butt welding can be used to run a processing machine continuously,as opposed to having to restart such machine with a new supply ofmetals.

Usually, the seams (or abutment sections) are cleaned andprepared, and set on an automated piece of equipment which then

welds the two materials together.Afterward, the material isusually ground down to a smooth finish and either sent on its wayto the processing machine, or sold as a completed product.

WELD FINISH-WELDOLET
http://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Weldinghttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Welding


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Weldolet are basically self reinforced fittings.

Weldolet is used for Butt weld branch connection where standard tee

is not

available due to size restrictions and the piping is of critical / high

pressure service.

Weld finish-trunion


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Weld finish-branch with RF pad


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MACHINES USED AT PFS-


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Lincoln make DC600 power source with LN25

wire feeder and magnum 200/400amps welding

torches.

Fronius make synergic 5000cc with VR400S

wire feeder and torch assembly.

1.2mm flux cored wire is used in both wire

feeders for better control of weld metal.

Piped CO2 gas facility available in all four

shops.

LIMITATIONS AT SITE WELDING-

Additional protection for shielding gas from

heavy windows.

Transportation of additional CO2 cylinders.

Scaffolding arrangement for wire feeder at

elevations.

Not suitable for thickness less than 12.7mm

and pipe size less than 10 inch dia.

Spacing of joint with adjacent pipe at rack.


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FUNDAMENTALS OF NDT


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Nondestructive testing (NDT) is a wide group of

analysis techniques used in science and industryto evaluate the properties of a material,component or system without causing damage.The terms Nondestructive examination (NDE),Nondestructive inspection (NDI), andNondestructive evaluation (NDE) are alsocommonly used to describe this technology.Because NDT does not permanently alter thearticle being inspected, it is a highly-valuabletechnique that can save both money and time inproduct evaluation, troubleshooting, and research.Common NDT methods include ultrasonic,magnetic-particle, liquid penetrant, radiographic,remote visual inspection (RVI), eddy-currenttesting, andlow coherence interferometry. NDT isa commonly-used tool in forensic engineering,mechanical engineering, electrical engineering,

civil engineering, systems engineering,aeronautical engineering, medicine, andart.

S cope-

NDT method are used to detectsurface,subsurfaces and internaldiscontinuities in the materials and give

quality control checks in various stages ofmanufacturing

ASME sec-V IS the relevant code for thevariouss NDT methods used in industries.

PROGRAM OBJECTIVE -
http://en.wikipedia.org/wiki/Ultrasonic_testinghttp://en.wikipedia.org/wiki/Magnetic-particle_inspectionhttp://en.wikipedia.org/wiki/Liquid_penetrant_testinghttp://en.wikipedia.org/wiki/Radiographic_testinghttp://en.wikipedia.org/wiki/Eddy-current_testinghttp://en.wikipedia.org/wiki/Eddy-current_testinghttp://en.wikipedia.org/wiki/Optical_interferometryhttp://en.wikipedia.org/wiki/Forensic_engineeringhttp://en.wikipedia.org/wiki/Mechanical_engineeringhttp://en.wikipedia.org/wiki/Electrical_engineeringhttp://en.wikipedia.org/wiki/Civil_engineeringhttp://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/Aeronautical_engineeringhttp://en.wikipedia.org/wiki/Medicinehttp://en.wikipedia.org/wiki/Arthttp://en.wikipedia.org/wiki/Ultrasonic_testinghttp://en.wikipedia.org/wiki/Magnetic-particle_inspectionhttp://en.wikipedia.org/wiki/Liquid_penetrant_testinghttp://en.wikipedia.org/wiki/Radiographic_testinghttp://en.wikipedia.org/wiki/Eddy-current_testinghttp://en.wikipedia.org/wiki/Eddy-current_testinghttp://en.wikipedia.org/wiki/Optical_interferometryhttp://en.wikipedia.org/wiki/Forensic_engineeringhttp://en.wikipedia.org/wiki/Mechanical_engineeringhttp://en.wikipedia.org/wiki/Electrical_engineeringhttp://en.wikipedia.org/wiki/Civil_engineeringhttp://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/Aeronautical_engineeringhttp://en.wikipedia.org/wiki/Medicinehttp://en.wikipedia.org/wiki/Art


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To bring the awareness of various NDTmethods ,their applications ,advantages andlimitations.

To share our field experience and discuss case

studies to high light the importance of NDT.

BRIEF DESCRIPTION OF NDT -

Various NDT methods are used in theindustries for the various purpose at different

stages. The mechanism of each method varies and is

based on the scientific principles,they arebased on the application of sound energy,electrical energy,mechanical energy,magneticenergy etc.photo graphic principle of lightenergy is also used.

Each method has its own advantage and

limitation. They are used in various fields like medical

field ,ENGG. INDUSTRIES and also in day to daylife.

Sonography is used to check the sex of unbornchild.

X-ray are use in the airport to check theluggage of the passenger.

MT,UT&PT ARE USED IN INDUSTRIES.

APPLICATION-

DEFECT DETECTION-type,size&location ofdefects


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CHECKING OF VARIOUS PROPERTIES-density,chemical composition,electrical andthermal conductivity.

Sorting out mix up of material-composition,grain size,chemicalcomposition&heat treatment cond.

DIMENSIONAL GAUGING-materialthickness&coating/plating thickness check.

IN SGIL we use NDT methods mostly for defectdetection and thickness checking of thepipes,plates,forgings castings and welding.

SELECTION OF NDT METHOD

Selection of NDT method to check the quality ofproduct is based on the following information-

Type & location of the defect.

Nature of the defect.

Expected orientation of the defect.

Surface condition.

Applicable codes&standards.(ASME,BS,IS,DINetc.)

Quantity of materials and facilities of NDTmethod.

Inspection at site or at workshop. Accessibility for the site inspection.

Environmental condition.

NDT instrumental availability.

Cost&time reqd.


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VISUAL TESTING -

Visual testing is the oldest and simple NDTmethod and most commonly used

everywhere.it is used to detect surface defectslike laps,cracks,blow holes and many otherdefects which are visible to nakedeyes.nowadays sophisticated instruments likeboroscope,fibroscope,magnifying lensesetc,are used.

REQUIREMENT FOR TESTING -

Natural light/light source

Safe scaffolding

Personal safety equipments

Surface temperature with in 10 to 300c The surface for visual testing shall be free from

loose scale,paint and discontinuities such as pitsor gauges,weld spatter,dirt or other foreignmatter which affect examination results.

MAGNETIC PARTICLE TESTING -

The magnetism is induced in the part byelectricity or by using permanent magnetresulting the flow of lines of magnetic fluxin the part.

The magnetic lines of forces which pas

through the component are breaking dueto discontinuity in the material.

These broken lines are checked by usingiron powder forming the defectbindicationson the surface at the area wherediscontinuities are present.


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MT is applicable to ferromagnetic materialonly.

It is applicable for the detection ofsurfaces and sub surface discontinuitiesonly.

MAGNETIC PARTICLE TEST-

MAGNETIC PARTICLE TEST KIT WITH MAGNETIC FIELD INDICATOR

MAGNETIC PARTICLE TESTING-


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ABOVE FIGURE MENTIONED MAGNETIC PARTICLE TESTING

LIQUID PENETRANT TESTING-

PROCEDURE-

Clean the surface area to be tested.

Apply penetrant by brushing or spraying;wait for 7 to15 mins.

Remove excess penetrant by wiping with lint free

cloth.

Apply developer &wait for 15 minutes

Inspection and evaluation of the defects.

Cleaning to be done with free cloth only.

LIMITATION-


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Surface temperature with in 10 to 52c.

Smooth surface is required.

Porous material can not be tested.

REQUIREMENT FOR TESTING-

Natural light/light source.

Safe scaffolding.

Personal safety equipments.

Surface temperature with in 10 to 52c.

The surface for liquid penetrant testing shall be free from

loose scale ,paint and discontinuities such as pits or

gouges,weld spatter,dirt or other foreign matter which

affect examination results.

The surface preparation can be carried out by grinding.

The purpose of surface preparation is-

-to avoid masking indication on te job surface

-to remove excess penetrant by wiping facilitate on

job surface

figure mentioned liquid penetrant testing.


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THE FIGURE MENTIONED BELOW IS LIQUID

PENETRATION TESTING KIT WITH

CLEANER,PENETRANT&DEVELOPER-

ULTRA SONIC TESTING-

Ultrasonic sound waves are generated by using

electrical transducer.these waves are transmitted in thematerial by using couplant.the sound waves are flowing

inside the material and are distributed by the presence

of discontinuities in the material.The path of sound

waves and its disturbance is monitored on the CRT

screen.the loss of sound energy is indicated on the

screen which gives the idea about the defects ,its

size&location.

REQUIREMENT

NATURAL LIGHT/LIGHT SOURCE

SAFE SCAFFOLDING

PERSONAL SAFETY EQUIPMENTS


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SURFACE TEMP. WITH 10 TO 52C

SURFACE FOR UT SHALL BE UNIFORM AND FREE

FROM LOOSE SCALE,PAINT AND AND

DISCONTINUITIES SUCH AS PITS,WELDSPATTER,DIRT OR OTHER FOREIGN MATTER WHICH

AFFECT EXAMINATION RESULTS

SURFACE PREPARATION CAN BE CARRIED OUT BY

GRINDING.

PURPOSE OF SURFACE PREPARATION-

-TO HAVE BETTER CONTACT AND TO FACILITATE

BETTER CONTACT OF

PROBE ON JOB SURFACE

SURFACE PREPARATION FOR

TESTING-

DIFFERENT TYPES OF SURFACE PREPARATIONS

ARE REQUIRED FOR PIPING

,NOZZLE&STRUCTURAL JOBS AS UNDER.

PIPE TO PIPE JOINT.

IN THIS TYPE OF JOINT,SURFACE TO BE

PREPARED FOR LONGITUDINAL SCANNING ON

THE PIPE SURFACE.TE SCANNING ZONE OR

SKIP DISTANCE REQUIRED IS 250MM ON BOTH

SIDES OF THE JOINT.SCANNING ZONE SHALL BE

FREE FROM WELD SPATTER,CLEAT MARK ETC.

ALSO SURFACE NEEDS TO BE PREPARED FOR

CIRCUMFERENTIAL SCANNING.HERE SCANNING

IS CARRIED OUT FROM TOP OF THE JOINT.SO

RIPPLES OF THE WELD JOINT SHALL BE


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GROUND FLAT TO HAVE A PROPER SEATING OF

THE MINIATURE PROBE MOUNTED ON SHOE ON

THE WELD JOINT.AFTER GRINDING,THE

GRINDING MARKS SHALL BE SMOOTHEN BY

LIGHT FILLING WITH ROUND FILE.

ULTRA SONIC TESTING


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ULTRASONIC TESTING TRANSDUCER


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(PHASED ARRAY ULTRASONIC TESTING)

TOFD CONFIGURATION-

RADIOGRAPHY TESTING-

Radiography testing depends upon the ability of x-rays or

gamma rays to penetrate the test material.during

penetration the rays are partially absorbed by the

material.The amount of absorption depends upon the

density and thickness of the material.Defective areas do

not absorb the radiation energy.

Difference in radiation energy due to the presence of

discontinuity is recorded on a photographic film.

REQUIREMENT OF TESTING-

Safe scaffolding.


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Safe work permit.

Surface temp. with in 10to52c

Thickness and diameter

Material

The surface for testing shall be free from loose scale

and ,discontinuous such as pits or gouges,weld

spatter,other foreign matter which affect examination

results.

The surface preparation can be carried out by

grinding.the purpose of the surface preparation is toavoid masking indication.

RADIOGRAPHY TESTING INSTRUMENT

LEAK TESTING-

The ability to find out the leakages using air/gas

medium at pressure or at vaccum.

The air or gas is filled in the vessel/tank at the

required pressure and temperature.the leakage

is detected by the loss of pressure checked by

pressure gauge.

Some times soaps solution is also used which

forms air bubbles at the area of leakage.


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The surface for testing shall be free from loose

scale,paint and discontinuities such as pits or

gouges,weld spatter,dirt or other foreign matter

which affect examination results.

The surface preparation can be carried out by

grinding

EDDY CURRENT TESTING

This method is used for various applications such

as mixed metal sorting,dimensions

gauging,detection of defect ,measuring electrical

conductivity etc.

Principle of eddy currents is based on the

generation of induced current in the material and

monitoring on the screen.


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PWHT

PROGRAM OBJECTIVE-

To refresh and update latest developments on

the post weld heat treatment(PWHT) &hydrotesting for engineers joining from other areas.

To identify the role and responsibilities of

concerned discipline engineers while handling

the PWHT ,heat treatment&hydrotesting process.


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Program contents-

Fundamentals,process and monitoring of-

Preheat

Post heating

PWHT

Hydro testing

Purpose-

Purpose of this procedure is to define the equipmentsand methods to be followed for the preheat,postheat

&PWHT.

PWHT is carried out based on

Material composition

Thickness of weldment

Process requirement

PRE HEATING AND POST HEATING ARE CARRIED OUT

TO REDUCE COOLING RATES OF DEPOSITED WELD

METAL &HAZ FROM FUSION TEMPERATURE

TO REMOVE MOISTURE PRIOR TO START OF

WELDING WHICH PRODUCES HYDROGEN IN

PRESENCE OF ELECTRIC ARC.

REQUIREMENT OF PRE&POST HEATING-

For preheating,the weld joint shall be preheated

at or above the min. temperature in all direction


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from the point of welding for a distance of 3 or

1.5 times base metal thickness.

In case of welding of two different p no.

materials,the min. preheat temperature shall behigher temperature for the materials to be

welded

When welding two different thickness,oreheat

temperature shall be the higher temperature for

the material to be welded

When welding two different thickness,preheat

temperature shall be the greater of the nominalthickness at the weld.

Preheating shall cover all types of welds

including permanent welds,tack welds,temporary

attachments,repair welds,seal welds of threaded

joints as applicable.

METHODS OF PRE-HEATING-

For CS/LTCS ,preheating may be carried out by

flame heating or electrical heating.

For low alloy steel ,piping materials above 2NB

pre heating shall be carried out by electrical

heating only.

PREHEATING IN CASE OF

INTERRUPTION IN WELDING


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After welding is commenced,preheat shall be

maintained till PWHT is performed on P number

3,4,5a,5b&6 except all the following conditions are

satisfied-

At least 9.5mkm thickness of welding is

deposited or 25% groove is filled.

For p-3,4,5A(cr3%)&P-6,the weld is subjected to an

adequate intermediate heat treatment with a

controlled rate of cooling

After cooling &before welding is resumed ,visual

examination of the weld is performed to assure

that no crack have developed

Preheat to be applied,before welding resumes.

POST HEATING-

For low alloy steels,post heating shall be carried

out a temperature specified in applicable WPS

For elec. Heating,same arrangements are

specified in PWHT shall be followed.

The method of post heating shall be as follows

-for joints 2 and below size,post heating time shall be 10 min. forother cases post heating time shall be 30minutes

-for low alloy steel material post heating shall be carried out by electric

heating for joints above2

-preheat temperature shall be continuously maintained till start of

PWHT wherever specified in the codes/specifications.

METHODS OF PWHT-


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Furnace heat treatment-for fabricated

equipments,piping&spools in mass.

Local heat treatment-for local joint of piping spool.

Flexible ceramic pads/induction coil

Combustion burner-gas fired-for fabrication

equipments

SURFACE PREPARATION-

The area to be covered for preheat ,post heat and PWHT

shall be free from paint,grease,tacks,spatters to avoid

damage due to short circuiting.

JOB KNOWLEDGR OF OPERATOR-

PWHT technician shall be capable of executing the

activity.this shall be assessed by QMD REPRESENTATIVE

PWHT(POST WELD HEAT TREATMENT)-

THIS IS THE PROCESS OF GRADUALLY AND UNIFORMLY

RAISING THE TEMPERATURE OF THE WELDMEENT AND BASE

METAL UP TO A CERTAIN TEMPERATURE ,HOLDING

SUFFICIENT TIME AT THAT TEMPERATURE AND THEN

GRADUALLY AND UNIFORMLY COOLING IT TO ROOM

TEMPERATURE.

POST WELD HEAT TREATMENT IS REQUIRED TO BE CARRIED

OUT ON WELDMENT,AS AND WHEN CALLED FOR BY

CODES/STANDARD/SPECIFICATION.THE PURPOSE OF PWHT

MAY BE EITHER OR ALONG THE FOLLOWING REASONS-

TO DISTRIBUTE THE AMOUNT OF RESIDUAL THERMAL

STRESSES PRODUCED DURING WELDING.

TO INCREASE RESISTANCE TO STRESS CORROSION.


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TO IMPROVE DIMENSIONAL STABILITY AND DUCTILITY.

TO TEMPER THE HARD MATENSITIES AS AND WHEN FORM

DURINGWELDING.

PWHT TEMPERATURE-

For heating and cooling rate,the requirement

of WPS shall be strictly followed.

Soaking/holding time &temperature-for PWHT

soaking time&temperature requirement of

WPS shall be strictly followed.

Equipment for PWHT

Control panels

Heating elements

Thermocouple

Compensating leads

Temperature recorder

Thermal insulation

Attachment unit

Earthing cable

CERTIFICATION OF CONTROL

PANELS- All equipments are purpose built.

Electric power sources are 440v,3phase primary

supply or 220v single phase with either single

phase secondary output or step down


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transformer secondary output giving low voltage

circuits.

Temperature control equipment is either

manually operated through energy regulators or

automated

All control panels are duly certified by P&M

before utilization in job to meet the requirement

as above and as per standards.

Heating elements-

Wherever induction heating is followed for

PWHT,the heating element shall be Ni-chrome

wire covered with ceramic beads/heating

pads/flexible ceramic pads.

Heating element position-

Welds shall have a circumferential band of

heating coil around the entire component

with the weld located in center.

Heating elements shall be fixed on

weldments by means of black annealed

iron wire.

The width of the heating band shall be as

follows,

For girth welds,the width of the heating

band shall be at least three times the wall

thickness at the weld of the thickest part

being joined and shall be maintained on

either side of the joint.

For nozzle and attachment welds,the

width of the band shall extend beyond the


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nozzle weld or attachment weld on each

side at least two times the header

thickness and shall extend completely

around the header.

(ABOVE IMAGE SHOWING PWHT

PROCESSES)


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THERMOCOUPLES-

Material shall be the ktype i.e. Nickel Chromium

/Nickel-Aluminium type

Compensating coil&thermocouple shall be caliberated

together.

The distance between two T C wires shall be min

6mm.

Insulation shall be removed from the end of the TC

WIRE shall not be more than 15mm.

Connect the positive/negative side of the TC with

respective positive/negative side of compensation

cable.

Thermocouple attachment shall be attached to the

work piece by direct wire capacity discharge method

or by nut and bolt connection.

If the nut and bolt connection method Is used,the

materials of nut-bolt shall be of compatible

composition with parent metal.


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capacity discharge method

tack welds

Number of thermocouples-

1. Minimum no. of thermocouple is one one per

heating coil.However in addition to that the

following min. no. of thermocouples shall be used

for pipe welds.


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2. Minimum requirement for number and location of

thermocouples are-

1 no. upto and inclusive of 6NPS

For 2and below,wherever joints are there within

the range of 100mm distance,one thermocouple

is permitted

2 numbers at 180degree for above 6 and up to

12 NPS inclusive.

3 numbers at 120degree for above 12NPS

For socket welds,I T C with in 100MM betweentwo joints.

But in all case minimum two layers of insulation with

minimum thickness of 50mm shall be used.open ends

to pipe and fittings shall be blanked to avoid through

draught cooling during cycle.

Verification-

For PWHT,after fixing the heating coils and the

thermocouples with proper connections with

recorder,the arrangement shall be certified by the

authorized representative of REAL QMD who shall

sign on the graph to indicate that the arrangement

are certified.Then the insulation shall be applied on

the heating coils.Again after attaining 300degree

Celsius during heating,the graph shall be recertified

by REAL QMD representatives.This requirement

shall be treated as mandatory for the acceptance of

post heating as well as for PWHT CYCLE except for

nitrogen purged/digital recorder.

During PWHT cycle front door of recorder shall be

kept in closed condition


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Interrupted PWHT-

Due to power loss,equipment failure &due to

weather condition/permit problem,there may be

an interruption in heat treatment cycle-

If interruption occurs during heating

period,the cycle can be continued from the

fallen temperature.

If interruption occurs during soaking

period ,then the soaking temperature shall

be re-estabilished from the fallen

temperature at a rate no greater than thatspecified in code/estabilished welding

procedure and the soaking cycle shall be

repeated.

If interruption occur during cooling period

where controlled cooling is required,then

the complete PWHT cycle shall be repeated.

LOCATION OFTHERMOCOUPLES-

Thermocouples shall be fixed within the

area of heating band.Additional

thermocouples may be fixed as per

requirement to confirm hot zone or

gradient limitations,if necessary.

Thermocouple and their position shall

be identified on the relevant

temperature recording chart by number

or color/symbol of stamp.


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Thermocouples requirement for branch

connection and pad shall be in line with

the requirement as mentioned in above

Thermocouples tack welded with pipeshall be removed completely after

PWHT and area to be DP tested

CALIBERATION OF

TEMPERATURE RECORDERS-

It shall be of the potentiometer ,

self compensating type havingchart feed recording.

Recorders shall be caliberated in

every 6months and caliberation

stickers shall be affixed to the

recorders

In addition, recorders shall be re-

caliberated after every repair andalso for the cases where there is

reason to believe that they are in

error.

And also to be verified for chart

speed is set to appropriate

speed,temperature recording

system is recording all

thermocouples and providinginformation on temperature

differences and trends during the

heating/cooling cycle


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Caliberation certificates shall be

available at site.

THERMAL INSULATION-

The insulation shall be extended to a

minimum distance of 3 times the

heating bandwidth.The no. of layers and

extent of insulated area depends on-

1. Wall thickness

2. Pipe or fitting diameter

3. Gradient requirements&

4. Site condition

RECORDS-

Prior to starting the electrical

heating,the following information shallbe hand written on the recorder chart

by the technician.Date ,ISO

Nos,Agencys Name,Weld joint

details&Chart no.-the chart shall be

identified with ZXXX XXX /XXXX XXX

Z indicates JERP

1st

3 digits indicate unit no. innumeric

2nd3 digits alphabetic for the name

of immediate contractor.


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3rd four digits indicate name of the

sub contractor

4th four digits indicates sequential

numbering of the chart e.g.Z312 RCC /HRIS 0001

Record of PWHT shall be

maintained in the format

2 QM 00 FMT ME 138

CHECKLIST FOR THE

STRESS RELIEVING UNIT- Check for the condition of power

cable

Check for the proper size of the

cable

Check for glanding for all cables

Check for lugging for all cables

Check for tightness for all

connection

Check for sealing of all un used

entry


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Personal Protective Equipment 500

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Transcript of Personal Protective Equipment 500