AlllOD

NBS

PUBLICATIONS

NAT'L INST. OF STAND & TECH

AlllOb M07E6M

NBSIR 81-2395

An Assessment of Three Different

Fire Resistance Tests for Hydraulic

Fluids

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washisngton, DC 20234

October 1 981

Final Report

Sponsored in part by;

I U.S. Bureau of Mines

Pittsburgh, Pennsylvania 15213

and

•QC—

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81-2395

line Safety and Health Administration

riadelphia. West Virginia 26059
i
MATIOMAL BW»BAO

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LIBRABT

NBSIR 81-2395

JAN 8 1982

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AN ASSESSMENT OF THREE DIFFERENT

FIRE RESISTANCE TESTS FOR HYDRAULIC

FLUIDS

no.

Joseph J. Loftus

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, DC 20234

October 1 981

Final Report

Sponsored in part by:

U.S. Bureau of Mines

Pittsburgh, Pennsylvania 15213

Mine Safety and Health Aditiinistration

Triadelphia, West Virginia 26059

and

O

(• Q

ry

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
t ^y .

.'S' ,•
TABLE OF CONTENTS

LIST OF TABLES

Abstract. . .

1. INTRODUCTION

2. FIRE TEST METHODS

2.1 Autogenous Ignition Temperature Test. . . 2.2 Temperature-Pressure Spray Ignition Test.

2.3 Effect of Evaporation on the Flammability

of Hydraulic Fluids (Wick Test)

3. TEST MATERIALS

4. TEST RESULTS

4.1 Autogenous Ignition Temperature Test. . . 4.2 Temperature-Pressure Spray Ignition Test.

4.3 Effect of Evaporation on the Flammability

of Hydraulic Fluids

5. TEST OBSERVATIONS

5.1 Autogenous Ignition Temperature Test. . . 5.2 Temperature Pressure Spray Ignition Test.

5.3 Effect of Evaporation on the Flammability

of Hydraulic Fluids

6 . RECOMMENDATIONS

6.1 Autogenous Ignition Temperature Test. . . 6.2 Temperature Pressure Spray Ignition Test.

6.3 Effect of Evaporation on the Flammability

of Hydraulic Fluids

7. CONCLUSIONS

8 . ACKNOWLEDGEMENTS

9 . REFERENCES . . . APPENDIX A. Autogeneous Ignition Temperature Test

for Hydraulic Fluids

APPENDIX B. Temperature Pressure Spray Ignition Test

for Flammability Resistance of Hydraulic

Fluids

APPENDIX C. Test for the Effect of Evaporation on the

Flammability of Hydraulic Fluids ....

Page

iv

1

1

2

2

2

3

3

4

45

5

6

6

6

7

8

8

9

10

10

12

13

14

20

iii

38
LIST OF TABLES

Page

Table 1. Autoignition Temperatures for Hydraulic Fluids 4 Table 2. Comparison of MSHA and NBS Wick Test Data 8

Table 3. Results of Spray Ignition Tests on Hydraulic

Fluids Using MSHA Test Procedures 11

XV
I . "'j

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An Assessment of Three Different Fire Resistance

( Tests for Hydraulic Fluids

Joseph J. Loftus

Abstract

Three different fire resistance tests for hydraulic

fluids were evaluated in tests on fourteen different

hydraulic fluid materials. Special emphasis was placed

on procedural details pertinent to the repeatability and

reproducibility of the tests. Recommendations for changes

in the test methods and procedures are made based on results in this evaluation study.

Key words: Autoignition temperature; coal mines; fire

resistance tests; fire tests; flammability; hydraulic

fluids; ignition.

The Center for Fire Research at the National Bureau of Standards (NBS)

,

at the request of the Mine Safety and Health Administration (MSHA) and the

Bureau of Mines (BOM) , made an evaluation or assessment of three different

flammability tests used by MSHA for measuring the fire resistance of hydraulic fluids intended for use in underground coal mining operations. The test

methods described in the Code of Federal Regulations Schedule 30, Part 35,

1. INTRODUCTION

1
are: an Autogenous Ignition Temperature Test, a Temperature-Pressure Spray

Ignition Test and a Test to Determine the Effect of Evaporation on the Flammability of Hydraulic Fluids.

This report summarizes the results of the evaluation studies and

includes recommendations for changes or improvements in the three different test procedures. Each of these test methods are discussed briefly in

section 2.

2. FIRE TEST METHODS

2.1 Autogenous Ignition Temperature Test

This test is used to determine the lowest temperature for ignition of a hydraulic fluid material. The method calls for injecting measured fluid

volumes from a hypodermic syringe into a preheated erlenmeyer flask mounted

in a heated tube furnace and observing the temperature at which the fine

fluid spray ignites in the flask. Tests are made for a number of different

temperatures until the minimum temperature and volume of fluid needed for

ignition are determined for the hydraulic fluid material.

2.2 Temperature-Pressure Spray Ignition Test

In this test a hydraulic fluid, under a pressure of 1030 KPa (150 psi)

and at a temperature of 65°C (150°F) is sprayed into each of three different

ignition sources: a flaming trough (cotton waste wetted with kerosine and

ignited), a propane torch flame and electric sparks. Observations for con- tinuous flaming are made. Any fluid which shows continuous flaming for 6 seconds or more fails to meet the fire resistant requirements of the test.

2
2.3 Effect of Evaporation on Flammability

of Hydraulic Fluids (Wick Test)

This test seeks to determine whether a hydraulic fluid on losing some

of its components, e.g., water, glycol, etc., as a result of use in mining

equipment, may become ignited when exposed to an open flame. In this test,

original and oven conditioned fluid specimens [2 and 4 hours in an oven

at 65°C (150°F)] are soaked into pipe cleaner wicks and the wicks are then

cycled into a bunsen burner flame until the wick is ignited. A count is

made of the number of times a wick cycles into the flame without igniting.

If the count meets or exceeds an established minimum number of cycles to

ignition, a fluid meets the wick test requirements.

3. TEST MATERIALS

A total of 14 different hydraulic fluids were selected for testing.

Included were two water glycols, seven synthetics and five invert emulsions. 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, Flammability Regulations.

Invert emulsions are hydraulic fluids that consist of oil in a water

emulsion in which the water content may vary from 40 to 95 percent.

Synthetics are fluids which contain organic esters, e.g., phosphates

or synthesized hydrocarbons, while water glycols consist of a water-glycol

solution with at least 35 percent water.

3
4 . TEST RESULTS

4.1 The Autogenous Ignition Temperature Test

Table 1 lists (AIT) temperatures and minimum fluid volumes for the

lowest ignition temperatures for the 14 different hydraulic fluids.

Fluid

No

Table 1. Autoignition

Type

Temperatures

Autoignition

for Hydraulic

Temperatures

Fluids

Min. Volume

Deg F Deg C cc

1 Water glycol 884 440 0.05

2 Water glycol 770 410 0.05

3 Synthetic 761 405 0.10

4 Synthetic 1013 545 0.03

5 Invert Emulsion 743 395 0.05

6 Synthetic 1013 545 0 . 07

7 Invert Emulsion 716 380 0.05

8 Synthetic - - -

9 Synthetic 932 500 0.10

10 Synthetic 1032 555 0.05

11 Invert Emulsion 702 375 0.05

12 Synthetic 1022 550 0.03

13 Invert Emulsion 752 400 0.05

14 Invert Emulsion 770 410 0.03

An examination of the above data shows that all of the test hydraulic

fluids easily passed the minimum allowed AIT level established by this test

at 315°C (600°F)

4
4.2 Temperature-Pressure Spray Ignition Test

Table 3 (see page 11) shows results for spray ignition tests on 14

different hydraulic fluids using the MSHA spray ignition testing procedures.

An examination of this table shows that 13 of the 14 fluids passed the

electric sparks test while 11 fluids failed every propane torch and

flaming trough test. Fluids no. 1, 2 and 3 water glycol, water glycol

and synthetic respectively were the only fluids found to pass all spray

ignition tests.

4.3 Effect of Evaporation on the Flammability

of Hydraulic Fluids

The MSHA wick test uses three different sets of test samples:

1. Original state - all 14 test fluids passed the wick test.

2. Two hour conditioned samples - all invert emulsion and synthetic

fluids passed all tests. Water glycol fluids failed the test.

3. Four hour conditioned samples - results duplicate (2) above.

Oven conditioning had no effect on the wick test performance of invert

emulsions and synthetic fluids simply because these fluids remained

unchanged (i.e., showed negligible weight loss) as a result of oven conditioning, and the fluid samples performed in the same manner as original

state fluids.

5
Oven conditioning had a considerable impact on the flammability of

water glycol fluids. These fluids last 30 to 40 percent of original sample

weight and the residual fluid materials were easily ignited in the wick

tests

.

5. TEST OBSERVATIONS

5.1 Autogenous Ignition Temperature Test

• The ,AIT test uses the same test apparatus and procedures as ASTM

Standard D-2155-66 Autoignition Temperature Test for Liquid Petroleum

Products

.

• The test was found to require an inordinate amount of time to conduct

because attainment of uniform temperatures in the test flask required numerous adjustments to three manually controlled heaters in the test apparatus.

• Much of the testing protocol useci in the (AIT) test appears to be

unnecessary since the objective of the test is simply to determine whether

a hydraulic fluid ignites at 315°C (600°F) or below.

• Repeatability of the AIT test was found excellent.

5.2 Temperature-Pressure Spray Ignition Test

• The electric sparks ignition source did not provide a severe test

for the hydraulic fluid types tested here.

6
• It appears unnecessary for the spray ignition test to require two

different open flame ignition sources (i.e., propane torch and flaming

trough) since each ignition source provided for identical test results.

• The MSHA Spray Ignition Test conditions of 65°C temperature, pressure

of 1030 Kpa, spray nozzle orifice diameter of 0.63 mm and spray nozzle to

ignition source distance of 45 cm were found to be appropriate for conducting spray ignition tests on hydraulic fluids.

Reproducibility of the test results; e.g., comparison of the

Center's test results with MSHA showed poor agreement. The Center showed

11 failures for 14 fluids. MSHA approved all 14 fluids for use in coal

mines

.

5.3 Effect of Evaporation on the Flammability

of Hydraulic Fluids

o Repeatability of the wick test was found poor in the NBS laboratory.

• Reproducibility of the wick test between laboratories was also

found poor as evidenced by a comparison of MSHA and NBS data for 6 of the

hydraulic fluids shown in table 2.

7
Table 2. Comparison of MSHA and NBS Wick Test Data

Oven Conditioning

0 hrs. 2 hrs. 4 hrs.

Number of Cycles to Ignition

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

results recorded over a period of time.

6. RECOMMENDATIONS

Recommendations for changes in each of the MSHA fire test methods based

on these evaluation test results are made here and these are included in

revised and rewritten versions of the MSHA testing procedures in appendicies A, B and C of this report.) Highlights of these changes are listed

in the following sections.

6.1 Autogenous Ignition Temperature Test

(For new procedure see appendix A.)

• Furnace air temperature - The furnace air temperature should be

maintained at one test temperature only: 315°C (600°F).

8
• All tests should be made at this temperature since the test criteria is satisfied when a hydraulic fluid does not ignite at this temperature

6.2 Temperature-Pressure Spray Ignition Test

(For new procedure see appendix B.)

• Spray ignition test nozzles should be calibrated and those having

tolerances of + 10 percent of the flow rate specified for the nozzles by

the spray test method should be used for test.

• System integrity - Before beginning tests a 0-200 psi pressure gage

should be substituted for the spray nozzle in the test apparatus and the

system pressurized (without fluid) to 150 + 5 psi. All tubing, hoses and

valve connections should be inspected for leaks and all necessary adjustments should be made to ensure that the spraying system will maintain its

pressurized integrity for testing.

• Ignition sources - The spacing between electrodes in the Electric

Spark Test should be 12.5 mm (0.5 in).

The propane torch nozzle orifice diameter should measure 2.5 + 0.25 mm

The flaming trough should be fueled with standard cotton cheesecloth

material (federal supply no. 8305-00-205-3496) . Fifty grams of material should be wetted with 50 cc of kerosine and

ignited for test.

• Heat losses - If metal tubing or other material used to transport

fuel to the spray nozzle is subject to heat losses it should be wrapped

in heating tape or other material to ensure that the fluid exits the

spray nozzle within 3°C of the specified test temperature.

9
6.3 Effect of Evaporation on the Flammability of

Hydraulic Fluids "Wick Test"

(For new procedure see appendix C.)

• The bunsen burner orifice should be specified. Recommend

1.25-1.60 mm (.06-. 08 in) diameter.

• Methane gas (96+1 percent methane) should be used.

• Gas flow to the burner should be monitored with a flowmeter

having a measurement range of 1130-1880 cc/min (.04-. 07 cu ft/min) .

• Gas flow for test should be 1440 cc/min.

• Wicks should be located 7.5 cm (3 in) from the top of the burner.

• Wicks (pipe cleaner stems) should have a wire thickness of

0.75-1.0 mm (.03-. 04 in) and have a combustible content of .015-. 025 g/in

of stem length.

7. CONCLUSIONS

The Autogenous Ignition Temperature Test produced repeatable

test results in the laboratory.

• Testing at one furnace temperature 315°C (600°F) appears to be

adequate for obtaining ignition temperature information by this test.

10
Table 3 . Results of spray ignition tests on hydraulic

fluids using MSHA test procedures

Fluid Ignition Source

No. Type

Torch

(Benzomatic)

Electric

Sparks

Flaming

Cotton

1 Water Glycol N N N

2 Water Glycol N N N

3 Synthetic N N N

4 Synthetic I N I

5 Invert Emulsion I N I

6 Synthetic I N I

7 Invert Emulsion I N I

8 Synthetic I N I

9 Synthetic I N I

10 Synthetic I I I

11 Invert Emulsion I N I

12 Synthetic I N I

13 Invert Emulsion I N I

14 Invert Emulsion I N I

N - Nonignition - Pass

I - Ignition - Failure

11
Temperature-Pressure Spray Ignition Test

• Reproducibility of the MSHA tests at NBS was poor.

• The propane torch test might easily be dropped from the MSHA

test procedures without reducing the severity of the spray ignition

test, since the flaming trough test produces identical test results.

• From a safety viewpoint the flaming trough test is preferred

over the propane torch ignition source because it is easier to control,

reproduce, and is safer to operate.

• The electric spark test does not provide a severe ignition source

for hydraulic fluid spray tests.

The Effect of Evaporation on the Flammability of Hydraulic Fluids

• This wick test showed poor repeatability in laboratory tests and

poor reproducibility between MSHA and NBS test results.

• The test is severe on water glycols but had no effect on fluids

which did not lose weight on oven conditioning; synthetics and invert

emulsions

.

8 . ACKNOWLEDGEMENTS

Thanks are due to the following co-op Student Assistants whose considerable contributions helped to complete these evaluation studies: R. Torres,

J. Simenauer, E. Ruiz, A. Maldonado, N. Juarez, and P. Allen.

12
9. REFERENCES

[1] Loftus, J. J. , Juarez, N. , Maldonado, A., and Simenauer, J.,

Flammability measurements on fourteen different hydraulic fluids

using a temperature--pressure spray ignition test, Nat. Bur. Stand.

(U.S.), NBSIR 81-2247 (March 1981).

[2] Loftus, J.J., MSHA wick test for hydraulic fluids: A preliminary

evaluation, Nat. Bur. Stand. (U.S.), NBSIR 81-2312 (July 1981).

[3] Loftus, J.J., Allen, P., Maldonaldo, A., An Evaluation of the MSHA

Temperature-Pressure Spray Ignition Test for Hydraulic Fluids, Nat.

Bur. Stand. (U.S.) NBSIR 81-2373 (September 1981).

13
APPENDIX A

Autogenous Ignition Temperature Test for Hydraulic Fluids

.1 Scope and application.

The Code of Federal Regulations, Title 30, Part 35, lists three

different tests for measuring the flammability resistance of hydraulic

fluids

• Temperature—pressure spray ignition test;

• Autogenous ignition temperature test;

• Test to determine the effect of evaporation on flammability

of hydraulic fluids.

Candidate hydraulic fluids which meet all the flammability

requirements of these tests are considered acceptable for use in

all underground coal mining operations.

Under Title 30, flammability resistant hydraulic fluids must be

used in the following mining operations:

(a) Where electrically powered equipment is used in attended

operations but where no fire suppression equipment is readily

available.

(b) Where electrically powered equipment is used in unattended

operations

14
The following, provides procedures for test no. 2, The Autogenous

Ignition Temperature Test" for hydraulic fluids.

.2 Definitions.

(a) Attended operations . Under Title 30, Chapter 1, Mining

Enforcement Safety Admin Sec 75.1107-1 (A-D) , attended operations

means (1) any machine or device which is regularly operated by a miner

and (2) any machine or device which is in direct line of sight of a job

site and within 500 feet of a miner working the job site.

(b) Unattended operations means all operations not covered by

the above definition for attended operations.

(c) Fire suppression equipment means any equipment capable of

discharging a fire extinguishing medium such as dry powder or other type

of material in sufficient quantity on a fire to bring it under control

and to extinguish it.

(d) Hydraulic fluid means any fluid which is used under pressurized

conditions to operate mining machines or devices.

(e) Fire resistant hydraulic fluid means any (d) fluid which meets

all requirements of the three tests cited in .1 Scope and application.

15
.3 Summary of test.

Small sample volumes of hydraulic fluid (<1 cc) , are sprayed or

injected by a hypodermic syringe into an electric heated tube furnace

operated and maintained at a temperature of 351°C (600°F) to determine

whether a fluid ignites or resists ignition at this specified temperature .

(a) Tes.t criteria . An hydraulic fluid meets the requirements

of the "Autogenous Ignition Temperature Test" if it does not ignite

at the test temperature of 315°C (600°F)

.

.4 Test procedure.

(a) Apparatus . The tube furnace used for test, consists of a vertical cylinder [having ID x H dimensions of 12.5 x 12.5 cm (5 x 5 in)]

which is surrounded by electric heaters; i.e., sides, base, and top

(removable) . The cylinder is insulated and contained in a retaining

shell. (Note: One furnace type found suitable for test is that described

in ASTM Standard Method of Test for Autoignition Temperature of Liquid

Petroleum Products, ASTM D 2155-66.)

(b) Test flasks (which are supported within the refractory cylinder

of the tube furnace and which are used to receive samples injected into

the furnace) shall be commercial 200 cu cm Erlenmeyer borosilicate glass

containers

.

16
(c) Thermocouples

.

Three thermocouples (chromel alumel 28-gauge,

or equivalent) shall be used to measure flask temperature. Two of these

shall be mounted so as to contact the walls of the flask at 2. 5-5.0 cm

(1 and 2 in) locations from the neck of the flask and one shall be located

under the base of the flask at its center.

(d) Hypodermic syringe . A 0.25 or 1 cc capacity hypodermic

syringe equipped with a no. 18 stainless steel needle and calibrated

in units of 0.01 cu cm shall be used to inject fluid samples : nto the

test flask.

(e) Timer . An electric timer or stopwatch capable of at least

0.2-second interval measurements shall be used to determine times to

ignition for tests.

.5 Testing.

(a) Adjust the temperature of the furnace so that the temperatures

at the top, center, and bottom of the furnace flask are within + 1°C (2°F)

of the initial test temperature of 315°C (600°F).

(b) Ensure that the furnace flask is at equilibrium test temperature for at least 5 minutes before starting a test.

(c) Position a mirror at an appropriate location above the furnace

so that the inside of the furnace flask can be clearly observed.

17
(d) Fill the hypodermic syringe to a volume of 0.07 cu cm with

test fluid.

(e) Darken the testing room area so that ignitions may be more

easily observed.

(f) Place the hypodermic needle into the furnace top opening and

immediately discharge the test sample into the furnace flask and start

the timer.

(g) Observe the inside of the flask to determine if an ignition

occurs. The maximum time for observation is 5 minutes. (Note: Dry

air shall be used to flush the furnace flask after each test. Should

the flask become visibly coated with residue at any time it shall be

replaced with a new flask.)

(h) A new test shall be started, only after the furnace flask has

reached test temperature and remains at this equilibrium temperature for

at least 5 minutes before test.

.6 Test observations.

(a) If the 0.07 cu cm sample of test fluid does not ignite after 5 minutes of test at the test temperature of 315°C (600°F) , other fluid

volumes, e.g., 0.03, 0.05, 0.13, and 0.15 cu cm, shall also be subjected

to the same test at the same temperature.

18
(b) If none of these fluid volumes ignite at this test temperature,

the test fluid shall be considered to have met the requirements for

ignition resistance as promulgated by the Autogenous Ignition Temperature Test.

(c) If any of the fluid volumes do ignite at the test temperature

of 315°C (600°F) , the test fluid fails to meet the requirements of test.

(d) If the 0.07 cu cm sample of test fluid produces an ignition

at the test temperature of 315°C (600°F) , the candidate hydraulic fluid

fails to meet the requirements of the ignition test and no further

testing shall be required of the fluid.

.7 Report.

A report of test results shall include;

(a) Individual test results for each fluid volume tested, i.e.,

ignition or nonignition.

(b) For samples which ignited in the test, report the time at

which ignition occurred.

(c) A statement on whether a candidate hydraulic fluid meets

the requirements of the "Autogenous Ignition Temperature Test."

19
APPENDIX B

Temperature-Pressure Spray Ignition Test

for

Flammability Resistance of Hydraulic Fluids

.1 Scope and application.

The Code of Federal Regulations, Title 30, Part 35, lists three

different tests for measuring the flammability resistance of hydraulic

fluids

• Temperature-pressure spray ignition test.

• Autogenous ignition temperature test.

• Test to determine the effect of evaporation on flammability

of hydraulic fluids.

Candidate hydraulic fluids which meet all of the flammability

requirements of these tests are considered acceptable for use in

all underground coal mining operations.

Under Title 30, flammability resistant hydraulic fluids must

be used in the following mining operations;

(a) Where electrically powered equipment is used in attended

operations but where no fire suppression equipment is readily

available

20
(b) Where electrically powered equipment is used in unattended

operations

The following, provides procedures for test no. 1, "TemperaturePressure Spray Ignition Test," for measuring the flammability

resistance of hydraulic fluids.

.2 Definitions.

(a) Attended operations . Under Title 30, Chapter 1, Mining

Enforcement Safety Admin Sec 75.1107-1 (A-D) , attended operations

means — (1) any machine or device which is regularly operated by a miner and (2) any machine or device which is in direct line of sight

of a job site and within 500 feet of a miner working the job site.

(b) Unattended operations means all operations not covered by

the above definition for attended operations.

(c) Fire suppression equipment means any equipment capable of

discharging a fire extinguishing medium such as dry powder or other

type of material in sufficient quantity on a fire to bring it under

control and to extinguish it.

(d) Hydraulic fluid means any fluid which is used under

pressurized conditions to operate mining machines or devices.

21
(e) Fire resistant hydraulic fluid means any (d) fluid which

meets all requirements of the three tests cited in .1 Scope and

application.

.3 Summary of test.

Candidate hydraulic fluids are sprayed under specified

temperature and pressure conditions, i.e., 65 + 3®C (150 + 5®F)

and iiO ± i psi, into each of three different ignition sources!

(i) toroh flame, (2) electric sparks, and (3) flaming cotton.

?he ifnition eoureei are located at each of three different

ii§lan§i§ from the spray noisle, i.e,, 4S, 10, and 10 cm (II, 14,

ini li in) . eeterminations of flammability resistance are made,

bi§§i ©n i fluid’s ability to resist ignition as defined below.

(a) feat ©riteria . h candidate hydraulic fluid resists

ifniti©n and meets the flammability requirements of the spray test

if n©n§ ©I the ignitien scurees, at any test Iccaticn ignites the

hyif§uii§ fluid and ©auses a eentinueus flaming cenditien f©r i

§eg0ni§ ©¥ mere when fluid is sprayed aercss it.
.4 Test procedure.

(a) Apparatus (the spray ignition test apparatus is shown in

figure 1). (1) Test chamber or enclosure . Minimum dimensions for the

test chamber shall be 90 cm wide x 120 cm deep x 90 cm high (3x4x3 ft)

(see figure 2) . The chamber shall be equipped with an exhaust system

capable of removing fumes and smoke produced by testing.

(2) Spray nozzle . An atomizing round spray nozzle having a discharge orifice of 0.025 + 0.003 in diameter, capable of discharging

3.20 + 0.30 gallons of water per hour (GPH) with a spray angle of 90

degrees at a pressure of 100 + 5 psi shall be used for test (one suitable nozzle is Binks model F-12-25 or M-12-25) . The nozzle shall be

located or positioned at least 30 cm (12 in) from the base or floor

of the test enclosure. Note: If a cabinet is used as the enclosure,

the nozzle may be conveniently located or mounted on the sidewall of

the cabinet.

(3) Spray nozzle calibration . Each spray nozzle used for test

shall be calibrated for rate of fluid discharge. A preweighed plastic

bag of approximately 1 liter capacity shall be attached to the discharge end of the spray nozzle and water at nominal room temperature

of 18-26°C (65-80°F) shall be discharged from the nozzle into the

bag under 100 + 5 psi for 60 + 0.05 sec. The weight or volume of

water (specific gravity of water = 1 g per cu cm) shall be determined

by difference (weight of bag + water minus weight of bag) and this

V

23
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o

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24

FIGURE

1

SPRAY

IGNITION

TEST

APPARATUS
OJ

UJ

Qi3

CDH

Lj25

SPRAY

IGNITION

TEST

CHAMBER

(6)

Thermocouples . Two shielded thermocouples (chromel-alumel

or equivalent) shall be used for fluid temperature measurement. One

thermocouple shall be located in the test fluid in the cylinder or tank and the other in the tubing line just before the spray nozzle.

(7) Propellant medium . Test fluid shall be discharged through

the spray nozzle at 150 + 5 psi pressure by any means capable of

developing and maintaining that pressure. Two methods found suitable

for providing adequate discharge pressure are: (i) a circulating

pumping system and (ii) nitrogen, in commercially pressurized cylinders.

The spray test setup shall be equipped with the customary

regulators valves, tubing, and connectors and shall have the

capability of applying constant pressure over a wide range, e.g.,

100-1000 psi. Note: In the interest of safety all nonmetallic

tubing and hoses used in the setup shall have a safety factor rating

of at least 2 for temperature and 10 for pressure, i.e., above

operating test conditions.

(8) Timer . An electric timer or stopwatch capable of at least

0.2-second interval measurement shall be used to determine the duration of continuous flaming exhibited by a test fluid.

(9) Ignition devices . Three ignition devices shall be used to

provide three different ignition sources for test.

27
(i) Propane torch flame. This ignition source consists of a propane gas cylinder (one size found useful is a 14.1 oz by weight

or 1 pt. 10.7 fluid oz cylinder (bernzomatic or equivalent). The

cylinder shall be fitted with a burner head with an ID of 12.5 +

1.3 mm (0.5 + .05 in) and an orifice of 2.5 + .25 mm (0.1 + .01 in).

The torch flame used for test shall be 10-15 cm (4-6 in) in length.

(ii) Electric sparks . Electric sparks shall be provided for

test by a 12,000 volt transformer (Donegan type or equivalent) which

is allowed to discharge across a 0.5 in (12.5 mm) air gap or space

separating two horizontally mounted copper electrodes (straight

pencil type soldering iron tips) measuring 25 +2.5 mm (1.0 + .1 in)

in length and having a thickness of 3 + . 3 mm (0.12 + .01 in) . (See

figure 3 for illustration.)

(iii) Flaming cotton . The flaming cotton ignition source

consists of 50 + 1 gram of "cloth cotton cheesecloth (Type II, Class

2, 36 in) Fed. Supply No. 8305-00-205-3496" which is layered or folded

into a sample measuring 45 cm long x 5 cm wide (18 x 2 in); i.e.,

to fit inside a metal trough container (see figure 4) having similar

1 X w dimensions and measuring 5 cm ( 2 in) in depth. For test the

entire exposed gauze surface is wetted with 50 cu cm of kerosene

streaming from a 50 cu cm capacity glass pipette.

When ignited the ignition source shall provide an 45 cm (18 in)

long flame front with flame heights ranging from 10-15 cm (4-6 in)

.

28
ELECTRIC

SPARKING

DEVICE
LlI O3O

</) OHHH

CDH

bJ

a:33H

Ll.

OHHO

iDZHZ<3

Ll.I X33O

a:H3<

hliJ

30
Note: If after continuous testing the ignition source fails to

develop the desired flame height, inspect the ignition source and

determine whether additional kerosene is required or if the entire

cotton cheesecloth sample needs to be replaced.

(iv) Ancillary equipment includes, a pressure gauge (0-200 psi)

graduated in at least 5 psi steps, a linear scale, laboratory hot

plate, glass thermometer (0-100 °C)

,

glass pipette (50 cc capacity),

beakers (1 liter capacity), a wide mouth funnel, and bench stand

with clamps and kerosene.

(b) Testing . (1) Before beginning tests the spraying system

shall be checked for integrity and pressure leaks. A pressure gauge

(0-200 psi) shall be installed in the system in place of the spray

nozzle and the system shall be pressurized (without fluid) to 150 +

5 psi. All tubing, hoses, and valve connections shall be inspected

for leaks and all necessary adjustments shall be made to ensure that

the spraying system shall be capable of maintaining its pressurized

integrity throughout a testing series.

(2) The system shall then be depressurized and the pressure

gauge replaced in the system with the spray test nozzle.

(3) Test fluid shall be poured into the sample cylinder, tank,

or other type of vessel used for test. Note: The quantity of fluid

used for test may vary with the size or capacity of the vessel. If

the entry port to the vessel is small or narrow and the test hydraulic
fluid is viscous, it may be necessary to heat the test fluid to

an approximate test temperature of 65°C (150°F) before attempting

to add it to the vessel. Heating the fluid in beakers on a hot

plate to the approximate temperature should help reduce the time

required to fill the vessel.

(4) After filling, the fluid in the vessel shall be heated to

the test temperature of 65 + 3°C (150 + 5°F) and this temperature

shall be maintained for all tests.

(5) All necessary tubing and hose connections shall be made

and the system shall be pressurized to the test pressure of 150 +

5 psi

(6) Open the spray nozzle and discharge fluid through the system

for 5-15 seconds. Note: This is done to ensure that the tubing

leading from the vessel to the spray nozzle location is filled with

fluid which can then be heated (in the tubing) to the testing

temperature

(c) The propane torch flame test . (1) The propane fuel

cylinder used for test shall be supported on a bench stand (with the

aid of clamps) and the stand shall be positioned in the test chamber

with the burner tip of the cylinder set to produce a horizontal flame

that will be perpendicular to the path of a spray pattern.

32
(2) Tests shall be made with the burner tip located at three

different distances downstream from the spray nozzle; i.e., 18, 24,

and 36 in (45, 60, and 90 cm).

(3) Ignite and adjust the gas flame to produce a flame length

of 4-6 in (10-15 cm)

.

(4) With the burner tip positioned at the 18 in (45 cm) test

location, open the spray nozzle and start the timer.

(5) Cycle the torch flame into and out of the spray pattern at

a rate of approximately 15-20 cycles per min and observe whether the

fluid spray resists ignition (for 1 minute of spray time) or ignites

as evidenced by flaming for six continuous seconds or more. Note:

No spray test is run longer than 1 minute. In cases where an ignition

is observed the test shall be terminated immediately by stopping the

spray and timer.

(6) Record results for the torch test at the 18 in (45 cm) test

location

.

(7) Reposition the torch burner tip at the 24 in (60 cm) and

then the 36 in (90 cm) test locations downstream from the spray

nozzle tip and repeat the same spray test (as described above) at

each of these test locations.

33
(8) Record results for the torch tests at the 24 and 36 in (60

and 90 cm) test locations.

(9) Report results for all tests made at each test location in

the propane torch flame tests.

(d) Electric spark test . (1) The electric sparking device

shall be positioned in the test cabinet, perpendicular to the spray

pattern and with its electrodes the same distance from the floor of

the cabinet as the tip of the spray nozzle.

(2) Spark tests shall be made with the electrodes located at

distances of 18, 24, and 36 in (45, 60, and 90 cm) downstream from

the spray nozzle.

(3) Turn on the sparking device and ensure that it is working

properly

(4) Position the electrodes at the 18 in (45 cm) test location.

Open the spray nozzle and start the timer.

(5) Observe whether the fluid spray is ignited by the sparks

(i.e., flames continuously for 6 seconds or more) or resists ignition for 1 minute of spray. Note: No spray test shall be run longer

than 1 minute. In cases where an ignition is observed, the test

shall be terminated immediately, i.e., by stopping the sparking

device, spray, and timer.

34
(6) Record results for the electric spark test at the 18 in

(45 cm) test location.

(7) Reposition the sparking device with the electrodes located

at the 24 in (60 cm) and then the 36 in (90 cm) test locations downstream from the spray nozzle and repeat the same spray test (as

described above) at each of these test locations.

(8) Record the results for the electric spark tests at the 24 in

(60 cm) and 36 in (90 cm) test locations.

(9) Report results for all tests made at each test location in

the electric spark test.

(e) Flaming cotton test . (1) The metal trough containing the

prepared ignition source (kerosine soaked cotton cheesecloth) shall

be positioned in the test cabinet or enclosure, perpendicular to the

fluid spray pattern. In relation to the spray nozzle the top edge

of the trough shall be located 3.0 + 0.1 in (7.5 + 0.25 cm) below the

tip of the spray nozzle.

(2) Tests shall be made with the trough located at distances

of 18, 24, and 36 in (45, 60, and 90 cm) downstream from the nozzle.

(3) With the trough positioned at the 18 in (45 cm) test

location, ignite the cotton and ensure that 4-6 in (10-15 cm) high

flames are generated along the full length of the trough.

35
(4)

Open the spray nozzle and start the timer.

(5) Observe whether the fluid spray ignites (as evidenced by

continuous flaming for 6 seconds or more) or resists ignition for

1 minute of spray time. Note: No spray test shall be run longer

than 1 minute. In cases where an ignition is observed the test

shall be terminated immediately by stopping the spray and extinguishing the ignition source by closing the metal cover (attached to the

side of the trough) over the flames.

(6) Record the results for the flaming cotton test at the 45 cm

(18 in) test location.

(7) Reposition the trough at 60 and then 90 cm (24 and 36 in)

distances downstream from the spray nozzle and repeat the spray test

(as described above) at each test location.

(8) Record results for the flaming cotton tests at the 60 and

90 cm test locations.

(9) Report results for all tests made at each test location in

the flaming cotton test.

(f) Acceptance . (1) Candidate hydraulic fluids meet the

requirements of .3(a) Test criteria if they produce nonignition

36
results for all three ignition sources (i.e., propane torch flame,

electric sparks, and flaming cotton) at all test locations.

(2) Report whether the candidate hydraulic fluid meets the

requirements of the Temperature—Pressure Spray Ignition Test.

37
APPENDIX C

Test for the Effect of Evaporation on the Flammability

of Hydraulic Fluids

.1 Scope and application.

The Code of Federal Regulations, Title 30, Part 35, lists three

different tests for measuring the flammability resistance of

hydraulic fluids.

o Temperature—pressure spray ignition test;

o Autogenous ignition temperature test;

o Test to determine the effect of evaporation on flammability

of hydraulic fluids.

Candidate hydraulic fluids which meet all of the flammability

requirements of these tests are considered acceptable for use in all

underground coal mining operations.

Under Title 30, flammability resistant hydraulic fluids must be

used in the following mining operations;

(a) Where electrically powered equipment is used in attended

operations but where no fire suppression equipment is readily

available.

38
(b) Where electrically powered equipment is used in unattended

operations

The following, provides procedures for test no. 3, "Test for

the Effect of Evaporation on the Flammability of Hydraulic Fluids."

.2 Definitions.

(a) Attended operations . Under Title 30, Chapter 1, Mining

Enforcement Safety Admin Sec 75.1107-1 (A-D) , attended operations

means-- (1) any machine or device which is regularly operated by

a miner and (2) any machine or device which is in direct line of

sight of a job site and within 500 feet of a miner working the job

site

(b) Unattended operations means all operations not covered by

the above definition for attended operations.

(c) Fire suppression equipment means any equipment capable of

discharging a fire extinguishing medium such as dry powder or other

type of material in sufficient quantity on a fire to bring it under

control and to extinguish it.

(d) Hydraulic fluid means any fluid which is used under

pressurized conditions to operate mining machines or devices.

39
(e) Fire resistant hydraulic fluid means any (d) fluid which

meets all requirements of the three tests cited in . 1 Scope and

application.

.3 Summary of test.

(a) The test uses a cycling device, a bunsen burner (methane

gas) flame ignition source and fluid soaked wicks for measurement

of the effect of evaporation on the flammability resistance of

hydraulic fluids.

In the test, samples are cycled (at a prescribed rate) into the

burner flame until a sustaining flame is observed on the wick. The

number of cycles required to ignition are counted and fluids which

resist ignition for the number of cycles prescribed in .3(b) Test

criteria, meet the flammability requirements of the test.

(b) Test criteria . A candidate hydraulic fluid meets the

flammability requirements of the "Wick Test," if the material meets

or exceeds the minimum (5 set) test average for each test condition.

(See table 4 .

)

40
Table 4. Wick Test Criteria

Sample - Minimum No. of Cycles (5 Test Ave.)

As received fluid 24

2-Hour oven conditioned 18

fluid*

4-Hour oven conditioned 12

fluid*

* Oven evaporation temperature 65 + 1°C (150 + 2°F)

.

.3 Test procedure.

(a) Apparatus . (1) The cycling device used for Wick Test

shall have the capability of cycling samples in a horizontal plane

(through a 90 degree arc) into a bunsen flame ignition source at

the rate of 25 + 2 cycles per minute. Note: An automobile windshield wiper mechanism or other device capable of producing the

specified cycling rate may be used for test.

(2) Ignition source . A bunsen burner with an orifice of 1.25-

1.60 mm (0.06-0.08 in) and with ID x H dimensions of 1.3 x 16.5 cm

(0.5 X 6.5 in) fired with methane gas (96.1 + 1 percent methane)

shall be used as the ignition source for test.

(3) Flowmeter . Gas flow to the bunsen burner shall be monitored

by a flowmeter calibrated for methane gas delivery over a range of

1133-1882 cc per min (0.04-0.07 cu ft per min) at STP.
(4)

Oven. A non-air-circulating gravity convection oven

operated and maintained at a temperature of 65 + 1°C (150 + 2°F)

shall be used for test.

(5) Wicks . Pipe cleaner stems (one type found suitable--Dill

U.S. Tobacco Company) having a base wire thickness of 0.75-1.0 mm

(0.03-0.04 in) and a combustible content of 0.006-0.01 g per cm of stem

length shall be used for test. Note: The combustible content is

determined by weighing a full length pipe cleaner (=15 cm) before

and after burning away the tufting material on the cleaner. The

weight difference divided by stem length equals weight loss per cm

of stem.

(6) Petri dishes . Standard laboratory heat resistant glass

petri dishes 13 mm (0.5 in) deep and 88 mm (3.5 in) in diameter

fitted with matching lid covers shall be used to contain fluid

samples for oven evaporation and testing. Note: The lids shall

be used to cover the dishes immediately after their removal from

the oven

(7) Ancillary equipment . An electric timer or stopwatch

capable of at least 0.2 sec interval measurement shall be used for

timing the cycling device. Tweezers shall be used for handling

all wick samples.

(b) Sample preparation . (1) Prepare a total of 15 v/icks,

each 7.5 cm (3 in) long, for tests on each candidate hydraulic fluid.

42
(2) Pour 30 cc of test fluid into each of three different

petri dishes. Set one dish aside for tests on the fluid in its

as received condition and place the other two dishes (uncovered)

into the oven [operated and maintained at 65 + 1°C (150 + 2°F) ] .

(3) After 2 hours, remove one of the dishes from the oven and

cover it immediately with its matching lid and set the dish aside

to cool to room temperature 17-26°C (65-80°F)

.

(4) After 4 hours, remove the remaining dish from the oven and

repeat the above procedures for covering and cooling the fluid sample.

(5) A total of five wicks shall be allotted for tests on each

of the fluid samples, i.e., as received and 2 and 4 hours.

(6) Use tweezers to place the wicks into each of the dishes

containing the test fluids and allow each wick to soak in the fluid

sample for at least 2 minutes. Note: To ensure complete wetting,

use tweezers to move the wicks around in the test fluid.

(7) After soaking for 2 minutes or more, each test wick shall

be removed from the dish and shall be supported in a holder to drain

for at least 2 minutes but no longer than 5 minutes, before testing.

43
(c) Testing preparations . (1) All testing shall be conducted

in a draft-free location equipped with facilities for exhausting

smoke and fumes produced by testing.

(2) With a spare wick mounted in the wick holder ensure that

the vertical distance from the wick to the burner top is 7.5 + 0.3 cm

(3.0+ 0.125 in)

.

(3) Turn on and monitor the cycling device to ensure that the

wick cycling rate is 25 + 2 cycles per minute and that the midpoint

of a cycle ends with the wick directly over the middle of the burner

top

.

(4) Turn on and adjust the methane gas flow to the burner to

0.05 cu ft per min (1444 cc per min). Note: The burner flame shall

be blue, have no appreciable inner cone, and be 10-15 cm (4-6 in)

in height.

(5) At the start of a test the wick holder arm shall be located

at one extreme end of a cycle, i.e., farthest away from the burner

flame. Mount a fluid soaked wick sample into the holder (use

tweezers) and ensure that a 5+ 0.2 cm (2+0.1 in) length of stem

extends horizontally from the holder end.

(d) Testing . (1) Start the cycling device and record the

number of times that the test wick cycles into the burner flame

until a self-sustaining flame is observed on the wick. Note: A

44
self-sustaining flame is defined here as one in which the wick

becomes ignited and travels while flaming to the extreme end of a

cycle (away from the burner) and is still flaming on its return and

reentry into the burner flame.

(2) A total of five replicate tests shall be made on each of

the three samples (as received and 2 and 4 hours) of each fluid.

(3) Average values for each (5 test) set on each of the above

test samples shall be taken as test results.

(e) Acceptance . To be classified as meeting the flammability

requirements of the wick test, candidate hydraulic fluids must meet

or exceed the minimum number of cycles cited for the different

samples of fluid as outlined in .3(b) Test criteria.

'p'' Report . A report of test results shall include:

(1) Individual test values (no. of cycles to ignition for each

test) .

(2) The average value for five replicate tests on each different

sample of a test fluid.

(3) A statement on whether a candidate hydraulic fluid meets

the requirements of the "Test for the Effect of Evaporation on the

Flammability of Hydraulic Fluids."

45
NBS-llitA igEv, 2 -ec) U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication'Date I BIBLIOGRAPHIC DATA

REPORT NO.

SHEET (See instructions) NBSIR81-2395 October 1981

4. TITLE AND SUBTITLE

AN ASSESSMENT OF THREE DIFFERENT FIRE RESISTANCE TESTS FOR HYDRAULIC FLUIDS

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.

8. Type of Report & Period Covered

Final Report

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

U.S. Bureau of Mines

Pittsburgh, Pennsylvania 15213 and Mine Safety and Health Administration

Triadelphia, West Virginia 26059

10. SUPPLEMENTARY NOTES

I I Document describes a computer program; SF-185, FIPS Software Summary, is attached.

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

bibliography or literature survey, mention it here)

The Center for Fire Research (CFR) at the National Bureau of Standards (NBS) at the

request of the Mine Safety and Health Administration (MSHA) and the Bureau of Mines

(BOM) made an evaluation or assessment of the three different flammability tests

used by MSHA for measuring the fire resistance of hydraulic fluids intended for use

in underground coal mining operations. The methods described in the Code^of Federal

Regulations Schedule 30, Part 35, consist of the following: an Autogenous Ignition

Temperature Test, a Temperature—Pressure Spray Ignition Test, and a Test to

Determine the Effect of Evaporation on the Flammability of Hydraulic Fluids.

This report summarizes the various studies conducted in the evaluation and provides

recommendations for improvement of the three test procedures.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) Autoignition temperature; coal mines; fire point; fire resistance tests; fire

tests; flammability; flash point; hydraulic fluids; ignition.

13. AVAILABILITY

Uni i mi ted

I I For Official Distribution. Do Not Release to NTIS

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

20402.

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

14. NO. OF

PRINTED PAGES

49

15. Price

$6.50

USCOMM-DC 6043-P80

iI i 1