IS 3181 : 1992

(Reaffirmed 2001)
Edition 3.1
(2005-05)

Indian Standard
CONVEYOR BELTS — FIRE RESISTANT
CONVEYOR BELTING FOR UNDERGROUND
MINES AND SUCH OTHER HAZARDOUS
APPLICATIONS — SPECIFICATION
( Second Revision )
(Incorporating Amendment No. 1)

UDC 621.867.2 : 539.434 : 622.647.2

© BIS 2005

BUREAU OF INDIAN STANDARDS

MANAK BHAVAN , 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

Price Group 9
Pulleys and Belts Sectional Committee, LM 09

FOREWORD

This Indian Standard (Second Revision) was adopted by the Bureau of Indian Standards, after the
draft finalized by the Pulleys and Belts Sectional Committee had been approved by the Light
Mechanical Engineering Division Council.
This standard was originally published in 1966 soon after indigenous manufacture of PVC
underground Colliery Conveyor belting was started in India. It was done based upon
contemporary specification of the National Coal Board, UK.
A revision was issued in 1978 primarily to convert all values into SI units and also include some
new ranges of width dimensions. There were minor modifications in tensile strength, tear
strength, etc.
In the last 28 years or more since the manufacture of PVC Underground Colliery Conveyor belting
was started in India, substantial improvements and upgradation have taken place in the UK
leading to a far better type of conveyor belting with 100 percent assurance on safety relating to fire
hazards.
The current revision apart from rationalising a few aspects of the standard has been restructured
to include the latest method for fire resistance namely Propane Gallery Test. This is a fire
propagation test and going to be of immense value to the end user particularly in most hazardous
gassy applications. This revision also includes modifications of the drum friction test equipment to
give more accurate measurement of the temperature of the drum surface. Experience using the
new testing apparatus for laid down in this standard has shown that consistently higher
temperatures have been recorded than those obtained using the apparatus laid down in earlier
version of the standard. In view of this, the specified maximum drum surface temperature has
been raised, but it does not reduce the severity of test.
In preparation of this standard considerable assistance has been derived from the following:
ISO 252 : 1988 Conveyor belts — Ply adhesion between constitutive elements — Test method
and requirements. International Organization for Standardization.
ISO 282 : 1975 Conveyor belts — Sampling. International Organization for Standardization.
ISO 284 : 1982 Conveyor belts — Electrical conductivity — Specification and method of test.
International Organization for Standardization.
ISO 432 : 1989 Ply type conveyor belts — Characteristics of construction. International
Organization for Standardization.
ISO 505 : 1982 Conveyor belts — Tear propagation resistance of the carcass — Method of test.
International Organization for Standardization.
NCB Specification No. 158 — 1980 (and amended in 1985) Fire resistant conveyor belting.
National Coal Board, UK.
BS 3289 : 1982 Specification for conveyor belting for underground use in coal mines. British
Standards Institution.
This edition 3.1 incorporates Amendment No. 1 (May 2005). Side bar indicates modification of the
text as the result of incorporation of the amendment.
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 IS 2 : 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 3181 : 1992

Indian Standard
CONVEYOR BELTS — FIRE RESISTANT
CONVEYOR BELTING FOR UNDERGROUND
MINES AND SUCH OTHER HAZARDOUS
APPLICATIONS — SPECIFICATION
( Second Revision )
1 SCOPE Table 1 Designation and Properties of
This standard covers the requirements for fire Finished Belting
resistant conveyor belting made from fire
resistant compounds and textile reinforcements ( Clause 4 )
for use in underground mines and such other Belt Desig- Breaking Elongation Tear
hazardous applications where risk of fire is Type nation Strength at Break Stren-
involved. Minimum Minimum gth
Mini-

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2 CONSTRUCTION Longi- Trans- Longi- Trans- mum
tudinal verse tudinal verse
2.1 The belting shall be of solid woven construc- kN/m kN/m Percent Percent kN
tion or shall consist of plies of woven fabric and 1 2 700 470 235 17 18 1.00
shall be impregnated with a fire resistant com-
2 3 000 525 265 17 18 1.00
pound and have fire resistant covers, the whole
being fused or vulcanised together in accordance 3 3 500 610 265 17 18 1.09
with the best manufacturing practice. 4 4 000 700 352 17 18 1.09
2.2 The edges of the belting shall be completely 5 5 000 875 352 15 18 1.18
sealed by fire resistant compound. 6 6 500 1 140 352 Not specified 1.54
2.2.1 Where the edge cover material is 8 8 000 1 400 352 Not specified 1.54
manufactured and applied separately (its width
shall not be more than 5 mm) to produce good NOTE — When belting is required for special applica-
tions with breaking strengths above or below those in
adhesion it shall be fused or vulcanized to the Table 1, the form of construction and minimum pro-
edges of the surface covers and the fabric. properties shall be agreed between purchaser and
manufacturer.
3 FABRIC
The fabric used shall be evenly and firmly 6 WIDTH
woven and substantially free from foreign 6.1 The belting shall be manufactured in the
matter and manufacturing fault as is normal in following nominal widths: 500, 600, 650, 750,
the best manufacturing practice. 800, 900, 1 000, 1 050, 1 200, 1 400 and
4 DESIGNATION AND PROPERTIES OF 1 600 mm.
BELTING NOTE — Where necessary subject to agreement
between purchaser and supplier, widths other than the
Belting complying with the requirements of above may be specified.
this specification shall be designated by belt 6.2 The width of the belting shall at no point vary
type according to its physical properties as from the specified dimensions by more than the
given in Table 1. amount given in col 2 of Table 2 but in any one
5 LENGTH length of belting the total variation in width shall
not exceed the figures in col 3 of Table 2.
The length of belting shall be specified by the
purchaser. The tolerance on length on individual 7 BELT AND CARCASS THICKNESS
rolls shall be + 2 percent to – 0 5 percent and the 7.1 The belt thickness shall be measured in
total length supplied for a specific installation accordance with the method given in Annex A.
shall be not less than the specified length Using this method, the difference between any
ordered. two to the seven measurements of the belt
NOTE — However, lengths outside these limits thickness shall not exceed.
occasionally resulting due to manufacturing limitations
may be accepted as agreed between manufacturer and a) 1 mm for a belt of which the mean
purchaser. thickness does not exceed 10 mm.
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IS 3181 : 1992

b) 10 percent of the mean belt thickness for a a) 50 percent of the specified cover thickness
belt of which the mean thickness exceeds for cover of less than 1 mm.
10 mm. b) 70 percent of the specified cover thickness
Table 2 Tolerances of Width for cover of 1 mm or more.
( Clause 6.2 ) 8.4 Where belting is to be used in conditions
which require additional protection of the
Width of the Tolerance Total Variation carcass or improved abrasion resistance, covers
Belting in Any One thicker than specified shall be permitted in
Length
specified mean thickness of 1 mm, 2 mm or 3 mm.
(1) (2) (3)
8.5 Where a different material is fused or vul-
Up to and including + 10 mm
width of 600 mm – 5 mm 10.0 mm
canised on to existing specified cover material
as additional cover thickness, the specified
For width over + 2% of width
600 mm – 1% of width 2% of width
cover thickness will refer only to the thickness
of the additional cover material.
7.1.1 When measured in accordance with the
9 JOINT IN FABRIC
method described in Annex A, the mean belt
thickness shall not vary by more than 1 mm 9.1 Transverse Joint
with respect to that specified for belts up to 9.1.1 In solid woven belting, there shall be no
10 mm thickness or shall not vary by more than transverse joint in the carcass.
10 percent of the specified value for belt
thickness over 10 mm thickness. 9.1.2 Transverse joints in the fabric plies of
multi-ply belts shall be at an angle of not greater
7.2 The carcass thickness shall be derived by than 60º and not less than 45º to the longitudinal
subtracting the sum of the mean thickness of axis. The minimum distance between transverse
top and bottom covers, as measured in joints shall be as follows:
accordance with the method given in Annex A
from the mean belt thickness as measured in a) Outer plies — Joints in outer plies shall
accordance with the method given in Annex A. be not less than 100 m apart in the same
ply. The adjoining edges shall butt
7.3 The mean belt thickness ( see 7.1 ) and the closely together and shall not overlap.
derived carcass thickness ( see 7.2 ) shall not be
less than as given below: b) Inner plies — Joints in inner plies shall
be not less than 15 m apart in the same
Minimum Belt and Carcass Thickness
ply. and there shall be not more than
Belt Type Belt Thickness Carcass Thickness two joints in any one ply in each 200 m
mm mm of belting. The adjoining edges shall butt
1 Not specified Not specified closely together and shall not overlap.
c) Adjacent plies — Joints in adjacent plies
2 Not specified Not specified
shall be not less than 3 m apart.
3 7.5 5.9 d) Non-adjacent plies — Joints in non-
4 8.0 6.4 adjacent plies shall be separated by a
distance not less than the width of the
5 8.5 6.9 belting.
6 and above 9.0 7.4
9.2 Longitudinal Joints
8 COVER THICKNESS 9.2.1 There shall be no longitudinal joints in
8.1 Both the carrying and non-carrying faces the carcass of solid woven belts.
of the belting shall be protected by covers 9.2.2 For plied belts, the number of longitudinal
of specified thickness appropriate to the joints in the plies shall be as given in Table 3. The
operational requirement and when measured in adjoining edges shall butt closely together and
accordance to the method described in Annex A, shall not overlap.
the average thickness value shall not fall below Table 3 Number of Longitudinal
the specified value by more than 10 percent. Joints in the Plies
8.2 The cover material shall consist of fire resis- Width of Belt No. of Longitudinal Joints
tant compound.
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Outer Ply Inner Ply

8.2.1 The thickness of the cover shall be as
Up to and including 0 0
specified by the purchaser. 1 200 mm
8.3 The cover thickness within 25 mm of the Above 1 200 up to and 1 2
belt edge shall be not less than: including 1 600 mm

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 IS 3181 : 1992

10 FREEDOM FROM DEFECTS required to strip the edging from the belt at
The belting shall be straight when laid out flat. grip separation rate of 50 mm/min is not less
The surface of finished belting shall be free from than 2 6 kN/m of belt thickness when measured
blisters, pitting or other major surface flaws and in a direction parallel to the edges of the belt.
shall be completely sealed against ingress of 14 ELECTRICAL RESISTANCE
moisture.
The electrical resistance shall be measured in
11 FULL THICKNESS BREAKING accordance with the method described in
STRENGTH AND ELONGATION Annex E and the average value on both the upper
and lower surfaces of the belting shall be not
11.1 The longitudinal and transverse breaking
greater than 3 × 108 ohms.
strength and the elongation of the finished
belting shall be the average values determined 15 FIRE RESISTANCE
in accordance with the method described in
Annex B. The breaking strength and elongation 15.1 Drum Friction Test
of the finished belting shall be not less than the a) The belting shall be tested as per method
value given in Table 1. described in Annex F and there shall not be
11.2 Elongation at Reference Load any visible sign of flame or glow on any part
of any one of the test pieces of belting either
The elongation of the finished belting in the during each test or after each test piece
longitudinal direction at the reference load (viz breaks. The temperature of the surface of
one tenth of the specified longitudinal full the drum during each test shall not exceed
thickness breaking strength) shall not be 325ºC.
greater than 4 percent. b) The drum friction test should be carried
NOTE — The elongation at the reference load is in- out for the purpose of approval of a given
tended as a control test only and cannot be related exactly
to stretch characteristics in service. The elongation construction as a type test.
parameters at reference load and at break as stipulated 15.2 Spirit Burner Flame Test
in 11.2 and Table 1 respectively shall be applicable for
belting up to and including Type 5. For other types viz When tested as per method described in Annex G,
Type 6 and Type 8, the parameters remain unspecified till the belt shall comply with the following:
sufficient data is generated based on the actual
performance of these type of belts. a) For the six test pieces with the outer
covers intact, the average time for all
12 TEAR STRENGTH
visible flame or glow to disappear after
The tear strength of the finished belting shall withdrawal of the burner shall not exceed
be measured as described in Annex C and the 3 seconds. No individual test piece shall
average value in sense A and in sense B shall flame or glow for more than 10 seconds.
be not less than the values given in Table 1. In the event that in individual test piece
13 ADHESION continue to flame or glow for more than
10 seconds and the average flame or glow
13.1 The adhesion between cover and carcass
time does not exceed 3 seconds a further
and between adjacent plies in plied construction
belting shall be tested longitudinally and six test pieces shall be tested. The average
transversely as per method described in Annex D flame or glow time for these further test
and shall be not less than the values given in pieces shall not exceed 3 seconds and no
Table 4. individual test piece shall exhibit flame or
glow for more than 10 seconds.
Table 4 Adhesion Requirements
b) For the six test pieces with outer covers
Adhesion Adhesion removed, the average time for all visible
Between Cover Between flame or glow to disappear after the with-
and Carcass Adjacent Plies drawal of the burner shall not exceed
( kN/m ) ( kN/m ) 5 seconds. No individual test piece shall
Average of the two 3.15 3.5 flame or glow for more than 15 seconds.
mean values of
force from the two
In the event of individual test piece flames
tests or glows for more than 15 seconds and the
Lower of the two 2.6 2.6 average flame or glow time does not exceed
minimum values 5 seconds, a further six test pieces shall be
of force from the tested. The average flame or flow time for
two tests these further test pieces shall not exceed
5 seconds and no individual test pieces shall
13.2 Edge Adhesion
flame or glow more than 15 seconds.
Adequate adhesion between the edge strip and
15.3 Propane Burner Test
the edge of the belt can normally be checked by
visual and manual inspection. Adhesion shall The belting shall be tested as per the method
be considered to be satisfactory if the force described in Annex H and shall be self
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IS 3181 : 1992

extinguishing, after the propane flame has Table 5 Sampling

been removed, all combustion shall cease and a
minimum of 250 mm long full width portion on ( Clause 17.1 )
each test piece shall remain undamaged at the Length of Belting Ordered Number of
completion of the test. In the event of one test of One Type and Samples
piece failing, the sample shall be deemed to Width in m
have failed the specification requirement.

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From Up to and Including
NOTE — Till such time facilities for conducting pro- — 500 1
pane burner test are developed in the country. it shall
be a type approval test and may be got done from either 501 1 000 2
British Coal or any other alternative source. 1 001 2 000 3
16 MARKING 2 001 3 500 4
3 501 5 000 5
The belting shall be marked on one face with the 5 001 7 000 6
following information using characters not less
7 001 10 000 7
than 20 mm high. Marking shall be repeated at
For each addi- 3 500 1
a maximum longitudinal spacing of 10 m, at tional
approximately 100 mm from the left and right
edges alternately. In the case of belts of unequal 17.2 The samples shall be cut from the belting
cover thickness the marking shall be on the not less than 24 h after the completion of manu-
thicker cover: facture.
a) Letters or trade mark identifying the
manufacturer. 17.3 Retest and Rejection
b) Year of manufacture. Should any sample fail to comply with the
c) Belt type number. specified test requirements, two additional
d) Specified cover thickness. samples shall be drawn and tested after
e) The number of this Indian Standard i. e., conditioning them in a standard atmosphere of
IS 3181. 65 ± 5% relative humidity and 27 ± 2ºC
temperature for 3 days before testing. In the
The marking shall be sufficiently durable to
event of either of these two samples failing to
withstand abrasion during transport, storage,
comply with the test requirements, the supply
installation and service.
shall be rejected. If both the samples pass the
17 SAMPLING AND TESTING tests, the supply shall be accepted.
17.1 The number of samples to be tested for 18 PACKING
compliance with the requirements of this
specification shall be in accordance with Table 5. The belting shall be packed as mutually agreed
Each sample shall be full belt width and not less upon between the purchaser and the manufac-
than 600 mm long. turer.

ANNEX A
( Clauses 7.1, 7.1.1, 7.2 and 8.1 )

METHOD OF MEASURING BELT AND COVER THICKNESS

A.1 METHOD OF MEASURING BELT The working force at the contact surface,
THICKNESS measured with a dial gauge in vertical position
shall be 0.50 ± 0.20 N.
A-1.1 The belt thickness is measured on a cut
edge of unstripped belt.
A-1.3 Preparation of Test Piece
A-1.2 Apparatus
A micrometer dial gauge graduated in divisions Cut the belt across its full width at right angles
of 0.01 mm. to the surface and edges of the belt ensuring that
The dial gauge is firmly held in a rigid stand the line of the cut is not within 50 mm of any
over a flat baseplate of width at least 100 mm embossed marking on the surface of the belt.
and is fitted with a flat contact of diameter
19 ± 2 mm which is square to the plunger and Mark but do not cut the sample at each of the
parallel to the baseplate. seven points shown in Fig. 1A.

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 IS 3181 : 1992

A-1.4 Procedure B directly opposite A. A point C shall be

Hold the test piece flat on the base plate, with marked on the same edge as B and 50 mm from
the dial gauge contacting the belt at the it. The belt shall be cut on the line AC as shown
positions indicated in Fig. 1A, by means of in Fig. 1B.
finger pressure each side of the position of the The cut section of the belt shall be divided
dial gauge contact. Support the belt at the same between points A and C into eight parts by
height as the surface of the base plate of the seven lines extending across the cut edge. The
dial gauge. Measure the thickness of the belt at two parts adjacent to the edges shall each
each of the seven points shown in Fig. 1A, each extend 25 mm into the belt and the remaining
value being rounded to two decimal places. portion shall be divided into six equal parts.
NOTE — The points may be marked on a line of an A-2.4 Procedure
angle to the edge of the test piece as in Fig. 1B. This will
enable both belt thickness and cover thickness A-2.4.1 For each cover, measure the distance
measurements to be obtained from one set of markings. between the surface of the belting and the top
A-1.5 Expression of Results of the fabric knuckles to the nearest half
division at the fabric knuckles nearest to each
Record each of the seven thicknesses and of the seven lines, as shown in Fig. 1B.
calculate the mean belt thickness.
A-2.4.2 Measurement of minimum thickness
A-2 OPTICAL METHOD OF MEASURE- within 25 mm of belt edges — Examine the
MENT OF COVER THICKNESS cover thickness within 25 mm of the belt edges
A-2.1 The top and bottom cover thickness shall and measure the minimum distance between
be measured on a cut edge of unstripped belt. the surface of the belt and the fabric knuckles
Measurement shall be made of the distance as shown in Fig. 1B, for each cover.
along the normal from the face of the belt to the NOTE — t1 and t7 are the distances between the surface
top of the fabric knuckle as shown in Fig 1B. (top cover) of the belt and the exposed fabric at the
nearest knuckle to each of the two lines D and E. t2 to t6
A-2.2 Apparatus are the distances between the surface (top cover) of the
belt and the exposed fabric at the nearest knuckle to
The measuring instrument shall be an optical each of the five lines
magnifier incorporating a scale graduated in Cover thickness t1 + t2 + t3 + t4 + t5 + t6 + t7
division of 0.01 mm. (top cover) = ---------------------------------------------------------------------------------------
-
7
A-2.3 Preparation of Test Piece where visual inspection reveals a localised thin
The belt shall be cut across its full width at portion(s) of cover, the average cover thickness
right angles to the surface and obliquely to the ta + tb + tc + td
edge of the belt. --------------------------------------
- is determined over four adjacent knuckles
4
The line of the cut, which shall not intersect of the fabric within the affected area.
any embossed markings on the surface of the tx and ty are the minimum readings within 25 mm of the
belt, shall be determined by marking one edge edges. The same procedures are repeated for the bottom
of the belt at a point A and the other by a point cover.

W – 50
X = -----------------
- mm
6

FIG. 1A MEASUREMENT OF BELT THICKNESS

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IS 3181 : 1992

All dimensions in millimetres.

FIG. 1B MEASUREMENT OF COVER THICKNESS

A-2.5 Expression of Results c) The thickness of any localised thin cover
shall be the average of the four measure-
a) Record each measurement. ments made within the affected areas.
b) The mean cover thickness shall be the d) Cover thickness within 25 mm of the belt
average of the seven measurements made edges shall be the minimum cover thickness
adjacent to the dividing lines. measurements made within these areas.

ANNEX B
( Clause 11.1 )

METHOD OF TEST FOR BREAKING STRENGTH AND ELONGATION

B-1 PRINCIPLE B-2 APPARATUS

A tensile testing machine complying with the
The longitudinal and transverse breaking
following requirements shall be used.
strengths and elongations at break shall be
measured on samples of conveyor belting with B-2.1 The accuracy of the machine shall be
covers intact using dumb-bell shaped test pieces. within 1.0 percent.
B-2.2 The range of the machine shall be chosen
The test pieces shall be held in the grip of a so that the forces to be measured come within
suitable tensile testing machine. The grip shall 80% of the full scale deflection.
be separated at a defined rate and the
maximum load observed before the test piece B-2.3 For the tensile strength test, the machine
breaks shall be recorded as the breaking shall have either an autographic force recorder
strength of the test piece. The elongation at or a maximum force indicator. For the adhesion
break shall also be recorded. and tear tests the machine shall have an

6
 IS 3181 : 1992

autographic force recorder and the natural

frequency, inertia and damping characteristics
shall be such that it is capable of recording
fluctuation of the separating force.
B-2.4 The force shall be applied smoothly
without any jerking or intermittent action and
the power shall be sufficient to stress the test
piece to the point of fracture at a rate of travel
of 100 ± 5 mm per minute for the tensile
strength test and 50 ± 2.5 mm per minute for
the adhesion and tear tests.
B-2.5 The jaws of the machine shall move with-
out undue friction and in correct alignment. FIG. 3 EXAMPLE OF SUITABLE DOUBLE
COMPARTMENT GRIP
B-2.6 The jaws of the machine shall hold the
test piece without slip and without damage. B-3 TEST PIECE SHAPE AND
NOTES DIMENSIONS
1 An example of a suitable grip is shown in Fig. 2. For The test piece shall conform on both faces to the
very thick belts, double compartment grips as shown in shape and dimensions shown in Fig. 4 and shall
Fig. 3 have been found to be more suitable.
be cut by the use of a suitable die such as
2 The serrations of the grips shall be suitable to give shown in Fig. 5. The test pieces shall be
adequate grip to the belt without damage to the carcass.
representative of the condition and thickness of
3 Hydraulically operated unserrated grips or other such
devices may be used for this test provided that they do
the main body of the belt.
not cause the test piece to break near the jaws rather B-4 PREPARATION OF TEST PIECES
than at its centre.
B-4.1 Cut six test pieces, three in the
longitudinal direction parallel to the length of
the belt and three in the transverse direction at
right angles to the length of the belt.
NOTES
1 The test pieces shall be cut from places widely spaced
from each other, so as to be representative of the whole
area of the sample of belting.
2 The test piece shall contain no joints.
3 No test piece shall be cut from the sample with its
longitudinal edge less than 12 mm from an edge of the
sample.
FIG. 2 EXAMPLE OF SUITABLE SINGLE
COMPARTMENT GRIP

All dimensions in millimetres.

FIG. 4 TENSILE TEST PIECE

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IS 3181 : 1992

B-5.2 Determine the elongation values by

measuring on the centre line of the test piece
the distance between the reference lines of the
defined 100 mm gauge length, as shown in
Fig. 4, at the moment of break of the test piece.
NOTE — This may conveniently be done by following
the extension with dividers or by means of a suitable
All dimensions in millimetres. extensometer operating in direct contact with the test
piece.
FIG. 5 CROSS SECTION OF DIE
B-6 EXPRESSION OF RESULTS
B-4.2 Condition the test pieces in a standard
atmosphere of 65 ± 5 percent relative humidity B-6.1 The breaking strength as recorded of
and 27 ± 2ºC temperature for three days and each of the six test pieces shall be reported
immediately test at that temperature and separately. The average value for each of the
relative humidity. two sets of three tests on the test pieces cut
longitudinally and transeversely from the belt
B-5 PROCEDURE shall be calculated and reported.
B-5.1 Place the end of the test piece B-6.2 The elongation at break of the test piece
symmetrically in the grips of the tension shall be expressed as a percentage of the initial
testing machine and separate the grips at a 100 mm gauge length.
constant rate of transverse at a speed of
100 ± 5 mm/min, until the test piece breaks. The elongation at break of each of the six test
Record the maximum breaking strength. pieces shall be reported separately together
with the average value for each of the two sets
NOTE — The results of breaks occurring outside the
defined section marked by reference line shall normally of three tests on the test pieces cut
be discarded and retests made. longitudinally and transversely from the belt.

ANNEX C
( Clause 12 )

METHOD OF TEST FOR TEAR STRENGTH

C-1 PRINCIPLE C-3 TEST PIECE

The force required to extend a cut made in a C-3.1 Cut two test pieces parallel to the length of
test piece taken from a sample of conveyor the belt each being a rectangular strip of the full
belting with covers intact is determined by thickness of the belt and measuring 50 ± 1 mm
means of a suitable tensile testing machine. wide and 300 mm long. Cut each test piece down
C-2 APPARATUS the centre, parallel with the sides, for a length of
approximately 100 mm from the end so as to form
Tensile testing machine complying with the two legs as shown in Fig. 6.
requirements given in Annex B.

All dimensions in millimetres.

FIG. 6 TEST PIECE FOR TEAR TEST

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 IS 3181 : 1992

C-3.2 Mark each test piece with a letter T on three days and immediately test at that
the top cover of the belt. This mark is made at temperature and relative humidity.
the same end of each test piece in relation to
the run of the belt as shown in Fig. 7. C-5 PROCEDURE
C-5.1 Hold the two legs of a test piece in the
grips of the testing machine, one in each grip.
Clamp the legs, with the inner cut edges
located at the centre of the grips and the legs
set parallel to the direction of the traverse.
Separate the grips at a constant rate of
transverse at a speed of 50 ± 2.5 mm/min, and
make an autographic record of the force
required to tear the test piece a further
100 mm.
C-5.2 Ignore the initial rise of the trace on the
autographic record and determine the mean
tearing force from the autographic record over a
length of trace corresponding to not less than
75 mm of tearing.
C-5.3 Test one test piece in Sense A and the
other in Sense B as shown in Fig. 8.

C.6 EXPRESSION OF RESULTS

FIG. 7 ARRANGEMENT AND MARKING ON C-6.1 Report the mean tearing force in kN.
TEST PIECE FOR TEAR TEST
C-6.2 The following results shall be recorded:
C-4 CONDITIONING OF THE TEST PIECE
a) The mean tearing force of each of the two
C-4.1 Condition the test pieces, prior to test in test pieces from the autographic record
a standard atmosphere of 65 ± 5 percent over a length of the trace corresponding to
relative humidity and 27 ± 2ºC temperature for at least a 75 mm tear.

All dimensions in millimetres.

FIG. 8 ILLUSTRATION OF THE TWO SENSES OF TESTING FOR TEAR TEST

9
IS 3181 : 1992

b) In cases where the threads of the fabric fluctuation of force occur, carry out the following
pull out before direct tearing takes place, procedure:
a statement to this effect is made and the a) Draw a mean curve through the centres of oscillation
of the trace, this represents the tearing force curve.
mean tearing force recorded.
b) Determine the mean height of the tearing force curve
NOTE — In determining the mean tearing force from either visually or by suitable graphical means and
the autographic record, a visual determination may be represent it by a straight line drawn parallel to the base
taken by mutual consent of the manufacturer and the line of the autographic record, the height of the line to
purchaser. In cases of dispute or where substantial scale defines the mean tearing force.

ANNEX D
( Clause 13.1 )

METHOD OF TEST FOR ADHESION

D-1 PRINCIPLE D-5.2.2 Repeat the test using the same test
The force required to strip one ply from the piece for each consecutive ply to the middle of
next and also to strip the cover from the carcass the test piece. Repeat the tests on the second
it determined by means of a suitable tensile test piece of the pair commencing with the
testing machine. opposite cover and again working to the middle
of the test piece.
D-2 APPARATUS
D-5.3 Expression of Results
Tensile testing machine complying with the
requirements given in Annex B. Express the results in kN/m.
D-5.3.1 For test pieces taken both parallel to the
D-3 TEST PIECE
length of the belt and at right angles to the length
Rectangular strip 25 ± 1.0 mm wide and 300 mm of the belt, the following are to be reported:
long. a) between each cover and adjacent ply, the
D-4 PREPARATION OF TEST PIECES average of the two mean values of the
stripping force from the two tests and the
Cut one pair of test pieces in the longitudinal
lower of the two minimum values of strip-
direction parallel to the length of the belt and
ping force from the two tests.
one pair in the transverse direction at right
angles to the length of the belt, each test piece b) between adjacent plies, the average of the
measuring 25 ± 1 mm wide and 300 mm long two mean values of the stripping force from
and having clean edges. Cut the test piece from the two tests and the lower of the two
places widely spaced from each other so as to be minimum values of stripping force from the
representative of the sample of belting. two tests.
D-5 PROCEDURE D-5.3.2 In determining the mean and minimum
values of stripping force from the autographic
D-5.1 Expose test pieces in a standard atmos- record, a visual determination may be taken by
phere of 65 ± 5 percent relative humidity and mutual consent of the manufacturer and
27 ± 2ºC temperature for at least 24 hours and purchaser. In case of dispute, or where
then immediately test at that temperature and substantial fluctuations of force occur, carry out
humidity. the following procedure:
D-5.2 At one end of the test piece separate one of
the covers from the first ply for a distance of a) Draw a mean curve through the centres
approximately 75 mm. Fix the separated ends in of oscillation of the trace, this represents
the grips of the tensile testing machine and make the stripping force curve.
an autographic record of the force required to b) Determine the mean height of the strip-
strip a further 100 mm with a rate of traverse of ping force curve, either visually or by
the driven jaw of 50 ± 2.5 mm/min. Ensure that suitable graphical means and represent
the unstripped part of the test piece is free from it by a straight line drawn parallel to
support during the test. the base line of the autographic record,
the height of the line to scale defines the
D-5.2.1 Ignore the initial rise of the trace on the
mean stripping force.
autographic record and determine the mean and
minimum values of stripping force from the auto- c) The minimum height of the stripping
graphic record over a length of trace correspond- force curve defines the minimum
ing to not less than 75 mm of stripping. stripping force.

10
 IS 3181 : 1992

ANNEX E
( Clause 14 )

METHOD OF TEST FOR ELECTRICAL RESISTANCE

E-1 PRINCIPLE E-2.3 Polythene Base Sheet

The electrical resistance is determined between A clean sheet of polythene or other material with
electrodes placed on the surface of the belt. resistivity not less than that of polythene and of
minimum dimensions of 300 mm × 300 mm ×
E-2 APPARATUS 2 mm thick.
E-2.4 Electrode System
E-2.1 Measuring Instrument
Each electrode system shall comprise two
The resistance measuring instrument shall electrodes of soft thin metal foil consisting of a
cover the range 106 ohms (1 megohm) to circular disc 25 mm in diameter with a
1010 ohms (10,000 megohms) and be accurate concentric annulus having internal and external
to within ± 5 percent of the true value over this diameters of 125 mm and 150 mm respectively
range. The potential applied to the electrode as shown in Fig. 10. Care is taken to ensure
under test is between 40 and 1 000 V d.c. and is accuracy of the dimensions of the electrodes, but
chosen so that not more than 1 W is dissipated the symmetry of the annulus about the centre
in the test piece. disc is not critical. Electrode system shall be
applied to each of the test areas centrally.
E-2.2 Brass Contact Pieces
NOTES
The brass contact pieces shall consist of a cylin- 1 Suitable foils are as follows:
der and a ring of dimensions as given in Fig. 9.
a) For general use : Tin on lead, 1.5% tin,
The lower surface of each contact piece is 98.5% lead, 0.025 mm
machined flat, polished and clean, each contact thick 3.5 m2/kg.
piece is provided with a flexible insulated load.
b) For indented surface : Soft tin foil, 98.25% tin,
1.25% antimony, 0.5%
copper:

i) 0.005 6 mm thick,
25m2/kg

ii) 0.007 6 mm thick,

18 m2/kg

2 The foil electrodes may be omitted if the belt surface is

sufficiently smooth and flat to enable the liquid contact
agent to maintain continuous contact between the belt
and brass contact pieces, but with other surfaces the
omission may result in the indicated resistance being
higher than the true resistance.

All dimensions in millimetres.

FIG. 9 TEST LAYOUT SHOWING SUITABLE

All dimensions in millimetres.
WORKING DIMENSIONS OF BRASS CONTACT
PIECES FIG. 10 ELECTRODE SYSTEM

11
IS 3181 : 1992

E-3 PREPARATION OF TEST PIECE Place the belting immediately in the following
E-3.1 General condition for two hours:

Prepare two test areas on the upper surface of a) Temperature 27ºC ± 2ºC
the sample of belting and two on the lower b) Relative humidity 65 ± 5 percent
surface, each test area measuring not less than
300 mm × 300 mm. Test the samples without delay in the same
ambient conditions.
E-3.2 Surface Cleaning
Place the polyethylene sheet underneath the
Clean the surfaces of the test areas by dusting belting immediately below the test areas and
and rubbing with fuller’s earth (B. P. Grade) mount the brass contact pieces in position on
using a clean pad of cloth or cotton wool. After the electrodes.
all traces of powder have been cleaned away,
wipe over the surfaces with a clean pad Run the leads from these contact pieces direct
moistened with distilled water and then rub to the measuring instrument so that the outer
dry with a clean cloth. ring electrode is always connected to the
earthed or low potential terminal and the inner
E-3.3 Application of Electrodes cylinder to the higher potential terminal.
Apply the electrode system centrally on the test Ensure that these leads do not touch each
area. other, the belting, or any part of the apparatus
Attach the electrodes to the test areas by a con- except the terminals to which each is
ducting liquid contact agent consisting of: connected. Connect all earth terminals to the
same point.
Anhydrous polyethylene — 4 part by mass
glycol of relative mole- Apply the test potential from the measuring
cular mass 600 instrument to the test area and measure the
resistance when a steady indication is obtained.
Soft soap — 1/200 parts by
Apply the test potential for a maximum of a five
mass minutes.
Water — 1 part by mass
Avoid breathing on the test areas as any
Ensure that liquid coatings of the same dimen- condensation of moisture on to these surfaces
sions as the foil electrodes form on the surface. may lead to gross inaccuracies in the resistance
NOTE — This may be conveniently accomplished with measured.
two felt pads of the same dimensions as the electrodes,
moistened with the contact agent. Repeat the test in turn on the remaining three
Rub the electrodes on to the test surface with a finger or
test areas.
small soft pad. If the surface is indented ensure that E-5 TEST REPORT
after rubbing the foil electrodes clearly follow the
indentations. Do not smear the contact agent on the The following results shall be reported:
surface between the central disc and the annulus. Wipe
away any small excess with a clean cotton wool pad. a) The electrical resistance measured on
each electrode system.
E-4 PROCEDURE b) The average value of the two resistance
Prepare and clean the sample of belting and measurements on the upper surface.
apply the electrodes without delay as described c) The average value of the two resistance
in E-3.3. measurements on the lower surface.

ANNEX F
( Clause 15.1 )

METHOD OF TEST FOR FIRE RESISTANCE (DRUM FRICTION TEST)

F-1 APPARATUS being rotated under all load conditions at
200 ± 5 rev/min. To achieve this a power supply
The general arrangement of the drum friction of at least 7.5 kW is required.
apparatus is shown in Fig. 11.
Detailed dimensions of the drum, shown in
F-1.1 Steel Drum Fig. 12 are given in order to standardize its
thermal characteristics. The variation in
The steel drum of external diameter 210 ± 1 mm, diameter along the length of any one drum is a
mounted on a horizontal axle and capable of maximum of 1 mm.

12
13

IS 3181 : 1992
All dimensions in millimetres.
FIG. 11 GENERAL ARRANGEMENT OF DRUM FRICTION TESTING APPARATUS
IS 3181 : 1992

Notwithstanding the dimensions and tolerances However, till such time, equipments are updated to
on drum diameter and shell thickness shown in measure the temperature of the drum surface from
inside as explained in F-1.2, measurement of the tem-
Fig. 12, the effect of wear down to a minimum perature of the outside surface of the drum shall be
shell thickness of 6 mm is permissible. permitted. Temperature of the surface of the drum
during the test when measured from outside surface
shall at no time exceed 300ºC.

All dimensions in millimetres.

All dimensions in millimetres. FIG. 13 ARRANGEMENT OF DRUM
FIG. 12 DRUM FOR DRUM FRICTION TESTING TEMPERATURE MEASURING DEVICE
APPARATUS
F-1.3 Tensioning System
F-1.2 Drum Temperature Measuring A tensioning system for applying tension to the
Device test piece as shown in Fig. 14 shall be used.
Principal dimensions of the tensioning system
A temperature measuring device to indicate the are given in order to standardize its moment of
temperature of the surface of the drum, com- inertia.
prising a thermocouple set with its tip not
greater than 0.5 mm below the surface, midway F-1.4 Air Current
along the drum. The method of mounting the
thermocouple is shown in Fig. 13. Suitable means shall be available for providing
an air current having a velocity of 2.0 ± 0.1 m/s
Care is taken to see that the effective ‘cold junc- when measured with the test piece in position
tion’ temperature is compensated for or at a distance of 200 mm from the surface of the
alternatively is measured and the appropriate drum.
correction made. NOTE — The air current can be produced by a blower fan
or from a perforated pipe supplied with compressed air. In
NOTES the latter case a pipe 10 mm to 13 mm internal diameter,
perforated along one side with a row of holes ( 0.8 mm to
1 The functioning of the slip ring contacts should be 1.5 mm in diameter) should be fixed horizontally at the
checked periodically by observing that there is no back of the drum (i.e. between the top and bottom portions
change in the recorded temperature when the of the belt) 600 mm from the drum centre and in the same
apparatus is run without a test sample. horizontal plane, with the row of holes facing the drum.
Approximately 20 kPa air pressure is required at the pipe.
2 The modification of the drum friction test equipment
to give a more accurate measurement of the tempera- The actual air velocity should be measured by an
ture of the drum surface has been included in F-1.2. anemometer and should be checked at regular intervals.

14
 IS 3181 : 1992

All dimensions in millimetres.

FIG. 14 BALANCE WEIGHT LEVER FOR DRUM FRICTION TESTING APPARATUS

F-1.5 Anemometer F-4 PROCEDURE

F-4.1 General
An anemometer shall be available to measure
the velocity of air current to an accuracy of ± 5 %. Prior to each test, clean the surface of the hori-
zontal steel drum with emery cloth so as to
Where an extractor system is provided for the remove all traces of any rust or debris of
removal of fumes from the vicinity of the conveyor belting produced by carrying out
apparatus, the velocity of the air current previous tests. In the clean condition, the drum
through the system shall not exceed 0.5 m/s. is bright as judged by eye and smooth to the
touch. Ensure that the temperature of the
F-2 NUMBER OF TESTS drum does not exceed 30ºC.
F-4.2 Test in Still Air
On belting which has the same thickness and
material of cover on both sides, four tests shall Pass the test piece through an arc of 180ºC
be carried out. Two of these tests shall be made around the stall drum. Ensure that the
in still air and the other two in moving air as horizontal end is rigidly secured and the free
described in F-4.2 and F-4.3 respectively. vertical end attached to the tensioning system
as shown in Fig. 14. After applying a tension of
With belting in which the thickness and/or the 343 N rotate the drum at 200 ± 5 rev/min away
material of one cover varies from that on the from the rigidly secured horizontal end of the
other side, eight tests shall be carried out. One test piece (i.e. similar to the forward direction
test in still air and one test in moving air shall of a conveyor drive) until the test piece breaks.
be carried out when each of the two covers are If the test piece has not broken after 60 min
in contact with the drum. Two further tests in increase the tensions as follows whilst the
still air and two further tests in moving air drum is still rotating:
shall be carried out with the cover which when, a) by 343 N to 686 N for further period of
it was next to the drum gave the worst result in 30 min.
the preliminary test. b) by 343 N to 1 029 N for further period of
30 min, if necessary.
F-3 PREPARATION OF TEST PIECE c) by 343 N to 1 372 N for further period of
10 min if necessary.
Cut the test pieces parallel to the belt edge, each d) by 343 N to 1 715 N the test being conti-
piece consisting of a rectangular strip of belting nued at 1 715 N until the test piece
150 mm wide and not less than 1.0 m long. breaks.

15
IS 3181 : 1992

Examine the test piece for any visible signs of F-4.3 Test in an Air Current
flame or glow during the test. After the test Carry out the test in accordance with F-4.2
piece has broken, leave the two pieces within using an air current as described in F-1.4.
the influence of the specified air current until
either flame or glow occurs or it is clear that The air supplied to the apparatus is at normal
niether is possible. ambient temperature, but do not make tests in
air at a temperature of less than 5ºC.
Record the surface temperature of the drum
during the test. F-5 TEST REPORT
NOTE — It may be necessary in the initial stages of a The following results shall be reported:
test, to reduce the tension in the sample by reducing the
force applied to the free end in order to prevent the a) The presence or absence of flame or glow
motor driving the drum from stalling. Such reductions in each test.
should be kept to the minimum possible and the full
initial tension of 343 N should be applied as evenly and
b) The maximum temperature of the surface
as quickly as possible. of the drum in each test.
c) The time for the test piece to break.

ANNEX G
( Clause 15.2 )

METHOD OF TEST FOR FIRE RESISTANCE (SPIRIT BURNER FLAME TEST)

G-1 APPARATUS G-1.4 Stop Watch

G-1.1 Burner
A stop watch with graduations of at least
A spirit burner ( see Fig. 15 ) fitted with a suit- 0.2 seconds or less. A stop watch with a 30 second
able device so that it can be moved away from the full sweep is suitable.
test piece without opening the door of the
cabinet. The supply of fuel is from a reservoir G-1.5 Band Facer
having a graduated side arm as shown in Fig. 16.
G-1.2 Fuel A mechanically driven band facer with a 60 grit
The burner is supplied with industrial aluminium oxide or silicon carbide band, not
methylated spirit. This spirit is an approximate less than 100 mm in width.
mixture of 5 percent by volume wood naphtha
(mainly methanol) and 95 percent of an G-2 PREPARATION OF TEST PIECES
ethanol/water mixture such that the relative
density of the spirit is 0.814 @ 20/20ºC.
Cut eight test pieces each 25 mm wide by
The fuel is free from suspended matter and 150 mm long clearly from the sample. Cut four
filtered before use. of the test pieces parallel to the length of the
belt and four at right angles to it. Cut the test
G-1.3 Cabinet pieces from places at a distance from each
The test shall be carried out in a cabinet to the other, so as to be representative of the whole
design and dimensions shown in Fig. 17. area of the sample of the belting.
The inside of the cabinet is black. The cabinet is
provided with an adjustable device to hold the Four of the test pieces comprising two cut in
test piece in position ( see Fig. 18 ). each direction are for tests with covers intact.
For other four test pieces (two cut in each
NOTES direction) remove the covers from the end to be
1 Additional close fitting hole may be made in the tested by buffing on the band facer in the
cabinet for the entry of the remote handling device of direction of the length of the test piece. Remove
the burner and the fuel pipe. at least 50 mm length of the covers. Cease
2 A fume hood with an extraction fan may be positioned buffing when all the knuckles of the fabric
above the cabinet, the fan may be run during the test become exposed. Only intermittent application
provided that it does not induce air movement through
the cabinet additional to that required for the operation
of the test piece to the band facer is needed to
of the burner. Where this condition is not satisfied, the minimise frictional heating. Avoid spreading a
fan is switched off during the test. layer of PVC over the knuckles of the fabric.

16
 IS 3181 : 1992

All dimensions in millimetres.

FIG. 15 SPIRIT BURNER

17
IS 3181 : 1992

d) During the testing, maintain the fuel level

in the reservoir within the range 760 ±
20 mm above the base of the burner.

G-4 PROCEDURE

Perform the tests in the cabinet in subdued light.

Light the burner and operate as described in G-3.
Insert the test piece into the holder, ensuring
that the test piece projects a minimum of 50 mm
beyond the edge of the holder. Adjust the holder
so that with the burner in the test position i.e.,
placed centrally on the base plate of the cabinet
the following conditions are satisfied:

a) The faces of the test piece are vertical,

the long edges horizontal, and the lower
edge 50 mm above the top of the burner
flame tube.
b) The test piece is located centrally in the
flame with, its front edge coincident
with the outer edge of the flame as given
in Fig. 19.
c) The test piece is normal to the door of
the test cabinet so that both faces can be
observed.

Bring the burner to the test position, and simul-

taneously start the stop watch and close the
cabinet door. After 30 seconds, move the burner
quickly but smoothly away from the sample to
the side of the cabinet using the remote handling
device. Record the time taken for all visible flame
or glow to disappear from any part of the test
piece after the withdrawal of the burner.
FIG. 16 RESERVOIR SIDE ARM
G-5 TEST REPORT
G-3 OPERATION OF THE BURNER
The following results shall be reported:
The burner is operated as follows:
a) With the control valve closed, check that a) The time for all visible flame or glow to
the fuel consumption is zero and then disappear on each of the six individual
heat the burner by burning fuel in the test pieces with covers intact.
primary heating cup. The average time for all visible flame or
b) Adjust the reservoir so that the fuel is glow to disappear on the six test pieces
760 ± 20 mm above the base of the with covers intact.
burner. Fully open the control valve at
least one turn and ignite the burner. b) The time for all visible flame or glow to
Allow the flame to stabilise for 10 min. disappear on each of the six individual
test pieces with covers removed.
c) Check the fuel consumption for at least
1 min while feeding the burner from the The average time for all visible flame or
graduated side arm with the main glow to disappear on the six test pieces
reservoir tap closed. During the with cover removed.
measurement check that the mean fuel
level in the side arm is 760 mm above the In the event that further samples are required
burner base. Ensure that the fuel to be tested as laid down in 15.2, the results of
consumption so measured is 2.55 ± these tests shall be reported additionally as in
0.15 ml/min. (a) or (b) above.

18
 IS 3181 : 1992

All dimensions in millimetres.

FIG. 17 CABINET FOR FLAME TEST

All dimensions in millimetres.

FIG. 18 TEST PIECE SUPPORT

19
IS 3181 : 1992

FIG. 19 LAYOUT OF SPIRIT BURNER FLAME TEST

ANNEX H
( Clause 15.3 )

PROPANE BURNER TEST

H-1 APPARATUS long, and form the frame on which the belt rests.
The upper surface of the bars shall be 350 mm
H-1.1 Gallery from the floor.
The test shall be carried out in an experimental H-1.3 Burner
gallery of square section, 2 m × 2 m, through
which air is drawn by a fan.
The burner, constructed in accordance with
H-1.2 Trestle Fig. 21, shall consist of a 450 mm square frame
having an overall height of 220 mm made of
The trestle shall be a framework of steel tubing welded steel tubing having an external diameter
having an external diameter 20-25 mm and is of 20-25 mm. The tubing shall have 52 holes 1.5 ±
2.20 m long × 1.25 m wide as shown in Fig. 20. 0.1 mm in diameter drilled at 50 mm intervals.
The upper sides of the trestle frame shall be
notched at 75 mm, 150 mm and multiples of 150 H-1.4 Fuel
mm from the burner end of the frame in order to
position and loosely retain fifteen 18/8 austenitic The burner shall be fed with bottled propane gas
chrome/nickel rust, acid and heat resisting steel of at least 95 percent and preferably 99 percent
bars. The bars shall be 10 mm diameter × 1.4 m purity through a pressure reducing valve and a

20
 IS 3181 : 1992

length of high pressure hose having a minimum H-2 SAMPLING OF MATERIAL

internal diameter of 6 mm. Before and during
the test, the gas cylinder shall be immersed to The length of the sample of belting with top and
approximately two-thirds of its height in a bath bottom covers of equal specified thickness shall
of water at a temperature of 25 ± 3ºC. The gas not be less than 4 m. For conveyor belting with
cylinder shall not be emptied at the end of a test top and bottom covers of unequal specified
by more than 90 percent of its gas weight thickness the length of the sample be not less
capacity. The weight of gas consumed during a than 6 m.
ten minutes test period shall be 1.30 ± 0.05 kg.
The width of the samples shall be 900 mm for
This may be achieved by controlling the gas
belt types 3, 4, 5 and 6. For belt types above
pressure at a standard orifice. A regulator is used
these the sample width shall be 1 050 mm.
to control the gas pressure at approximately
0.158 MPa when the orifice plate is 1.7 mm thick
with a hole 2.5 mm in diameter, which is fitted H-3 TEST PIECES
into the ‘handle’ of the burner as shown in Fig. 21.
A sensitive precision pressure gauge which has Full width rectangular test pieces each 2 m
been calibrated to ensure that the correct weight long shall be cut from the sample, two test
of gas is consumed, is used to monitor the pieces in the case of belting with covers of equal
pressure in front of the orifice plate. specified thickness, and three test pieces in the
Alternatively, the orifice plate and sensitive case of belting with covers of unequal specified
pressure gauge may be replaced by a flowmeter, thickness. The test pieces shall be laid out flat
calibrated to ensure that the correct weight of gas for 24 hours in dry conditions at any ambient
is consumed, inserted into the gas pipe line after temperature above 0ºC immediately prior to
the reducing valve. testing to remove residual curvature.

All dimensions in millimetres.

FIG. 20 PROPANE BURNER TRESTLE SHOWING POSITIONS OF BURNER AND TEST PIECE

21
IS 3181 : 1992

All dimensions in millimetres.

FIG. 21 PROPANE BURNER

H-4 TEST PROCEDURE H-4.4 The burner shall be placed centrally with
the four parallel burner tubes in line with the
H-4.1 The trestle shall be installed centrally on longitudinal axis of the piece, and positioned so
the longitudinal axis of the gallery with the that the distance from the top of the burner to the
burner end facing the direction of the ventilation top of the bars on which the belt rests is
flow. 130 ± 5 mm, with the transverse end row of
burner holes 50 mm inside the vertically
H-4.2 Each test piece in turn shall be placed projected transverse edge of the test piece.
centrally on the trestle with its transverse edge H-4.5 The burner shall be lit and the rate of gas
flush with the burner end of the trestle. In the consumption immediately adjusted as defined
case of belting with covers of unequal specified in H-1.4.
thickness, one test piece shall be tested with At the end of 10 minutes the gas shall be
the thicker cover facing upwards one with the switched off and the burner withdrawn from
thicker cover facing downwards and a third to under the trestle. This prevents molten and
provide a retest of the worst condition found in charred material from falling on to the burner
the previous two tests. This procedure is and blocking the holes.
necessary to ensure that the minimum two
samples are tested in identical conditions. H-4.6 The test piece shall be left on the trestle
until all flame and glow have disappeared.
H-4.3 The air current in the gallery shall be
adjusted to give an average velocity of 1.5 ± 0.1 H-5 MEASUREMENT OF DAMAGE TO
m/sec at a height of 350 mm. The measurement TEST PIECE
shall be taken on the centre line of the trestle and H-5.1 A measurement shall be made from the
at a distance of 750 mm upward of it. trailing edge on both the upper and lower

22
 IS 3181 : 1992

surfaces of the test piece of the length which The criteria for assessing damage to belting are
remains undamaged, not blistered or charred, listed below:
over its full width as shown in Fig. 22. a) Damage shall include any embrittlement,
hardening, cracking, blistering and other
blemishes not originally present.
b) Small blemishes, defined as blisters or
other damage having no dimension
greater than 5 mm, shall be dealt with
as follows:
i) In making the measurement of
belting left undamaged, up to 5 small
blemishes nearest the trailing edge of
the belting sample, can be regarded
as not being damaged.
FIG. 22 MEASUREMENT OF DAMAGE TO ii) Small blemishes more than 50 mm
TEST PIECE from each other and from any other
damage shall also not be regarded as
The measurement in each case shall be made in damage and shall be ignored.
a direction parallel to the longitudinal axis of iii) Any further small blemishes shall be
the belt. If the edges of the test piece are not formed into groups occupying regions
parallel because of uneven shrinkage, the of the belt surface which can be
direction of the longitudinal axis shall be enclosed within circles of up to 50 mm
judged by eye. The measurement shall be made diameter. The size and arrangement
along the surface of the test piece even if the of these regions shall be chosen in
test piece has become curved. such a way as to produce the most
favourable test result. Any one such
Care shall be taken to avoid confusing region shall not be regarded as
combustion damage with damage due to sooty changed and shall be ignored. Any
or greasy deposits and it may be necessary to additional regions shall not be regar-
remove these locally with a dry cloth in order to ded as damaged and shall be ignored
inspect the surface of the belt for combustion provided that such regions are
damage. Heat may cause a shiny surface to separated by at least 300 mm of
become matt but this should not be regarded as undamaged belt surface.
combustion damage.
H-6 EXPRESSION OF RESULTS
H-5.2 If failure of a test piece is due to its The two measurements made on each test piece
rolling up on itself towards the burner, the test of the length which remains undamaged over
shall be discontinued and a further test shall be its full width on the upper and lower surfaces
carried out in which the rear end of the test measured in accordance with H-5, shall be
piece is lightly wired to the trestle to restrain it recorded. The lower of the two measurements
from rolling up but shall not be so tightly bound made on each test piece defines the length of
as to prevent the small amount of a contraction full width belting remaining undamaged.
which normally takes place when the test piece The time for all flame or glow to disappear shall
is heated by the propane burner. be recorded.

23
Standard Mark
The use of the Standard Mark is governed by the provisions of the Bureau of Indian
Standards Act, 1986 and the Rules and Regulations made thereunder. The Standard Mark on
products covered by an Indian Standard conveys the assurance that they have been produced
to comply with the requirements of that standard under a well defined system of inspection,
testing and quality control which is devised and supervised by BIS and operated by the
producer. Standard marked products are also continuously checked by BIS for conformity to
that standard as a further safeguard. Details of conditions under which a licence for the use of
the Standard Mark may be granted to manufacturers or producers may be obtained from the
Bureau of Indian Standards.
Bureau of Indian Standards
BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promote
harmonious development of the activities of standardization, marking and quality certification of goods and
attending to connected matters in the country.

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implementing the standard, of necessary details, such as symbols and sizes, type or grade designations.
Enquiries relating to copyright be addressed to the Director (Publications), BIS.

Review of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are also
reviewed periodically; a standard along with amendments is reaffirmed when such review indicates that no
changes are needed; if the review indicates that changes are needed, it is taken up for revision. Users of
Indian Standards should ascertain that they are in possession of the latest amendments or edition by
referring to the latest issue of ‘BIS Catalogue’ and ‘Standards : Monthly Additions’.
This Indian Standard has been developed from Doc : No. LM 09 (4687) and amended by MGP 29.

Amendments Issued Since Publication

Amend No. Date of Issue
Amd. No. 1 May 2005

BUREAU OF INDIAN STANDARDS

Headquarters:
Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002. Telegrams: Manaksanstha
Telephones: 323 01 31, 323 33 75, 323 94 02 (Common to all offices)
Regional Offices: Telephone
Central : Manak Bhavan, 9 Bahadur Shah Zafar Marg 

323 76 17
NEW DELHI 110002  323 38 41
Eastern : 1/14 C. I. T. Scheme VII M, V. I. P. Road, Kankurgachi 

337 84 99, 337 85 61
KOLKATA 700054  337 86 26, 337 91 20
Northern : SCO 335-336, Sector 34-A, CHANDIGARH 160022  60 38 43

 60 20 25
Southern : C. I. T. Campus, IV Cross Road, CHENNAI 600113  235 02 16, 235 04 42

 235 15 19, 235 23 15
Western : Manakalaya, E9 MIDC, Marol, Andheri (East) 

832 92 95, 832 78 58
MUMBAI 400093  832 78 91, 832 78 92
Branches : A H M E D A B A D . B A N G A L O R E . B H O P A L . B H U B A N E S H W A R . C O I M B A T O R E .
FARIDABAD. GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR.
LUCKNOW. NAGPUR. NALAGARH. PATNA. PUNE. RAJKOT. THIRUVANANTHAPURAM.
VISHAKHAPATNAM.