IS 3196-3: Welded low carbon steel gas cylinder exceeding 5 litre water capacity for low pressure liquefiable gases, Part 3: Methods of test

2012·1.6 MB·English

by  Bureau of Indian Standards

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IS 3196-3 (2012): Welded low carbon steel gas cylinder
exceeding 5 litre water capacity for low pressure
liquefiable gases, Part 3: Methods of test [MED 16: Gas
Cylinders]
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“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
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IS 3196 (Part 3) : 2012
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Indian Standard
WELDED LOW CARBON STEEL CYLINDERS
EXCEEDING 5 LITRE WATER CAPACITY FOR LOW
PRESSURE LIQUEFIABLE GASES
PART 3 METHODS OF TEST
( Fifth Revision )
ICS 23.060.40; 75.160.30
© BIS 2012
B U R E A U O F I N D I A N S T A N D A R D S
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

May 2012 Price Group 7
Gas Cylinders Sectional Committee, MED 16
FOREWORD
This Indian Standard (Part 3) (Fifth Revision) was adopted by the Bureau of Indian Standards, after the draft
finalized by the Gas Cylinders Sectional Committee had been approved by the Mechanical Engineering Division
Council.
This standard was first published in 1965 and subsequently revised in 1968, 1974, 1982 and 1991. This standard
is published in four parts. Other parts in this series are:
Part 1 Cylinders for liquefied petroleum gases (LPG)
Part 2 Cylinders for liquefiable non-toxic gases other than LPG
Part 4 Cylinders for toxic and corrosive gases
In the formulation of this standard considerable assistance has been taken from ISO 2291 : 2004 ‘Gas cylinders —
Transportable refillable welded steel cylinders for liquefied petroleum gas (LPG) — Design and construction’.
In this revision all the amendments have been included. This revision incorporates the following major changes:
a) Macro-examination (see 5.5).
b) A new clause on Fatigue/Cycle test has been added.
c) Results (see 5.7).
d) Failure in burst test (see 9.2).
Manufacture, possession and use of any gas, when contained in cylinders of more than 500 ml water capacity in
a compressed or liquefied state, are regulated under the Gas Cylinder Rules, 2004, of the Government of India.
This standard has been formulated in consultation and agreement with the statutory authorities under those rules.
The composition of the Committee responsible for formulation of this standard is given in Annex B.
For the purpose of deciding whether a particular requirement of this standard is complied with, the final value,
observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS2:1960
‘Rules for rounding off numerical values (revised)’. The number of significant places retained in the rounded off
value should be the same as that of the specified value in this standard.
IS 3196 (Part 3) : 2012
Indian Standard
WELDED LOW CARBON STEEL CYLINDERS
EXCEEDING 5 LITRE WATER CAPACITY FOR LOW
PRESSURE LIQUEFIABLE GASES
PART 3 METHODS OF TEST
( Fifth Revision )
1 SCOPE one cylinder shall be selected at random for these tests.
The following test specimen shall be prepared from
This standard lays down methods of test for welded
this cylinder as shown in Fig. 1.
low carbon steel cylinders intended for storage and
transportation of low pressure liquefiable gases, of a) Test specimen for parent metal (P) tensile
nominal water capacity exceeding 5 litre and up to testing:
and including 250 litre nominal water capacity. This 1) For two-piece cylinders, one tensile test
standard also lays down various tests carried out in specimen in the longitudinal direction
the plant and laboratory and details of carrying out and one tensile test specimen in the
these tests. transverse direction shall be cut from the
cylindrical portion of the cylinder.
2 REFERENCES
Alternatively, if sufficient cylindrical
The standards listed in Annex A contain provisions, length is not available to permit cutting
which through reference in this text, constitute the cylindrical portion, then one tensile
provisions of this standard. At the time of publication, test specimen may be taken from the
the editions indicted were valid. All standards are dished end (see Fig. 1A).
subject to revision and parties to agreements based on 2) For three-piece cylinders, one tensile test
this standard are encouraged to investigate the specimen in the longitudinal direction
possibility of applying the most recent editions of the and one tensile test specimen in the
standards indicated in Annex A. transverse direction from the cylindrical
portion and one tensile test specimen
3 TERMINOLOGY
from one of the dished ends may be taken
For the purpose of this standard, the definitions given (see Fig. 1B).
in IS 7241 shall apply. b) Test specimens from welds (W):
1) For two-piece cylinders, one tensile test,
4 TESTS
one root bend test and one face bend test
The details of the following tests specified in IS 3196 specimen may be taken across the
(Part 1), IS 3196 (Part 2), IS 3196 (Part 4) and IS 13258 circumferential weld (see Fig. 1A).
have been stipulated in this standard: 2) For three-piece cylinders, one tensile test,
one root bend test and one face bend test
a) Acceptance tests;
specimen may be taken across the
b) Burst and volumetric expansion test;
longitudinal weld. In addition one tensile
c) Hydrostatic stretch test; test, one root bend test and one face bend
d) Hydrostatic test; test specimen may be taken across one
e) Pneumatic leakage test; of the circumferential weld (see Fig. 1B).
f) Radiographic examination; and The specimen shall be taken alternately
from the top and bottom circumferential
g) Fatigue test/cycle test.
welds on successive cylinders selected for
5 ACCEPTANCE TESTS the test.
c) Test specimen for minimum thickness test
5.1 Number of Test Specimen
from knuckle radius portion for both two-piece
For every batch of 202 or less heat-treated cylinde rs, and three-piece cylinders.
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IS 3196 (Part 3) : 2012
d) Sample for macro-examination: thickness of a test specimen, the two faces of which
1) For macro-examination in case of two-piece are formed by the surface of the cylinder wall, differ
cylinders one specimen across circum- from one another, the minimum thickness of the test
ferential seam and one from bung weld. specimen shall be taken for calculation of the area.
The test specimen may be carefully cold straightened
2) In case of three-piece cylinders one
sufficiently only to help gripping and placing them in
specimen across longitudinal weld and
the testing machine jaws.
one on any one of the circumferential
welds. The specimen shall be taken For liquefied petroleum gases cylinders of 33.3 litre
alternately from top and bottom water capacity, the gauge width of 25 mm and gauge
circumferential welds on successive length of 5.65√S shall be taken (see Fig. 1A). The
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cylinders selected for test. In addition, one calculated value of the original gauge length may be
specimen from bung weld shall be taken. rounded off to the nearest multiple of 5 mm provided
3) Apart tfrom specimens from bung, the difference between the calculated and marked
circumferential and longitudinal seams, gauge length does not exceed 10 percent of the original
weld specimens from each of the non- gauge length. For steel other than IS 6240 specimens
pressure part attachments be drawn. shall be prepared as per the relevant steel specification.
5.2 Parent Metal Tensile Tests
Table 2 Tolerance on Dimensions of Test Pieces
5.2.1 These test methods are based on IS 1608 which Machined on Two Opposite Faces
may be referred in case further references are required. (Clause 5.2.2)
5.2.2 Sample Preparation All dimensions in millimetres.
A typical layout of tensile test specimen is given in Sl Nominal Dimension Tolerance on Form
Fig. 2. The dimensions shall be as per Table 1 and No. Values
(1) (2) (3)
tolerances on dimension shall be as per Table 2. The
i) 3 to 6 0.18
face and back of test specimen shall not be machined,
ii) Over 6 to 10 0.22
but shall represent the surface of the cylinder as iii) Over 10 to 18 0.27
manufactured. lf individual measurements of the iv) Over 18 to 30 0.33
v) Over 30 to 50 0.39
Table 1 Dimensions of Test Pieces NOTE — Dimensions of the ends of the reduced section of test
piece shall not differ in width by more than 0.1 mm.
Non-proportional
All dimensions in millimetres. 5.2.3 Mark the axis on the test specimen and also mark
over-lapping gauge length as shown in Fig. 2, in order
Sl Width Gauge Minimum Approximate
No. Length Transition Radius Total Length to save the results of tensile test in case fracture occurs
b L r L outside gauge length.
o t
(1) (2) (3) (4) (5)
5.2.4 Methods of Test
i) 40 200 25 450
ii) 30 200 25 375
5.2.4.1 Principle of test
iii) 25 100 25 300
iv) 12.5 50 25 200
The test consists in straining a test piece by tensile
v) 6 24 12 100
vi) 3 12 6 50 stress, generally to fracture, with a view to determine
the mechanical properties, that is, yield stress, tensile
NOTES
stress and percentage permanent elongation. The test
1 Notwithstanding the above, test pieces having a gauge length
equal to 5.65√S are permitted. Where ‘√S’ is the original cross- shall be carried out at ambient temperature unless
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sectional area of the test specimen. otherwise specified.
2 For any width from 3 mm to 25 mm a gauge length of 50 mm
5.2.4.2 Methods of gripping
may be used, the total length being adjusted accordingly.
3 A straight parallel test piece without enlarged ends is Test pieces should be held by suitable means, for
permissible for any size.
example, wedges, screwed holders, shouldered holders,
4 It is recommended that parallel length (L) of test piece shall
be between L + 1.5 √S and L + 2.5 √S.c etc. Every endeavour should be made to ensure that
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test pieces are held in such a way that the load is applied
5 Provided there is sufficient material, the parallel length (L)
c
used for arbitration purposes shall be L + 2 √S. as axially as possible.
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6 In case the gauge length is required to be proportional.
5.2.4.3 Accuracy of testing equipment
Conversion to proportional length shall be done as per IS 3803
(Part 1).
The testing machine shall be calibrated in accordance

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IS 3196 (Part 3) : 2012
1A Two-Piece Cylinders
1B Three-Piece Cylinders
FIG. 1 TENSILE SPECIMENS FOR ACCEPTANCE TEST

3
IS 3196 (Part 3) : 2012
FIG. 2 TENSILE TEST SPECIMEN
with IS 1828 (Part 1) and should be maintained to deflecting from straight line.
Grade 1.0 except when Grade 0.5 is required by the
5.2.4.6 Determination of tensile strength
standard of the material.
When determining tensile strength, the test piece shall
5.2.4.4 Testing technique
be loaded so that in the plastic range, the rate of
For most practical purposes the straining rate may be separation of the cross heads of the testing machine,
assessed in terms of loading rate, taking into account expressed as a percentage of the parallel length per
the following factors: minute, shall at no moment, be not greater than twice
the specified minimum elongation + 10.
a) Apparent elastic compliance (k) of the testing
machine and test assembly; The speed of testing should be as uniform as possible
b) Area of cross-section of the test piece; and and the change of speed from one range to the other
should be made gradually and without shock.
c) Parallel length of the test piece.
Tensile strength is determined as maximum load
For measurement of yield stress, a rate of strain during
divided by the original cross sectional area of the test
plastic deformation not exceeding 0.15/min is
piece, that is, stress corresponding to the maximum
recommended which is normally obtained in number
load.
of testing machines in common use. In addition to the
recommended rate of straining, the rate of stressing 5.2.4.7 Determination of percentage permanent
shall be between 20 to 30 Nmm-2 s-1 in the elastic range, elongation
to avoid, amongst other things, errors due to inertia
The percentage elongation after fracture shall be
effects. The controls of the testing machine should not
expressed to the nearest one percent. This is permanent
be adjusted after 90 percent of the expected yield force
elongation of the gauge length of the test piece after
has been reached.
fracture, expressed as a percentage of the original gauge
5.2.4.5 Determination of yield stress length.
The values of upper yield stress (R H) and lower yield Care shall be taken to place the broken parts of the test
e
stress (R L) can only be determined when a stress- pieces along the axis and proper contact between the
e
strain diagram is obtained. For the purpose of this broken parts of the test piece ensured, when measuring
standard upper yield stress is to be determined. the final length between gauge marks.
Upper yield stress (R H) is the value of stress measured The test results are regarded as valid, irrespective of
e
at the commencement of plastic deformation at yield the position of the fracture, provided that the minimum
(see Fig. 3A and 3B) or the value of stress measured at elongation specified has been obtained. If the minimum
the first peak obtained during yield even when that elongation specified is not obtained, the results of a
peak is equal or less than any subsequent peaks test shall be discarded, if the distance between the
observed during plastic deformation at yield. fracture and the nearer gauge mark is less than one-
third of the gauge length. In case non-proportional
In case yield point is not clear, a straight line shall be
gauge length has been used corrections shall be made
drawn on the curve as shown in Fig. 3C, and yield
for elongation according to IS 3803 (Part 1).
load taken at the point ‘A’ from where the curve starts

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IS 3196 (Part 3) : 2012
INITIAL
INITIAL
TRANSIENT
TRANSIENT
EFFECT
EFFECT
FIG. 3 STRESS STRAIN DIAGRAM
5.3 Tensile Test on Weld Joint 5.3.1.1 The test specimen shall be cut out transversely
to the weld and shall be the full thickness of the
5.3.1 Sample Preparation
material at the welded joint. In preparing the test
Test specimen cut from the cylinder across the weld specimen, the face and back shall be machined or
shall be prepared with radius reduced dimension at the ground to remove backing strip or joggling and the
weld joints as shown in Fig. 4. weld bead on the face and root side. The face and back
All dimensions in millimetres.
FIG. 4 RADIUS REDUCED T RANSVERSE TENSILE TEST SPECIMEN
5