Document 4vbMdGGZQ2MamyrErJwqnvwJe
UTEX 001143
Published by Klinger Internationsl Export Gee. m. b. H. on behalf of the companies of the Klinger Group. 1969 Klinger International. Vienna
UTEX 001144
ttLINGER
takes the guesswork out of gaskets
The new Klinger dimensioning method gives you quick solutions to many gasket problems . . .
Successful gasket design Involves three basic elements:
The right gasket material The right gasket dimensions The right gasket surface stress
Choosing the material Is usually straight forward since your Klinger catalogue gives recommendations for most common media. Getting the dimensions and stres ses right Is more difficult and In some cases requires the help of specialist gasket engineers, but there are plenty of everyday problems that you can solve without being a .gasket specialist, as this booklet shows.
(id
The data In this book have been com piled by ISTAG AG, central research organization of the Richard Klinger group of companies. They apply solely to the Klinger materials KLINGERIT , KLINGERIT4O0 UNIVERSAL and KLINGEROILIT.
UTEX 001145
Klingerit
A top quality sheet (or general use, composed of asbestos fibre with SBR binder. Used mainly on steam services but has excellent resistance to many oils and chemicals. Meets many UK, US and other specifications including BS 1632, BS 2815 A, DIN 3754 (It 400) and ASTM D 1170 Grade P.1161 A. Normally recom mended maxima: 550 C (1,000" F) and 1750 - 2,000 psl (120-140 atm).
Klingerit 400 Universal
A high temperature/high pressure sheet with outstanding resistance to oils, fuels and lubricants. Composed of asbestos with NBR binder. Has controlled low chloride content making It especially suitable for stainless steel flanges. Spe cification compliance Includes DTD 376 A, BS 2815 A, DIN 3754 (It C) and ASTM D.1170 Grade P.1141 A. Normally recom mended maxima: 550"C (1,000" F) and 2,000 psi (140 atm).
Klinger-Oilit
0A high pressure sheet with excell
resistance to hot oils, hydrocarbons etc. Composed of asbestos with NBR binder. Klinger-Oilit is widely used In the oil and chemical industries and meets BS2615A. DIN 3754 (It-Oe) and ASTM D.1170 Grade P. 1141 A. Normally recommended maxima: ca. 500" C (900" F) and 1.500 psi (100 atm).
UTEX 001146
How gaskets seal
^^nlmum surface stress at working pres sure)
If flange surfaces mated perfectly there would be no need for gaskets. In practice, Manges always have slight surface Irregularities, and a compres sible, resilient material -- the gasket -- is used to compensate for them. This provides an uninterrupted barrier against the medium and compensates for slight movement of the flanges during service. Even at low Internal pressures the gasket must be pressed against the flanges with a definite minimum surface stress. This "deformation stress" depends on the structure and compressibility of the gas( ^ material; for Kllngerlt, Kllngerlt 400 t^Pversal and Klinger-Oillt It Is
750 psi (50 kp/cm') for liquids 3,000 psi (200 kp/cm') for gases
At higher Internal pressure (p;) additional
gasket stress is necessary. This gives
a total minimum surface stress (pd ) at
working pressure:
m,n
(1) for liquids P0.min - 750 psi (50 kp/cm') + 2.5 p,*
(2) for gases p - 3,000 psi (200 kp/cm') + 4 p,
min
Values of pd calculated from these
min
formulae are given In Tables 3a and 3b (pages 13 and 14).
The factors 2.5 and 4 are generally called "gasket factors".
Note: Formula 1 also applies to many saturated vapours which condense at ambient temperatures. Formula 2 should be modified for highly toxic or dangerous gases by Increasing the gasket factor (to a maximum of about 8). With easily deformable flanges or where the available bolt load Is low, a softer material such as Klingertlex-A 10, Klingerflex-CB 1 or Kllngerpac may be advisable (low to moderate pressures only).
3
UTEX 001147
These formulae are not significantly de pendent on gasket thickness within the range 0.020" --(0.5-3 mm). There Is, however, a definite relationship between the degree of flange surface roughnesa and the minimum gasket thickness (see Table 1, page 12).
Table 3 (pages 13 and 14) gives values of Pdmln for various values of P). Use
Table 3a for liquids, 3b for gases. Inter mediate values can be interpolated.
1. Flng bolts provldo gaskst surface stress .
2. "Deformation stress' Is required even at zero In ternal presaure
1 Additional gasket streas Is needed to withstand Intarnal pressure
4
UTEX 001148
The hydrostatic end thrust (bursting thrust)
_ , hydrostatic snd thrust l.s. minimum assembly stress - p'dmln -Pm|n+ --^r8a of gasket
Hydrostatic end thrust - Internal pressure (p t) X internal area
For circular gaskets (ignoring bolt holes):
Minimum assembly stress
?/
+ Pi
where dt - Inside diameter
b - radial breadth
of gasket
Pd d_- mean (Sameter
(- di + W
Note that the hydrostatic end thrust Increases with the square ol the Inalde diameter.
In closed vessels the Internal pressure exerts a thrust on the cover or Hd -- the hydrostatic end thrust This applies also In closed pipelines, where the hy drostatic end thrust tends to pull the flanges apart This reduces the stress originally applied to the gasket (assembly stress).
The assembly stress must therefore: Compensate for the effect of the hydro static end thrust; (^J^l maintain the minimum gasket surface
stress needed to seal at working pressure
UTEX 001149
Choosing the right gasket thickness
Compreseed asbestos material* hav* a alight poroalty, so gaskets should be aa thin aa poaalbla. Thla raducaa dlffualon loaaaa and also the area exposed to attack by aggraaalv* madia (olla. chamlcala ate.).
Sine# tha gaakat muat companaata for tha auriaca roughness of tha flangaa, tha minimum thlcknaaa dapanda on:
Depth of flange auriaca roughnaaa Compressibility of tha gaakat Qaskat auriaca atreea rfl working presaura.
nessaa are given a* tha neareat stan dard Klinger sheets, so Inch and metric thicknesses do not correspond exactly. Thicker material* can of course be used but It I* technically beat as wall as economic to keep to tha minimum.
Turned flanges generally have peaked groove* which In affect reduca tha area of gaakat carrying tha flange load. This give* an Increased surface stress and Increased gasket compression. In such cases the gaakat thickness may be re duced to the values printed In BLUE (provided flanges are rigid and undistor ted).
Note: For Intermediate values of pd
us* the next THICKER gaskeL
"""
The minimum thickness la: 2 x maximum depth of flange surface rou ghnees x 100
compressibility (%) at given surface stress
Depth of flange surface roughness Is commonly expressed as a degree of sur face finish (v.cv ate.). Using this value and tha already calculated value of the minimum gasket thlcknaes can be taken from Table 1 (page 12) without further calculation.
The values given In Table 1 taka account of the roughness of both flange surfaces: as this Is not entirely necessary they contain a safety margin. Gasket thick-
UTEX 001150
Maximum gasket rsurface stress
-Minimum gasket area)
1. Use a larger gasket. This is only possible when the gasket dimen sions are not already fixed (e. g. by pipeline flange specifications such as BS, ASA, OIN etc).
2. Use a thinner material (and corre spondingly better flange finish).
Too high a gasket aurfaca atraaa can cause leakage. Thla la because the gas ket loses the resilience needed to main tain its pressure against the flange sur faces. The surface stress on the gasket must never exceed the recommended maximum.
For a given material the maximum per missible surface etress dependa mainly on the temperalure and the thickness. Thin materials withstand higher stresses than thick ones, cold conditions permit higher stresses than hot. For maximum permissible surface stress on Klinger materials see Tsble 2 (psge 12).
3. Use a material that withstands high er surface stresses a. g. wire-reinforced (Kllngerlt 1000) or spiral wound (Kllnger-Metallit). Maximum permis sible surface stress for Kllngerlt 1000 Is about 25 % above that of Kllngerlt, Kllngerlt 400 Universal and KlingerOlllt
This complication Is dealt with In Practi cal Example 2 (page 10).
With circular gaskets the minimum radial breadth can be found from Table 3 (pages 13 and 14). This table Is In four parts: liquid cold, liquid hot, gas odd and gas hot It gives the minimum radial breadth for various Internal pressurea as
*wM/d| -
If the ares enclosed by the gssket Is Example:
Isrge. the hydrostatic end thrust msy be Medium: hot gas
very large even at moderate internal Internal pressure: 1,500 pel (ca 100 atm)
pressure. This demands a correspondingly Inside diameter: 36in
high bolt loading and the calculated ml- Gasket thickness: Vu>n
#um assembly stress (- bolt load/area gasket) may exceed the permissible
For these data Table 3b (gas hot) gives
maximum for the given gasket thickness. W*. - 0.06
Thsrs are three possible remedies:
I. a. bmln - - d, x 0.06 - 1Jln
Note that the radial breadth of the gas ket should never be less than double the gasket thickness, to prevent the gasket from being crashed. For gases and other penetrating made the breadth should not be leaa than ftln (12 mm) or '/tin (0 mm) at vary least. This la to prevent diffusion of the medhim along the asbestos fibres.'
|
I
UTEX 001151
What prevents blow-out?
sfdering tha tensile strength at all: for this purpose tensile strength is Irrelevant
Gaskets are held In position by friction, not by their tantile strength. Thfa Is demonstrated by the following calcula tion.
Tha stability condition to resist blow-out Is that the frictional force exceeds the radial force caused by the Internal pres sure 1. a. frictional force > radial force 2ppd>(d| + b)b > pi*d|S
where /i -- 0.1 -- coefficient of static friction * a - thickness of gaakat
2x0.1 p e(d| + b)b> p|cd|S
5d|S d > * b (d, + b)
or Pd > P|
(It d la large compared to b.)
Pd In fact always exceeds 2A p| (formu lae 1 and 2, page 3). Also b Is never lass than 2 s, even In extreme cases. It follows that tha stability condition Is always fulfilled In a gasket assembly designed In accordance with the Klinger method. Only In the moat extreme ceaee Is e check-calculation of the frictional forces necessary. Note that the stability condition has been fulfilled without con-
* v Is In fact generally about 0.4; even with smooth flanges It is never lees than 0.1. Gaskets should never be treated with oil or grease since this reduces the frictional force. If a non stick material Is required, Klinger Jointinge can be supplied with graphlted surfaces.
fjl *
i
?
r r. ;
UTEX 001152
Practical example no. 1
a#
`inis example shows how the Klinger
dimensioning method speeds up calcu lation.
Given
Pipeline diameter
: 5 In (nominal)
Flanges
: B. 8.10 Table R (raised face)
Inside dla. of gasket : 5*/ in *
Outside dla. of raised lece: 7 In *
(* laid down by BS10)
Flange finish
: vv (turned)
Medium
: Cold water
Working pressure
: 1,200 pel
Teat pressure
: 1,800 pal
Gasket material
: Kllngerlt
*'Required
Determine minimum gasket thickness and minimum assembly surface strees.
Step 1
Find the minimum surface stress required st teet pressure. Table 3a (liquids), co lumn 2, gives this as P dnu.n - 5,280 pal (ca. 370 kg/cm*)
Step 2 Find the minimum thickness from Table 1 (page 12) for flange finish vo and p --
5,250 psl. Since the value 5250 psl lies between two of the valuee given In the table use the next THICKER material I. a. 0.040 In (1 mm), using the black figures. Since however the flanges are turned, the lower valuee of Vii" or 0.75 mm (blue flguree) are permissible.
Step 2 Find the mlnlrpum aseembty streea. Aa shown on page 5 this Is given by the formula: minimum assembly surface stress
1
- pa__ + pi rsar
Note: b - radial breath - % (outside dla - Inside dla)
d_ - mean diameter - (Inside dla. + b)
Hence minimum assembly surface stress - 5280 + 2270 psl - 7220 pel (ca. 565 kg/cm*)
Check
It is essential to check that the calcula ted minimum assembly surface stress does not exceed the maximum permis sible stress for material of the selected thickness. Table 2 (page 12) shows that the maximum permissible surface stress (cold) on 0.040 in Kllngerlt la 20,000 pel (ca. 1,400 kp/cm*). This Is well above the calculated mlnumum assembly stress of 7,820 psl so the design Is acceptable.
The actual assembly stress (and hence the surface stress under working pres sure) le normally chosen In excess of the minimum value and In such cases this higher stress must be checked against the permissible maximum.
Practical Example No. 2 deals with a case In which the calculated minimum etreee exceeds the permissible maximum.
UTEX 001153
Practical example no. 2
Thla example introduces the complication of a largo hydrostatic and thrust.
Qhren
A pressure vessel Is being designed as
follows --
Internal diameter
1,000 mm
The cover Is attached by flanges hav
ing a raised face (gasket seating face)
of radial breadth 20 mm. This surface
will be milled lo a finish of 7. Medium
Is cold gat, internal pressure (p() -
10 80 atm (ca 1,160 pal).
Minimum gaaket thickness and minimum aaaembly strata,
Slap 1 Using Table 3b (gas) tha minimum sur face stress at working pressure is found to be pd - 520 kp/cm*
Slop 2 For minimum stress at working pressure Pw - 520 kp/cm1 and flange finish -
7, Table 1 gives minimum gasket thick
ness - 3 mm.
Step 3 Minimum assembly stress
- pd-h, + Pi 4 bd - 520 + 960 - ca 1,500 kp/cm*
Check Table 2 shows that for 3 mm material the maximum permissible surface stress is 800 kp/cm* (cold). Snoe the calcula ted minimum assembly surface stress Is higher than the permissible maximum tha design Is not acceptable. The poeslble remedies are new considered in turn:
Larger gasket
It the vessel Is still at the design stage this may be possible. To determine minimum radial breadth required Table 3b (cold gas). For 3 mm gasket thickness and pt - 80 atm this gives
>Wi " 020 I.e. bmta- 1,000 x 0.20 - 200 mm If an even broader gasket Is used, a further check must be made that the resulting stress at working pressure does not fall below the required minimum.
'
Thinner gaaket
In this example the aimplest remedy would be to use smoother flanges and a thinner gasket capable of withstanding a higher surface atresa. Suppose the flanges are now machined to 77. Table 1 shows that the minimum gasket thickness Is now 0.75 mm. This material can accept surface streaaea up to 1,600 kp/cm* (cold) so the gasket design Is now satisfactory.
Other materials
Klinger gasket engineers will gladly gl advice In cases where neither of the above remedies proves practicable.
UTEX 001154
General notes
(^Lskat assemblies depend on many (ac
tors that are outside the control of the gasket manufacturer. These recommen dations are therefore a guide -- not s guarantee of success. Here are some other factors to consider.
Pipe expansions / contractions
Thermal expansions of the pipeline ge nerate forces which can crush the gas ket Contractions can reduce the gasket surface stress below the minimum re quired for sealing. Pipe expansions and contractions must therefore be compen sated by suitable expansion devices.
Flanges
These should be even parallel and suffi ciently rigid not to be distorted by the bolt load. The bolts should be tightened (preferably with a torque spanner) work ing at diametrically opposite nuts alter nately. First turn all bolts to about halt Ihe recommended torque, then follow up to full assembly torque. Follow up the bolts about 4 hours later or 1 hour after the gasket reaches its working temperature.
Flange finish
Concentric grooving Is Ideal for high pressures. "Gramophone" finish (spiral Grooving) gives a continuous path for Wakage and Is not recommended, espe cially for gases. A finish equivalent to vv Is usually best for flat surfaces.
,
11
UTEX 001155
Table 1
Minimum gasket thickness lor various surfaca straasaa (at working pressure) and dagraaa ol flango finish. For Intermadlata auriaca atrasa valuas uaa tha naxt THICKER matarlal.
Ip - 0.001mm - 0.04/1,000Inch
Valuas ara rounded upwards to naarast Kllngar standard ahaats, hanca Inch and matrlc thlcknetaas do not correspond exactly.
For Intermediate auriaca finishes (a. g. 100 p). minimum gaakat thickness may be Interpolated.
Surface Stress at Working Pressure
pal kp/cm*
Milled. Turrted etc. W- 180/1)
Inch mm
Ground, Tunited etc. VV(- 40 p)
Inch mm
Ground/Turned
vw(- 18f>0fy
Inch mm
1,400 2,800 7,000
100 200 500
10,500 750 14,000 1,000
Vs V.
v V.
v. '/,
52 42 3 1.5
'In 0.040 0.040 ./,,
V 'In
I V,I 0.040
1.5 0JJ2D 0020 1 0.020
1-5 1 1 0.75 0.75 075
0.75 A. 05 "
0.5
0.020 % 'It,
0.5 0* 04
'It, 04 0.008 04
TURNED flanges generally have peaked grooves which In effect reduce the area of gasket carrying the flange load. This gives an Increased surface stress and increased gasket compression. In such cases the gasket thickness may be reduced to the values printed In BLUE (provided flanges are rigid and undistorted).
Table 2
Maximum permissible auriaca stress
Thickness Inch mm
0420
'/ 0440
V.
-
V.
04 0.75
1
14 2 3
cold pal kp/cm*
28400 23,000 20400
15400 13400 8400
2400 1,800 1.400
1,100 000 800
300C pel kgfam*
20400 15,000 13400
10400 $500 5,500
1400 i,k
050 780 ^
800 400
UTEX 001156
Table 3 a (liquids)
<r Pd_
psl kp/cm*
pel kp/cm*
Minimum ratio radial width / Inalda die. of gasket
COLD Thlcknaaa
HOT Thlcknaaa
'/.' - /.'
'/' 0.08'
3 mm 2 mm 1,5 mml mm 0,75 mm 0,5 mm
V,' - V..' 0.W' V..' 0.08' 3mm 2mm 1,5mm 1 mm0,75mm03mm
ISO 300 575
850 1150 1450
1700 2000 2275
2550 2850 3125
3400 3700 4000
4300 4600 4900
6100 5700 8300
8000 7400
9 7900 8600
10 20 40
80 60 100
120 140 180
180 200 220
240 280 280
300 320 340
380 400 440
480 820 580
800
1.100 1.500 2X00
2.900 3.800 4.400
5.000 5.750 8.480
7.100 7X00 8X60_
~ 9X60
10.000
10.750
11X00 12X80 13X00
13X00 15.000 18X00
18X00 19X80 20X00
22X00
75 100 150
200 250 300
400 450
800 860 800
860 700 750
800 850 900
960 1060 1180
1280 1380 1480
1880
0.01 0.01 0X71 0X1 0X1 0.01 0.01 0.01 0-01 oxi oxi aoi 0.08 0.01 0X1 oxi oxi oxi 0.04 oxe o.oe 0.01 0X1 0X1 0X8 0X2 0X2 0.02 0X2 0.01 0X8 0X4 0X3 0.08 0X8 aoi
0.11 0X5 0.04 0X3 0X8 0.02 0.15 0X8 005 0.03 0X3 002 0X2 0X8 0X8 0.04 0X3 0.03
aio ox7 0X6 0X4 0X3 0.13 0X9 0.06 0X6 0X4 ai6 aio 0X7 0X6 0X4 0X0 ai2 0X8 006 0X6 0X8 au 009 0.07 0X6
ai7 aio 0X8 0X6
0X1 an 0.09 0X7 0X8 ai3 o.io 0X7
ais an 0X8
ai7 ais 0X9 0X3 ais aio
0X1 ai2
0X7 ai4 0.18 0X1
0X8
0X1 0.01 0X1 oxi aoi aoi ox2 oxi aoi 0X1 0X1 0X1 0X4 0X8 0.02 0X1 0X1 0X1
0X7 0.04 0X3 0.02 0X2 6.01 ai2 0X6 0X4 0.03 oxe 002 0X0 0X8 0X5 0.04 0X3 a08
0.11 0.08 0.06 0.04 0.03 0.15 0.00 0.06 0.06 0 03 0X2 0.12 0.08 0.06 0.04
0.16 0.09 0.07 0.05 0X1 0.11 0.09 0.08 0X9 0.14 0.10 0.07
0.17 ai2 0.06 0X1 ai5 0.09 0X7 0.18 0.10
oif aii oxe ais ________ t 0.16
0.17 0X3
Notea: Intermediate values should be Interpolated. The radial width of the gasket should never be lees than twice the thickness 13
UTEX 001157
Table 3 b (gases)
P) P4ta_in
pal
ISO 300 375
450 525 575
710 550 1000
1150 1300 1450
1500 1700 1550
2000 2150 2275
2560 2050 3125
3400 3550 3700
4000 4300 4000
4000 5100 5400
kp/cm*
10 20 25
30 35 40
60 50 70
SO 00 100
110 120 130
140 ISO 100
100 200 220
240 250 200
250 300 320
340 300 300
P*
3.000 4.200 4.500
4.000 5.100 5200
5.050 0.400 7.000
7.000 0.200 0.000
9.400 0300 10.400
11.000 11.000 12.100
13200 14.400 15300
13000 17200 17300
19300 O 21.400
22300 23.400 24.000
atm
240 280 300
320 340 360
400 440 480
520 560 000
040 000 720
700 000 040
920 1000 1000
1100 1200 1240
1320 1400 1480
1500 1040 1720
Minimum ratio radial width / Inalda dia. of gaakat
COLD
HOT
Thlcknaaa
Thlcknaaa
V
0.04'
0.02'
3mm 2 mm 1,5 mm 1 mm 0,75 mm 0,5 mm
-- 034' '/' 0.02' 3 mm 2 mm 1,5 mm 1 mm 0,75 mm 0.5 mm
0.01 0.01 031 0.01 301 0.01 0.02 0.01 301 0.01 031 0.01 0.02 031 031 031 *031 0.01 0.03 032 30T 0.01 0.01 "631 0.03 0.02 0.01 301 031 0.01 034 032 0.01 0.01 0.01 0.01
030 033 032 301 031 "531 0.09 033 302 302 301 0.01 313 034 0.03 032 302 031
020 0.0& 303~ '6.02 362 6.02 0.00 0.04 0.03 032 032 0.08 0.06 033 303 0.02
0.09 0.66 034 0.63 "358 0.11 0.07 0.04 303 032 0.14 030 030 304 033 021 310 636 0.04 "533 030 312 0.00 036 0.03
314 337 305 033 "021 "539"TEST""534
311 036 305 315 310 0.00
TOT- 312 537 325 314 300 310 038
TESTTTi6 020 312
314
TEl7 021 027
0.01 0.01 031 031 031 0.01 0.02 0.01 0.01 031 0.01 0.01 0.00 302 0.01 0.01 031 0.01
0.09 0.03 0.02 0.01 301 0.01 0.13 0.03 0.02 001 0.01 0.01 020 0.04 0.03 032 0.02 0.01
0.06 0.03 0.02 302 0.01 039 0.04 0.03 0.02 0.02 0.13 0.06 0.04 0.03 0.02
0.20 0.06 0.05 0.03 032 0.11 0.06 0.04 0.03 0.15 0.07 0.05 0.03
-------- -
020 0.00 0.06 0.04 020 310 0.07 0.04
0.13 0.00 0.06
0.16 0.10 0.05 020 312 0.06 029 0.14 0.07
0.21 0.09
0.11 315
321 326
M
14 Noim: Intarmadlata vahiw ahould ba Intarpdatad. Tha radial width of tha gaakat ahould novar ba laaa than twlca the thlcknaaa
UTEX 001158
Some famous users of
KLINGER
sket materials
AUTOMOTIVE INDUSTRY
BSA Motor Cycles Ltd., England. Daimler-Benz AQ, Germany Fiat Concord S. A. I. C., Argentina Ford Motor Co. Ltd., England Hanomag-Henschel Fahrzeugwerke GmbH,
Germany Industrie Automotrlz Santa FA S. A.,
Argentina Norton Vllliers Ltd., England Reliant Motor Co. Ltd., England Rhelnstahl-Henschel AQ, Germany Rolls-Royce Ltd., England The Rover Company Limited, England Steyr-Oalmler-Puch A. G,, Austria \
AVIATION INDUSTRY
British Aircraft Corporation (Operating) Ltd.
Oeutsche Forschungs- und Versuchsanstalt fOr Luft- und Raumfahrt EV, Ger many (German Aero-space Research and Testing Centre)
Dlreccidn Naclonal de Fabricsclones a Investlgaclones Aeroniutlcas, Argentina
Rolls-Royce Ltd. (Engines) Derby, England
CHEMICAL * ALLIED INDUSTRIES
The Associated Octal Company LImlted,
Klinger gasket materials are used by
England
leading Industrial organizations In over Australian Synthetic Rubber Co. Ltd.
^ countries. We gratefully acknowledge mission to quote the names of the
BASF Badlsche Anllln- & Soda-Fabrfk AG, Germany
Internationally famous companies given Boehrlnger Mannheim GmbH, Germany
In the following list
British Celanese Ltd.
Chemisette Fabrik von Heyden AG, Ger many
Chemisette Werke HOIs AG, Germany
CIBA S. A, Switzerland
CompafUa Qulmica 8. A, Argentina
Destllerfas KBram Walker A Sons (Argen tina) S. A.
Deutsche Solvay-Werfce GmbH
Dlsta Products Ltd, England
Dow Chemical GmbH, Germany
Dunlop, Germany
Dunlop Rubber Australia Ltd.
Etabllssements Kuhlmann, Belgium
Farbwerke Hoechst AG. Germany
Hibernla-Chemle AG, Germany
Hoffmann-La Roche AG, Germany
Imperial Chemical Industries Ltd, England
Kall-Chemie AG, Germany Imperial Chemical Industries of Australia
& New Zealand Ltd.
Lever Brothers Pakistan Ltd.
Lonza A. G,' Switzerland
E. Merck AG, Germany
Messer-Grlesheim GmbH, Germany
Monsanto Chemicals (Australia) Ltd.
Montecatinl, Italy
Osterreichischs Stickstoffwerke A. G,
Austria
7
Pak-American Fertilizers Ltd, Pakistan
Pak Chemicals Ltd, Pakistan v
Procter A Gamble Ltd, England
Procter A Gamble GmbH, Germany
Rhodlaceta, France
Ruhrchemle AG, Germany
Scholven-Chemle AG, Germany
Solvay A Cla, Belgium
IS
UTEX 001159