AlllDO T'lSlBE

n / NBs

NBSIR 81-2312

MSHA Wick Test for Hydraulic

Fluids: A Preliminary Evaluation

Center for Fire Research

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

July 1981

Final Report

Sponsored in part by

U.S. Bureau of Mines

Pittsburgh, Pennsylvania 15213

QC

2QQ B Safety and Health Administration

delphia. West Virginia 26059

81-2312

1981

C.2

AtSOMAL BVB.KAV or MTArmARUM

nanAST

NBSIR 81-2312

«r ^ MSHA WICK TEST FOR HYDRAULIC

FLUIDS: A PRELIMINARY EVALUATION

AUG 1 n-- Ou

Joseph J. Loftus

Center for Fire Research

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

July 1981

Final Report

Sponsored in part by

U.S. Bureau of Mines

Pittsburgh, Pennsylvania 15213

and

Mine Safety and Health Administration

Triadelphia, West Virginia 26059

8 1981

6

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
]tI
TABLE OF CONTENTS

Page

LIST OF FIGURES iv

LIST OF TABLES iv

Abstract 1

1 . INTRODUCTION 1

2. TEST MATERIALS 2

3. WICK TEST 2 3.1 Bunsen Burner 4

3 . 2 Wick 6

3.3 Cycling Device 6

3.4 Sample Conditioning 8

3.5 Wick Test Results 8

4. ALTERNATIVE TEST METHODS 12

4.1 Hot Wire Coil Test 12

4.2 Sustained Flame Contact Test 14

4.3 Comparison of Test Methods 14

5. CONCLUSIONS 19

APPENDIX 2 3

iii

MSHA WICK TEST FOR HYDRAULIC FLUIDS : A PRELIMINARY EVALUATION

Joseph J. Loftus

Abstract

This report is an evaluation and analysis of "The

Test to Determine the Effect of Evaporation on the

Flammability of Hydraulic Fluids (Wick Test) . " The Wick

Test is used by the Mine Safety and Health Administration

(MSHA) to qualify hydraulic fluids for use in underground

coal mines. This report includes a review of the test

method's operating characteristics as well as a comparison

of test results from the Wick Test with two alternative

test procedures—a hot wire coil test and a sustained flame

contact test. The evaluation program included currently

used fluids such as invert emulsions, synthetics, and water

glycols. The Wick Test studies showed that the test method

was not well defined and that reproducibility was poor.

The repeatability of the Wick Test could be improved by

using a sustained flame contact.

Key words: Coal mines, hydraulic fluids; ignition;

flammability; wick test.

1 . INTRODUCTION

The Code of Federal Regulations, Schedule 30, Part 35, outlines three

flammability test methods for hydraulic fluids. The Mine Safety and Health

Administration (MSHA) employs these test methods to qualify hydraulic fluids

as acceptable for use in underground coal mining operations for unattended

equipment or for attended equipment lacking fire suppression systems.

Acceptable fluids must meet all of the flammability requirements of the three

test methods. These test methods are:

• Test to Determine the Effect of Evaporation on the Flammability of

Hydraulic Fluids (Wick Test)

;

1
• Autogenous Ignition Temperature Test;

• Temperature-Pressure Spray Ignition Test.

In order to improve the operating characteristics of these tests, MSHA

requested the Center for Fire Research at the National Bureau of Standards to

conduct an evaluation of all three test methods. The following is a report

on an evaluation and analysis of "The Test to Determine the Effect of

Evaporation on the Flammability of Hydraulic Fluids (Wick Test) . " This report

includes a review of the test method's operating characteristics as well as a comparison of test results from the Wick Test with two alternative test procedures—one a hot wire coil test and the other a sustained flame contact test.

This report does not include an evaluation of whether the Wick Test is

appropriate or necessary to provide fire safe hydraulic fluids for underground

coal mines. Final recommendations concerning the need for the Wick Test will

be deferred to a subsequent report detailing an overall fire test program for

hydraulic fluids used in underground coal mines.

2 . TEST MATERIALS

A total of 14 different hydraulic fluids were selected for test. The

fluids were obtained from manufacturers who normally supply these materials

to the underground coal mining industry and who report that the fluids are

fire resistant under the Code of Federal Regulations, Schedule 30, Part 35;

i.e., meet the requirements of all three test methods. Included were two

water glycols, seven synthetics, and five invert emulsions. Water glycols

consist of a water-glycol solution with at least 35 percent water, synthetics

are fluids which contain organic esters; e.g., phosphates, or synthesized

hydrocarbons, and invert emulsions are hydraulic fluids that consist of a water and oil emulsion in which the water content may vary from 40 to 95

percent. Table 1 lists the fluid types and the specific gravities measured

for each of the test materials.

3. WICK TEST

The Wick Test is used by MSHA to determine the effect of evaporation on

the flammability of hydraulic fluids. Detailed operating procedures are contained in the appendix to this report. Briefly, this test measures the fire

resistance of hydraulic fluids by cycling fluid soaked wicks (i.e., pipe

2
Table 1. Test materials

Hydraulic Fluid Type No. Specific Gravity

g/cu cm

Invert Emulsions 5 0.92

7 0.94

11 0.91

13 0.93

14 0.92

Water Glycols 1 1.08

2 1.06

Synthetics 3 0.99

4 1.14

6 1.14

8 1.20

9 1.13

10 1.15

12 1.14

3
cleaner stems) into a bunsen burner flame. The number of cycles to ignition

of the wick is counted. Fluids are tested at three different conditions—as

received and after heating in an oven at 65°C for 2 and 4 hours, respectively.

The Wick Test criteria specify that hydraulic fluid samples must resist ignition for a minimum number of cycles at all three test conditions. The minimum

acceptable performance as listed in table 2 varies with sample conditioning,

it is lowest for samples conditioned for 4 hours and highest for samples as received.

3.1 Bunsen Burner

The Code of Federal Regulations state that "a standard (bunsen or

equivalent) laboratory burner" should be used as the ignition source in the

Wick Test. Three general types of bunsen burners were found that meet this

general description and these are described in table 3. The burners differ

only in orifice size and the presence or absence of a flame arrestor.

Observations made by the Center for Fire Research at the MSHA

laboratories showed that the bunsen burner used by MSHA had a barrel length

of 14.8 cm (5.9 in) with an inside diameter of 1.3 cm (0.5 in). The burner

had no flame arrestor and had an orifice plate of 1.93 mm (.076 in) aperture.

These dimensions correspond to the artificial burner described in table 3.

The burner flame height was measured at approximately 15 cm (6 in) and

the flame temperature at the Wick Test location showed a value of 835 °C. It

was noted that MSHA uses commercial grade methane (96 percent methane) for the

Wick Test. [Note: The Wick Test does not specify the type of gas to be used

for test but does call for a nonluminous flame of about 10 cm (4 in) in

height.

]

The Center for Fire Research conducted a study to determine the effects

of variations in burner orifice size on flame temperature. For test, four

methane gas flow rates ranging from 1274 to 1840 cc/min were used with three

different burner types and flame temperatures were measured with a shielded

type J (chromel alumel) thermocouple located in the flame at the Wick Test

location. The results of these tests listed in table 4 show that there are

almost negligible differences between the 1.02 and 0.79 mm orifices. The

1.93 mm orifice produced considerably higher flame temperatures for gas flow

rates in the 1274 cc/min to 1652 cc/min range. At 1840 cc/min, the flame

temperatures recorded for all three orifice plates were approximately the

same, 789 °C to 809 °C. Table 4 also shows that, for the fixed thermocouple

location, recorded temperatures decrease with increasing gas flow rates.

4
Table 2. MSHA wick test acceptance criteria

Sample Conditioning Minimum Number of Cycles

As received

2 hrs. at 65°C

4 hrs. at 65°C

25

18

12

Table 3. Description of three types of bunsen burners meeting

the general requirements of CFR schedule 30:35.22

Type Orifice Flame Arrestor

L . P . Ga s 0.79 mm ( .031 in) Yes

Natural Gas 1.02 mm (.040 in) Yes

Artificial Gas 1.93 mm (.076 in) No

Table 4. Effect of orifice size on the flame

temperature of a bunsen burner

Flame Temperature (°C)

Flow Rate

(cc/min) 1 . 93 mm 1 . 02 mm 0.79 mm

1274 960 835 840

1463 928 837 828

1652 906 815 821

1840 790 789 809

5
The relationship between gas flow rate, ignition of a fluid soaked wick

and flame temperature was determined in tests on one invert emulsion fluid

(no. 5) exposed to a flame from the artificial gas burner. In these tests

the rate of flow was monitored over a range of 1368 to 1841 cc/min. Table 5

indicates that there is no correlation between the number of cycles to ignition and the gas flow rate. The minimum number of cycles to ignition occurs

at gas flows between 1463 to 1746 cc/min and within this range the actual gas

flow rate was not critical.

3.2 Wick

The wicks (used for test) , are described in the Code of Federal

Regulations as being "ordinary, smoker's pipe cleaners (U.S. Tobacco Company,

Dill's, or equivalent)." "Dill" pipe cleaner stems measure approximately

15 cm (6 in) in length and contain white cotton fibers with a base wire thickness of 0.8 to 0.9 mm. The wick's combustible content was determined by taking

weights before and after burning all of the wicking material away from the

wire stem. In this way, the combustible content was found to be 0.01 ± .004

g/cm.

3.3 Cycling Device

MSHA uses a windshield wiper mechanism for cycling fluid soaked wicks

into the test burner flame. The cycling rate for test is specified at 25

cycles per minute.

CFR reproduced this test apparatus in the laboratory and made some

elementary measurements; for example, dry wick samples ignited in less than

four cycles and kerosene wicks in one cycle. The residence time for a wick

in the burner flame was 0.12 sec/cycle and for a 25 cycle exposure it was

estimated that a wick would spend a total of 3 seconds in the burner flame.

Table 6 compares CFR and MSHA Wick Test results on essentially the same

types of hydraulic fluid materials. [Note: The MSHA test data is old data

obtained by CFR in a survey of MSHA's records dating back a number of years.]

The MSHA data shows lower cycle counts to ignition than does CFR for all but

one of the fluids (no. 1 after 2 and 4 hours in the oven)

.

Synthetic fluids were not ignited in the NBS Wick Tests while MSHA's

tests showed ignitions for similar type fluids within 21 to 26 cycles of the

wick. Because of the discrepancy between results obtained in the two laboratories, especially for synthetic hydraulic fluids, the Center for Fire Research

6
Table 5. Relationship between gas flow rate, number of cycles to ignition

and flame temperature for fluid (no. 5) and 1.93 mm orifice

Number of Cycles

Flow Rate to Ignition Flame Temperature

(cc/min) (°C)

1368 60 940*

1463 52 928

1538 50 915*

1652 50 906

1746 47 840*

1841 58 790

1925 62 740*

* Interpolated flame temperature

Table 6. Comparison of MSHA and NBS wick test data

Number of Cycles to Ignition

0 time 2 hrs

.

4 hrs.

Fluid No. MSHA* NBS MSHA* NBS MSHA* NBS

7 37 55 36 47 34 41

13 36 66 30 75 35 60

4 26 N 23 N 23 N

9 23 N 22 N 21 N

12 26 N 23 N 22 N

1 50 92 34 14 16 10

* MSHA data obtained by the Center for Fire Research in a review of test results recorded over a period of time

7
conducted tests where the cycling rate of the wick was reduced to increase the

actual time a wick spent in the burner flame. Table 7 summarizes the data

obtained for tests on six synthetic fluids cycled at the rate of 15 cycles/

min. The fluids were tested in their as^received state.

An examination of these data shows that ignition propensity increased

when the cycling rate was decreased. However, even at this reduced rate,

fluid nos. 4, 9, and 12 performed better (longer cycle counts) in tests using

the Center for Fire Research's apparatus than the MSHA apparatus.

3.4 Sample Conditioning

Each hydraulic fluid must be evaluated under three different sets of

conditions (1) at room temperature (20°C) in their "as received" state, (2)

after 2 hours, and (3) after 4 hours of conditioning in a gravity convection

oven operated at 65®C (150°F) . Samples removed from the oven are allowed to

return to room temperature before testing.

3.5 Wick Test Results

Table 8 lists the results of NBS Wick Tests on 14 different hydraulic

fluids. The data indicate that the invert emulsion fluids easily met the

Wick Test acceptance criteria outlined in table 2. While the two water glycol

fluids performed very well in as-received tests, evaporations caused fluid

no. 1 to fail the 2 hour oven conditioning tests and fluid no. 2 samples to

fail after 4 hours conditioning.

Since evaporation of materials at 65°C (150°F) from fluid samples is the

primary objective of oven-conditioning, weight loss measurements were made for

the test fluids as a function of oven type. Two types of ovens in common use

are: (1) a forced air circulating oven which uses a blower to move heated air

through the oven chamber and out exhaust vents and (2) a nonforced air circulating or gravity convection oven which has no blower or exhaust vents.

Results of these evaporation experiments showed negligible weight losses

for the invert emulsion and synthetic hydraulic fluids; however, water glycol

fluids were found to lose approximately 40 weight percent after 4 hours in

either oven at 65 °C. Data for the water glycol fluids, table 9, shows small

differences between forced air circulating and convective oven samples.

Fluids (nos. 1 and 2) after 2 hours in the forced air circulating oven samples

lost more weight (2.3 and 6.2 percent more, respectively) than samples conditioned in the convective oven. Weight loss differences between the two ovens

8
Table 7. Effect of reduced cycling rate on ignition of

as received synthetic hydraulic fluids

Number of Cycles to Ignition

Fluid No. 15 cycles/min. 25 cycles/min.

4 50 N

6 32 N

8 40 N

9 41 N

10 52 N

12 84 N

N = Nonignition

9
*2

Table 8. Wick test results on hydraulic fluids

Number of Cycles to Ignition*

Hydraulic Fluid Type No . As Received 2 hrs . 4 hrs.

Invert Emulsions 5 52 52 44

7 55 47 41

11 47 35 30

13 66 75 60

14 38 47 45

Water Glycols 1 92 14 10

2 79 29 7

Synthetics 3 N N N

4 N N N

6 N N N

8 N N N

9 N N N

10 N N N

12 N N N

= Nonignition

Average: for five tests

10
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11
decreased for samples conditioned for 4 hours in the ovens. These weight loss

data showed that fluid no. 1 lost 0.4 percent more in the air circulating oven

and no. 2 lost an additional 1.4 percent in the same oven.

Wick tests were also performed on water glycol samples conditioned in

the two ovens. The data illustrated, table 9, show that the samples conditioned for 2 hours in the convective oven took longer to ignite (50 and 47

cycles) than samples conditioned for the same length of time in the forced

air circulating oven (14 and 29 cycles) . Comparable weight losses were

obtained for samples from both ovens conditioned for 4 hours. The number of

cycles to ignition was also comparable, but the forced air circulating oven

samples were still lower, 7 and 10 cycles, than the convective oven samples,

12 and 11 cycles, for fluid nos. 1 and 2, respectively.

4. ALTERNATIVE TEST METHODS

Two alternative test methods were developed for the evaluation of the

effects of evaporation on the flammability of hydraulic fluids. These tests

were developed with the aim of improving on the repeatability and reproducibility of the existing Wick Test method (see section 4.3). One was a hot wire

coil test that exposed fluid soaked wick samples to radiant and convective

heat. The other test exposed wick samples to sustained flame contact. Both

tests measured times (seconds) to ignition.

4.1 Hot Wire Coil Test

The hot wire coil test exposes fluid soaked wick samples [2.5 cm (1 in)

in length] to radiant and convective heat from an electrically heated wire

coil. The time (seconds) to ignition of the wick sample is recorded. The hot

wire coil test apparatus is shown in figure 1.

The coil is made of 16 turns of 22-gage nichrome resistance wire (3,301

ohm/m) with a diameter of 8 mm. The coil ends are attached to the tops of

2.5 cm (1 in) high ceramic posts which are attached to a plywood base. The

post centers are 5 cm apart. The top of the coil is flush with the top of

the posts. A wick holder made of aluminum rods and a wood base supports the

wick for test 4 mm above and central to the coil. The coil is powered by an

AC autotransformer adjusted to approximately 13 ± 1 volt and is calibrated for

test by using (kerosene) soaked wicks which ignited in 6.0 ± 0.2 seconds.

12
FIGURE 1.

HOT WIRE WICK TEST APPARATUS
Sample conditioning is the same as for the MSHA Wick Test. Table 10

lists the results of tests on 14 hydraulic fluids exposed to the hot wire coil.

As previously noted, the synthetic fluids did not ignite. The invert emulsions

increased their resistance to ignition after oven conditioning, while ignition

resistance of the water glycols decreased. After 2 hours in the oven, the

ignition times for the water glycols approached that of the kerosene wick

samples

.

4.2 Sustained Flame Contact Test

This test exposes fluid soaked wick samples to direct flame contact. The

test uses the same fluid sample preparation, wicks, artificial gas burner, and

methane gas (96 percent methane) as used for the MSHA Wick Test.

The burner flame height [10 cm (4 in)] is also similar. The bunsen burner

is mounted on a pivot that' allows for the easy movement of the burner from a 45

degree holding location to a vertical position (see figure 2) . 'When in a vertical position the distance from the burner top to the test wick (which traverses the burner flame diameter) is 7.5 cm (3 in)

.

For test, a fluid soaked wick is mounted horizontally in the wick holder,

the burner is moved to an upright position and a timer is started. The elapsed

time from the start of the test to ignition of the test wick is recorded.

Results of sustained flame contact tests on 14 hydraulic fluids are listed

in table 11. These data indicate that, for these test conditions, unconditioned

synthetic fluids ignited in the shortest amount of time followed by invert emulsions and water glycols. After conditioning in an oven for 2 hours, invert

emulsions produced slightly lower ignition times, while synthetics were not significantly affected. Water glycols, however, showed dramatic decreases in their

ability to resist ignition from 25 and 29 seconds to 3 seconds.

4.3 Comparison of Test Methods

A comparison of test results obtained by the three different test methods

(see table 12) shows that the sustained flame contact test was most severe on

synthetic fluids when tested in their original state, while the MSHA wick and

hot wire coil tests failed (with one exception) to produce ignitions for tests

on the synthetic fluid materials.

All test methods ranked the water glycol fluids slightly more resistant

to ignition than the invert emulsion fluid materials.

14
*z

Table 10. Results for hot wire coil tests on 14 hydraulic fluids

Fluid Conditioning

Hydraulic Fluid Type No. \s Received 2 hrs. @ 65'’C 4 hrs @ 65°C

(Time - Sec. to Ignition)

Invert Emulsions 5 30 34 42

7 30 51 49

11 29 50 55

13 28 61 56

14 43 60 63

Water Glycols 1 53 9 6

2 50 7 9

Synthetics 3 N N N

4 N N N

6 N N N

8 N N N

9 N N N

10 N N N

12 N N N

= Nonignition

Average: for five tests

15
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16
Table 11. Results for sustained flame contact

tests on 14 hydraulic fluids

Fluid Conditioning

Hydraulic Fluid Type No. 0-Time 2 hrs. 4 hrs

(Time - Sec . to Ignition)

Invert Emulsions 5 18 13 12

7 20 17 17

11 20 18 17

13 18 17 17

14 24 18 19

Water Glycols 1 25 3 3

2 29 3 2

Synthetics 3 6 6 6

4 8 7 6

6 10 7 8

8 8 9 10

9 8 7 8

10 10 6 5

12 7 6 6

* Average; for five tests

17
Table

12.

Results

of

tests

on

hydraulic

fluids

in

"as

received

condition"

by

three

different

test

procedures

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18

Estimated

total

exposure

time

-

(sec.)

for

wick

in

flame
Table 13 lists the results of tests for all three test methods when the

fluids were tested subsequent to oven conditioning. An examination of these

data shows that the water glycol fluids were the most susceptible to ignition

by all of the test methods; however, the tests did not agree on the ranking

of the synthetic and invert emulsion fluids.

Table 14 lists the average number of cycles or times to ignition along

with the standard deviation for the invert emulsions and water glycol fluid

materials.

A comparison of the variance, which is the square of the standard

deviation, for the hot wire coil test to the Wick Test and the sustained flame

contact test to the Wick Test shows that in 18 of 21 cases, the variability

of the sustained flame contact test was less than the variability of the Wick

Test while 13 of 21 cases demonstrated that the variability of the Wick Test

was less than the hot wire coil test.

The greater variability of the test results in the Wick Test as compared

to the sustained flame contact test was due to the random nature of drop formations. Early cycling of the wick through the bunsen burner flame causes the

fluid to bubble on the wick. Droplets are formed from the bubbling fluid in

a random manner and these fall from the wick during that part of the cycle when

the wick is not in the burner flame. The wick re-enters the flame with less

fluid material on it and with repeated cycles either more bubbles are formed

or the wick ignites. The sustained flame contact test does not have this

problem.

5. CONCLUSIONS

The Center for Fire Research conducted an evaluation of the Code of

Federal Regulations, Schedule 30, Part 35, test (used by MSHA) to determine

the effect of evaporation on the flammability of hydraulic fluids. Based on

the results of its investigation the following conclusions are drawn.

• The test method does not clearly define the type of burner used in the

test. The orifice size of the burner is not specified.

• The type of gas used in the test is not identified.

• No procedures are provided for monitoring the gas flow to the burner.

19
Table

13.

Results

of

tests

on

hydraulic

fluids

conditioned

for 2

hours

and 4

hours

in

an

oven

at

65

°C

and

tested

by

three

different

test

procedures o

VO

00 lA VO z z z

20
Table 14. Comparison of the standard deviation (s) for three different wick test procedures

Wick Test Hot Wire Coil Sustained Flame Contact

Hydraulic

Fluid No. Time

(Oven)

Cycles* S Sec

(Time)

.* S

(Time)

Sec. * S

0 52 2.59 30 7.05 18 0.84

5 2 hrs. 52 8.37 34 4.60 13 1.52

4 hrs. 44 2.61 42 7.67 12 1.67

0 55 2.35 30 2.99 20 1.92

7 2 hrs. 47 4.44 51 1.64 17 1.34

4 hrs. 41 1.58 49 4.62 17 1.14

0 46 9.34 29 3.79 20 1.30

11 2 hrs. 35 4.12 50 3.51 18 1.14

4 hrs. 30 2.88 51 9.89 17 0.89

0 66 5.98 28 2.99 18 0.50

13 2 hrs. 75 4.55 61 10.01 17 1.10

4 hrs. 60 3.78 56 8.20 17 1.10

0 38 4.98 42 5.50 24 2.00

14 2 hrs. 47 2.30 60 2.50 18 1.30

4 hrs. 45 0.96 63 5.12 19 1.92

0 92 5.13 53 2.06 25 4.09

1 2 hrs. 14 0.71 9 1.14 3 0.00

4 hrs. 10 2.61 9 2.35 3 0.00

0 79 3.13 50 3.30 29 5.22

2 2 hrs. 29 5.03 7 1.64 3 0.71

4 hrs. 7 1.10 6 1.57 2 0.55

* Average for five tests each data cell

21
• The pipe cleaner stems (wicks) are not sufficiently described; e.g.,

the amount of combustible on the wick, etc.

• The distance of the wick to the top of the burner is not specified.

• The meaning of self-sustained flame is not clear (Note: A cycling

wick will sometimes ignite but then go out before it re-enters the burner

flame.). Some laboratories do not consider this an ignition.

• The repeatability of the Wick Test is hampered by the fact that fluid

droplets tend to fall off the wicks in a random manner during test and thus

fluid rich wicks would necessarily take more cycles to ignite. This may lead

to a wide spread in the number of cycles to ignition for a single fluid

material

.

• Since repeatability of the test may be poor in one laboratory, it is

likely that the reproducibility of the Wick Test between laboratories would

also be less than adequate.

• The sustained flame contact test should be considered by MSHA as a replacement to the Wick Test. This test provides the following advantages:

(1) the time the wick sample remains in the test flame is not variable as in

the case of cycling wicks in the MSHA Wick Test, (2) the problem of fluid

material falling or dropping off the wicks during test is eliminated, and (3)

the sustained flame contact test was found repeatable for tests on hydraulic

fluids in the laboratory and would most likely be found to produce reproducible

test results between laboratories.

22
APPENDIX

MSHA Wick Test to Determine the Effect of Evporation

on the Flammability of Hydraulic Fluids

(A) Test Apparatus

(1) Oven (gravity convection type) for conditioning fluid samples.

(2) Petri dishes 90 x 16 mm to contain samples for conditioning in the

oven.

(3) Wicks —pipe cleaner stems (Dill or equivalent)

.

(4) Bunsen burner fired with methane gas (96 ± 1 percent methane)

.

(5) Cycling device (electrically operated windshield wiper mechanism or

equivalent)

.

(B) Sample Preparation

A total of 15 wicks each 7.5 cm (3 in) long are required for test. Five

wicks are soaked in original state fluid, five in fluid conditioned for 2 hours

in an oven operated at a temperature of 65 °C (150 ®F) , and five in fluid conditioned for 4 hours at the same temperature. Each wick is soaked for at least

2 minutes and is allowed to drain for 1 minute before test.

(C) Test Procedure

The bunsen burner flame is ignited and adjusted to produce a 10 cm (4 in)

high nonluminous flame.

A prepared wick sample is mounted in the sample holder positioned at the

end of a 90 degree arc farthest away from the burner flame.

A test is started by cycling the wick sample into the burner flame (at

the rate of 25 ± 2 cycles per minute) and making a count of the number of times

the wick cycles into the burner flame without ignition. (Note; Ignition is

defined here as sustained flaming on a wick traveling away from and back into

the burner flame.)

23
Five tests are made for each fluid condition, i.e., original, 2 hour, and

4 hour oven conditioned samples.

(D) Test Criteria

A hydraulic fluid is classified as fire resistant by the MSHA Wick Test

if the following conditions were met:

(1) Original state fluid must cycle at least 25 times without ignition.

(2) Two hour samples must cycle at least 18 times without ignition.

(3) Four hour samples must cycle at least 12 times without ignition.

24
U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No.| 3. Publication Date BIBLIOGRAPHIC DATA

REPORT NO.

SHEET (See instructions) NBSIR 81-2312 July 1981

4. TITLE AND SUBTITLE

MSHA WICK TEST FOR HYDRAULIC FLUIDS; A PRELIMINARY EVALUATION

5. AUTHOR(S)

Joseph J. Loftus

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

S. Type of Report & Period Covered

Final Report

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

and U.S. Bureau of Mines

Pittsburgh, Pennsylvania 15213

Mine Safety and Health Administration

Triadelphia, West Virginia 26059

10.

SUPPLEMENTARY NOTES

Document describes a computer program; SF-135, FIPS Software Summary, Is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibiiography or literature survey, mention it here)

This report is an evaluation and analysis of "The Test to Determine the Effect of

Evaporation on the Flammability of Hydraulic Fluids (Wick Test)." The Wick Test

is used by the Mine Safety and Health Administration (MSHA) to qualify hydraulic

fluids for use in underground coal mines. This report includes a review of the

test method’s operating characteristics as well as a comparison of test results

from the Wick Test with two alternative test procedures—a hot wire coil test and

a sustained flame contact test. The evaluation program included currently used

fluids such as invert emulsions, synthetics, and water glycols. The Wick Test

studies showed that the test method was not well defined and that reproducibility

was poor.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

Coal mines; hydraulic fluids; ignition; flammability; wick test.

13.

AVAILABILITY

(y^ Uni imited

I I For Official Distribution. Do Not Release to NTIS

Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

[J^Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

28

15. Price

$6.50

USCOMM-DC 6043-P80
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