Materials Lab

7/25/2019 Materials Lab

http://slidepdf.com/reader/full/materials-lab 1/14

University of San Carlos

Technological Center

Nasipit, Talamban

QUALITY TEST !" #!T$%I&&E% 'INC$C!ATE% ()AL*ANI'E%+

L!N)ITU%INAL EL%E% STEEL &I&E !" !"%INA"Y USE

E-periment No. /

I. OBJECTIVE

0. To 1etermine an1 verify the 23ality of pipe 3sing the 1imensional test, flattening

test an1 4eight of 5inc coating test.

/. To meas3re the pipe 4ith acc3rate precision 4ith the 3se of *ernier calliper an1

micrometer calliper.

6. To 1etermine the strength of the 4el1 an1 the material 4ith the 3se of 3niversal

testing machine.

7. To 1etermine the amo3nt of 5inc coating 4ith the 3se of meas3ring instr3ments an

aci1 bath proce13re.

8. To compare the recor1e1 1ata 4ith the specification &NS /9: 0;<7 (&hilippine

National Stan1ar1+ Specifications for =lac> an1 #ot %ippe1 'inc$Coate1 &ipe Light

Series II.



II. Introduction

)alvani5e1 pipe or 5inc$coate1 pipes are 3s3ally 3se1 for 4ater 1istrib3tion

system. These are 3se1 since it is ma1e 3p of steel alloy that can 4ithstan1 certain

internal an1 e-ternal press3re 4hich is e-ists in a 4ater 1istrib3tion system. The

reason 4hy it is coate1 4ith 5inc is to protect the steel alloy from corrosion. Corrosion

of alloys can affect the strength of the material. or health an1 sanitary p3rposes, it

can affect the 4ater 23ality being 1istrib3te1.

ig. 0 )alvani5e1 pipe

&ipe varies in 4all thic>ness. In this material test, the 4all thic>ness is

classifie1 into certain criteria.

ig. / all Thic>ness (Co3rtesy 444.yo3t3be.com+

or the pipe to be 23alifie1 as thin 4alle1, the ratio of the internal ra1i3s an1

the thic>ness sho3l1 be greater than 0?.



In this e-periment, the strength of the pipe is teste1 by compressing 4ith the

3se of 3niversal testing machine. Its 5inc coating is teste1 4ith the aci1 bath test.

Stress is the force acting per 3nit area over 4hich the force is applie1. This can

ca3se 1eformities 4hich or change in 1imension 4hich is calle1 strain. In the

e-periment, the pipe 3n1ergoes compression. Compressive press3re is the press3re

acting on it or p3shing it th3s changing its form.

Stress= Force

Area E2n. 0

Strain @∆ d imension

originaldimension=

∆ Lorig.L

=∆ A

orig . A=

∆ horig.h

E2n. /

There are 1ifferent types of stresses that are relate1 4ith pipes. The first one is

the longit31inal stress. It is the stress along the a-ial 1irection of the pipe. Secon1, the

circ3mferential stress is the stress ca3se1 by the internal press3re 1irecte1 thro3gh the

inner s3rface of the pipe. Thir1, the ra1ial stress 4hich is ca3se1 by internal press3rean1 present in the pipe 4all.

Longit31inal stress is the stress along the a-is of the pipe. It is normal to the

cross$sectional area of the pipe. It co3nters the internal press3re in the pipe.

ig. 6 Internal &ress3re insi1e the &ipe



ig. 7 Longit31inal Stress in "elation 4ith the Internal &ress3re

here SL @ longit31inal stress

r i @ internal ra1i3s

r m @ mean ra1i3s

r o @ e-ternal ra1i3s

p @ internal press3re

t@ thic>ness

E2n. 6 %erivation of the E23ation for Longit31inal Stress (Co3rtesy

444.yo3t3be.com+

http://www.youtube.com/




Circ3mferential stress or the #oop stress is the stress ca3se1 by the internal

press3re 1irecte1 into the internal s3rface of the pipe. It co3nters the internal press3re

1irecte1 into the internal s3rface of the pipe. This stress occ3rs on the 4alls of the

pipe.

ig. 8 #oop Stress

ig. 9 #oop Stress in "elation 4ith Internal &ress3re

here SL @ longit31inal stress

S# @ #oop stress

r i @ internal ra1i3sr m @ mean ra1i3s




p @ internal press3re

l @ length

t@ thic>ness

E2n. 7 %erivation for the orm3la of #oop Stress (Co3rtesy

444.yo3t3be.com+

"a1ial Stress is ca3se1 by the internal press3re in the pipe. It varies bet4een

the internal press3re 1irecte1 on the internal s3rface of the pipe an1 the atmospheric

press3re 1irecte1 on the e-ternal s3rface of the pipe.

ig. "a1ial Stress in the &ipe

here S" @ ra1ial stress

r i @ internal ra1i3s

r m @ mean ra1i3s


& @ press3re

E2n. 8 orm3la for "a1ial Stress (Co3rtesy 444.yo3t3be.com+







To test the strength of the pipe, it is compresse1 4ith the 3se of the Universal

Testing Bachine. The Universal Testing Bachine is 3se1 to test the capability of the

pipe to 4ithstan1 e-ternal press3re 13ring compression.

Corrosion is the formation of r3st 13e to o-i1ation of metals. Corrosion can

affect the strength of the material. %3e to corrosion, it can 1ecrease its strength an1

the capacity to 4ithstan1 e-ternal an1 internal press3re. In ig.6, r3st is forme1. It is

characteri5e1 by yello4$orange to orange colo3r. It is 13e to the presence of iron

compo3n1.

E2n. 9

Corrosion an1 ormation of "3st

)alvani5ing is a process of coating iron or steel 4ith 5inc. Its p3rpose is to

protect the alloy from corrosion. In ig. /, it sho4e1 the process of coating the steel

pipe 4hich is hot 1ip. The steel pipe is coate1 4ith 5inc by 1ipping it in a hot mi-t3re

of 5inc.

ig. / )alvani5ation &rocess

e 6!/ /#/! @ /e/!6#/!



Thro3gh the Aci1 =ath E-periment, the amo3nt of 5inc coating on the steel

pipe can be 1etermine1. The sample is s3bmerge1 in 6D concentrate1 #y1rochloric

Aci1. The 5inc an1 the hy1rochloric aci1 react 4ith each other 4hich is evi1ent on the

formation of b3bbles an1 the release of gas. This can be sho4n in a chemical

e23ation:

E2n.

In or1er to 1etermine the amo3nt of 5inc present on the steel pipe, the e23ation

belo4 is 3se1.

E2n. <

here:

C @ 4eight of 5inc coating

t @ original 4eight, grams

f @ final 4eight, grams

A @ coate1 area of specimen, mm/

0??? @ conversion factor

The 5inc coating of the galvani5e1 pipe reacts 4ith the hy1rochloric aci1 an1

forms into 5inc chlori1e. It release1 a gas 4hich is hy1rogen. hat is left on the pipe

after the chemical reaction is the steel pipe itself consi1ering that it has no imp3rities.

In this e-periment, steel pipes are of main concern. Steel pipes are very

important most especially on 4ater 1istrib3tion. itho3t pipes, it 4o3l1 be 1iffic3lt to

provi1e 4ater to the 1ifferent comm3nity.

ater is the main reason for corrosion to occ3r. Steel pipes are al4ays

e-pose1 4ith 4ater. This is the reason 4hy it is a nee1 to cover it 4ith 5inc to prevent

it from o-i1i5ing an1 corrosion.

It is very important to cover it 4ith 5inc most especially for health p3rposes

an1 the 23ality of 4ater being 1elivere1.

'n /#Cl @ 'nCl/ #/

C =Wt −Wf

A x100



III. EQUIPMENT

0 eighing Scale

0 Tong

0 =ea>er

0 *ernier Caliper

0 Bicrometer Caliper

0 #ac>sa4

IV. MATERIALS

/ pcs Steel &ipe Specimen

0?? mL 6D #Cl Aci1



IV. PROCEDURE

A. %imensional Test

0. Chec> the *ernier calliper an1 micrometer caliper if there are any 1efects.

/. Beas3re the o3tsi1e 1iameter of the pipe in mm. Beas3re it five times. in1

the average of the meas3re1 1ata.

6. Beas3re the insi1e 1iameter 4ith *ernier calliper in mm. Beas3re it fie

times. in1 the average of the meas3re1 1ata.

7. Beas3re the average thic>ness of the pipe in mm. Use micrometer calliper.

Beas3re it five times at 1ifferent locations.

=. lattening Test

0. el1 positione1 at ? 1egree

0.0. Chec> the 3niversal testing machine if there are any problems.

0./. Assemble the compression plates on the 3niversal testing machine.

0.6. Since it re23ires lesser loa1, remove the first t4o loa1s at the bac>

of the machine.

0.7. A1F3st the 1ial an1 set it to 5ero.

0.8. T3rn on the po4er s3pply.

0.9. &lace the specimen on top of the plate.

0.. &osition it that the specimen is locate1 at the center of the plate.

0.<. or the first specimen, position it 4ith the 4el1 at 5ero 1egrees. In

other 4or1s, position it in a 4ay that the 4el1 is in contact 4ith the

plate.

0.;. T3rn on the machine by s4itching the po4er >nob.

0.0?. &ress the b3tton to start the machine.

0.00. After the start b3tton is presse1, the machine elevates slo4ly

3p4ar1s.



0.0/. ait 3ntil the top portion of the specimen be in contact 4ith the

3pper plate.

0.06. After4hich, meas3re the 1istance bet4een the t4o parallel plates

4ith a *ernier caliper.

0.07. Calc3late 8D of the recor1e1 1istance.

0.08. "ecor1 the scale.

0.09. &osition the *ernier caliper 4ith the calc3late1 val3e.

0.0. Align the gap bet4een the caliper 4ith the gra13ations fo3n1 on

the 3niversal testing machine.

0.0<. Ba>e it in the 4ay that the 5ero of yo3r *ernier Caliper is aligne1

4ith the top most pars of the scale fo3n1 on the machine. "ecor1 the

meas3rement.

0.0;. hen the elevation of the raising part of the machine, reaches to

the recor1e1 meas3rement. Stop the machine,

0./?. Chec> the specimen if there are any crac>s fo3n1 on the

specimen.

0./0. After4hich, repeat steps 0.07 0.0; b3t calc3late the recor1e1

1istance or the 1iameter by 9?D. "ecor1 the scale.

0.//. After the e-periment, remove the specimen from the machine.

!bserve any changes fo3n1 on the specimen li>e formation of crac>s.

/. el1 positione1 at ;? 1egrees

/.0. "epeat steps 0.9 $ 0.//.

/./. In this case, position the 4el1 at ;? 1egrees. &osition it in the 4ay

that the 4el1 is at the left part of the pipe.

/./ "ecor1 the 1ata an1 any observation on the changes of the pipe.

C. eight of 'inc Coating Test

0. C3t 0G - 0G each from the t4o compresse1 galvani5e1 pipe 4ith the 3se of

hac>sa4.

/. eight each sample 4ith the 3se of 4eighing scale or platform balance.

6. "ecor1 the thic>ness at the corners an1 at the center. Average the recor1e1

1ata to i1entify the thic>ness.



7. &o3r 0?? ml of #Cl aci1 in the bea>er. =e CA"EUL on 1oing this

proce13re. ear eye protection or goggles.

8. &lace the t4o pieces into the aci1.

9. Cover the bea>er 4ith rag since it can irritate yo3r eyes an1 it can pro13ce

an irritating smell.

. =3bbles are forme1 13e to the reaction of the aci1 an1 5inc. ait 3ntil the

b3bbles cease.

<. After4hich, remove the t4o pieces from flattene1 pipes.

;. "inse it 4ith 4ater an1 4ipe or 1ry it.

0?. "epeat step / to step 6.

00. "ecor1 the res3lts.

0/. Calc3late the mass of the 5inc coating 3sing the follo4ing e23ation:

C =Wt −Wf

A x100

here:

C @ 4eight of 5inc coating

t @ original 4eight, grams

f @ final 4eight, grams

A @ coate1 area of specimen, mm/

0??? @ conversion factor

V. Data and Resuts

Bechanical Engineering %epartment

Baterial Testing Laboratory

Table 0 %imensional Test

Table 0.0 Average o3tsi1e 1iameter

Sample Actual Diameter Limits Remarks (pass/fail)



A 40 mm48.6 mm - 47.8

mm

B 50 mm60.7 mm - 5.6

mm

Table 0./ Average 4all thic>ness

Sample Actual Diameter Limits Remarks (pass/fail)

A 40 mm48.6 mm - 47.8

mm

B 50 mm60.7 mm - 5.6

mm

Note: Ba-im3m val3es are not limite1 for all pipes.

The allo4able minim3m val3e for light series / is $<D.

Table / lattening Test

Specime!

"#siti#! #f $el%

&'serati#!*e! /%ista!ce is

+Di,ere!ce

Remarks(pass/fail)

60+ #f &utsi%e

Diamter

A 40 mm 0 %eree0

%ereesB 50 mm 0 %eree

0%erees

Note: &hilippine Tra1e Stan1ar1s states Hno opening shall occ3r by fract3re in the

4el1 3ntil the 1istance bet4een the plates is 8D of the original o3tsi1e 1iameter of

the pipe an1 no crac>s or brea>s in the metal else4here than in the 4el1 shall occc3r

3ntil the 1istance in the plates is 9?D of the original !.%.

VI. Standards



0. The 1imensions an1 mass of pipes shall be in accor1ance 4ith Tables 0, /, 6

an1 7.

/. The limits for o3tsi1e 1iameter of pipes shall be in accor1ance 4ith Table 8.

6. The tolerance for the thic>ness of the pipe shall be as follo4s:

6.0. Ba-im3m val3es are not limite1 for pipes.

6./. 0/.8D for heavy series, me1i3m series an1 light series 0.

6.6. <D for light series /.

Documents

Materials Lab