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Paper 0701

Biobased Lubricants for Tunnel Boring Machines

Hocine Faci Bob Cisler

BP/Castrol

150 W. Warrenville Rd Naperville, IL 60563

Presented at the 74th NLGI annual meeting Scottsdale, Arizona

June 9 -12, 2007

NLGI Preprint: Subject to revision. Permission to publish this paper, in full or in part, after its presentation and with credit to the author and theInstitute, may be obtained upon request. NLGI assumes no responsibility for the statements and opinions advanced by contributions to its publications. Views expressed are those of the authors and do not necessarily represent the official position of the NLGI.

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Biobased Lubricants for Tunnel Boring Machines Abstract Special seal compounds have been developed over the last two decades based on the requirements of major Tunnel Boring Machine (TBM) manufacturers to help protect major rotating elements such as the TBM main bearing (front end of TBM) from water, mud and dust and to seal off the tail end of the TBM from the ingress of water. The main features of seal compounds are good water resistance and tackiness for maximum sealing capabilities as well as good pumpability and ease of product distribution. In addition, environmental friendliness along with fire resistance properties are highly desired. Front seal compounds provide also a lubrication function for the extra protection of the elastomer lip seals used for the rotary elements of most TBMs. Two products, based on biodegradable base oils, were developed for this purpose. Tested against conventional polymeric compounds in a major city subway tunneling system as well as in urban sewage networks, these products showed excellent sealing capabilities and outstanding lubrication performance leading to a tangible reduction in product consumption. Introduction Figure 1: Tunnel Boring machine (diameter 7.34 m) [3]

Wikipedia.com [1] defines the tunnel boring machines (TBM) as equipment used to excavate tunnels with a circular cross section through a variety of geologies. The rock to be removed is disintegrated by continuous rotation of a group of cutting tools thrust against the surface of the rock at the working face. Unlike the Drill and Blast (D&B) tunnel, the TBM tunnel has the advantage of not disturbing surrounding rock when cut and producing a smooth tunnel wall. They can be used to bore through hard rock or sand and almost anything in between. This significantly reduces the cost of lining the tunnel, and makes them suitable to use in built-up areas. The key disadvantage is cost. TBMs are expensive to construct, difficult to transport and require significant infrastructure. Tunnel diameters can range from one meter to 15 meters. The cutterhead rotates at low rotation speed (4-10 rpm) and the cutters mounted on the face of the TBM cut the rock into chips. The excavated rock chips are dropped into a conveyor belt system that discharges the dirt into the final transportation system out of the tunnel [2]. Figures 1 and 2 show two models of these machines currently in use for tunneling [3, 4].

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Figure 2: World’s largest tunnel boring machine

(Inner cutting wheel: 7.0 m, Outer cutting wheel:

15.2 m) [4] Figure 3 [5] illustrates the main parts of a TBM. Special seal compounds have been developed over the past 2 decades based on the requirements of major Tunnel Boring Machines (TBM) manufacturers to help protect major rotating elements such as the TBM main bearing (front end of TBM) from water, mud and dust and to seal off the tail end of the TBM from the ingress of water. The use of seal compound became especially important for TBMs operating in soft/mixed ground conditions (vs. hard rock) and where advanced tunnel lining techniques are used. Thus not all TBMs need seal compounds and not all the TBMs operating in soft mixed/ground are designed to use front seal compounds [6].

Figure 3: TBM Main Parts [5] The main features of seal compounds are good water resistance and tackiness for maximum sealing capabilities as well as good pumpability and ease of product distribution. In addition, environmental friendliness, including product biodegradability, is desirable. Front seal compounds also provide a lubrication function for the extra protection of the elastomer lip seals used for the rotary elements of most TBMs. Seal compounds are pumped into the sealing areas through the use of automatic systems and are total loss applications. Front seal compounds are virtually continuously pumped into the sealing areas. Special brushes are used for the tail sealing which are filled with the tail seal compound. The product application rate is based on operating requirements and is generally determined by the TBM operator. In some applications, conventional grease sealing systems are used. There are also attempts to find other approaches, especially for front end sealing, to minimize the high costs associated with the use of special seal compounds

This paper will discuss the performance displayed by non-conventional products in comparison with polymer based products that traditionally have provided adequate

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sealing. The physical properties as well as the performance characteristics of these products will be covered along with the product consumption and its impact on the tunneling process.

Background

The front seal compound (FSC) is used on the front cutter head side of the TBM. The rotating cutterhead is supported by a large diameter roller thrust bearing, which is one of the most critical TBM components. Failure of this costly bearing system will shut down the TBM. Replacement costs are extremely high. Elaborate sealing systems, such as elastomer lip seals, are in place to protect this main bearing which is generally oil lubricated with an oil circulation system. The FSC is pumped continuously into the sealing system in the front of the lip seal system. This is a total loss application. The FSC will end up in the excavated dirt, transported on conveyor belts out to the truck waiting outside the tunnel.

Prior to the development of special seal compounds, Extreme Pressure (EP) grease had been used as the seal material and is still being used on some TBMs. One reason for the occasional use of a grease is the lower cost vs. seal compounds which are generally 2-3 times more expensive.

The tail seal compound (TSC) is for use at the tail end of the TBM. Special rings of so called wire brushes and steel plates are installed on the circumference of the TBM shield. These brushes, together with the TSC, which is pumped into the wire brushes, provide a seal which resists the infiltration of water. The TSC also acts as a lubricant for the wires to increase their operation life.

While the traditional high viscosity polymeric type products fortified with solid fillers/ fibers can provide acceptable sealing capabilities along with water resistance, field experience has shown that the lubricant’s performance wouldn’t categorically improve with an increase in viscosity. The mobility of the seal compound, which results from having a low viscosity, determines to some extent the product performance; good pumpability, dispensability, distribution, and spreadability in the application area. On the other hand, low viscosity oil based compounds have a tendency to lack adhesion and water resistance, resulting in inadequate sealing properties. In conclusion, the ideal products for these applications would be products that display the following characteristics:

• Ability to pump through a lubrication system at the tunnel temperature, spread in a film that is resistant to infiltration of higher pressure water

• Sufficient tackiness/adhesion to make the product adhere strongly to the dry and wet surfaces for proper sealing

• Friction and wear reduction for extended service life of the protected components

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• Biodegradability to meet increasingly more stringent environmental protection requirements especially for a total loss product that ends up in the excavated dirt such as in a tunneling operation, and finally

• Fire resistance (or fire retardant) properties to inhibit fire ignition and/or limit its propagation.

Laboratory evaluation

Two samples of conventional commercially available front and tail seal compounds (CA-FSC and CA-TSC) were evaluated in order to determine their performance properties under laboratory test conditions. Standard test methods were used for evaluation of water resistance, pumpability, wear and extreme pressure characteristics, oil retaining properties, thermal retention, evaporation loss, and compatibility with sealing material. An in-house developed test for fire resistance property was conducted on both samples. The following summarizes the laboratory test methods deemed to be appropriate for evaluating and comparing seal compounds:

Water resistance

In grease lubrication applications water contamination may cause the structure of the grease to change. It may become softer or harder. It may adsorb water or reject it, and in some instances, it may lose its adhesion or sealing capabilities.

Water Spray-off (ASTM D 4049)

This method consists of subjecting an evenly distributed layer of lubricant spread at a given thickness on a stainless steel panel to water spray-off. The lubricant is sprayed with tap water at a given temperature for 5 minutes at a prescribed pressure. The panel is then air dried and weighed. Spray-off resistance is reported as the mass percent of lubricant removed by the water spray. Two temperatures, 38°C and 50°C, were deemed appropriate for covering the tunnel temperatures surrounding the application.

Extreme Pressure / Anti wear

Equipment such as the Four Ball EP and Four Ball Wear tester, to name only two, have played and continue to play a critical role in the development, testing and selection of lubricants.

Four Ball EP (ASTM D 2596)

This method consists of 4 balls arranged in the form of an equilateral tetrahedron. The basic elements of the tetrahedron are 3 balls held stationary in a pot to form a cradle in which the fourth (upper) ball is rotated on a vertical axis under pre-

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determined conditions of loads. The rotating speed is 1770 +/- 60 rpm. A series of 10-second runs are made at successively higher loads until the 4th ball seizes/welds to the 3 stationary balls.

Four Ball Wear (ASTM D 2266)

This method uses the same principle as above. The test is run at a specified rotational speed under a prescribed load at a controlled temperature. The test standard duration is 1 hour. The diameter of the wear scars on the stationary balls is measured after completion of the test.

Friction

Multiple test apparatus and numerous methods are employed to measure friction at the contacting surfaces of various shapes and sizes of test specimens. Apparatus includes Four Ball, Pin and Vee, Ring on Block, Block on Ring, Disk on Disk, and Ball on Disk Testers. The SRV test machine was selected for measuring the coefficient of friction in this project.

Friction (ASTM D 5707 modified).

Test specimens consisting of a steel ball oscillating on a steel disk. A detailed description of the SRV test machine can be found in references [7] and [8].

Pumpability, Lincoln Ventmeter

The assembly consists of a 25 ft long coil of inch copper tubing with a gauge at one end and a grease fitting at the other end. The grease is pumped into the ventmeter until the pressure has developed to 1800 psi. When the testing temperature is reached, the pressure is then vented. The pressure on the gage at the end of 30 seconds is the Ventmeter pumpability at the testing temperature [9].

Oil Retaining Properties (JIS A 5751 /Japanese Industrial Standards)

A small amount of grease (2.0 gr) is placed on a pile of 9 sheets of filter paper. The pile with grease is placed in an oven at 50°C for 24 hours. Upon test completion, the sample is removed from the oven and the distance (in mm) the oil has traveled is reported as well as the number of filter papers it has penetrated. Flowing Off Test (JIS A 5758) It consists of filling with seal compound a channel jig made of corrosion resistant metal plate; placing the assembly in a thermostatic oven in a vertical position at a given temperature for 6 hours. The slump value will be expressed by the distance (in mm) between the lower end of the channel of the jig and the undermost dropping end of the specimen. If a total slump of the grease occurs before the 6 hour duration elapses, the time at which the total slump occurred will be reported instead.

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Base Oil Flash Point, Fire Point (ASTM D 92)

It consists of filling a test cup with the base oil, increasing the temperature rapidly at first and then at slower constant rate as the flash point is approached. At a specified interval of time, a flame is approached to the cup surface. The flash point is the lowest temperature at which the sample ignites. To determine the fire point, the test is continued until the application of the test flame causes the specimen to ignite and sustain burning for at least 5 seconds.

Compatibility with Seal Materials (ASTM D 4289)

This test consists of determining the volume change of a coupon of elastomer immersed in test grease for 70 hrs at 100°C. The volume change in percentage is measured by the volume of water displaced.

Fire Resistance

It consists of filling a flat metal recipient (can lid for example) with the seal compound, then applying a flame to the sample surface until the product ignites. The burning time, the way the flame propagates, and the appearance of the surface after the flame dies are reported.

Biodegradability

Measuring the biodegradable property of lubricants remains a work in progress at both national and international standards level. ASTM D-5864, EPA Shake Flask, CEC-L-33-A-93, ISO 9439, OECD 301 A to F, and OECD 302 are a few of tests currently used to measure the biodegradability of lubricants.

Biodegradability Test (OECD 301B)

The OECD 301B test method has been found to be suitable for determining the ready biodegradability of soluble and insoluble organic chemicals under aerobic conditions. It is the basis for ISO 9439. This method is only applicable to those test materials which, at the concentration used in the test, have negligible vapor pressure, are not inhibitory to bacteria and do not significantly adsorb to glass surfaces. In general, bio-based greases fit this category of substances.

Percentage biodegradation is calculated by dividing the Biological Oxygen Demand (BOD) by the Theoretical Oxygen Demand (ThOD). The calculation of ThOD is based on the percentage composition of the elements C, H, Na, Cl, P, and S. A sample with high water content and/or low carbon content will have a correspondingly high oxygen value (this being calculated by difference). This will result in a low estimation of the ThOD, and as a consequence, an overestimation of the percentage biodegradability. The elemental analysis for aqueous samples may also be harder to achieve. Due to these difficulties, Chemical Oxygen Demand (COD) values can be used as an alternative to ThOD.

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Laboratory Test Results:

Evaluation of Commercially Available Seal Compounds

Table 1 summarizes the results obtained on commercially available products.

Although the specification requirements are not well defined by the OEMs for either compound, there is however a tendency to lean towards the usage of high viscosity oil based compound that provides improved tackiness/adhesion as determined by Flowing Off testing and Water Sprayoff resistance in the presence of synthetic sea water. Lubrication performance is determined by Four Ball EP and Wear especially for Tail Seal Compound. The other requirements were set based on average data obtained on current or previous commercially available seal compounds. Based on these specifications, it was proven that both CA-FSC and CA-TSC met and in many situations exceeded the specification requirements, namely visual appearance, tackiness/adhesion, water resistance, oil retention, mobility and lubricity properties. Consistency or NLGI grade as determined by worked penetration was slightly off the grade on the stiff side. This type of product, given the nature and the high amount of solids present, has a tendency to heavy up over time under storage conditions. No information was made available on base oil flash point, fire point or even viscosity. The grease extracted oil was deemed not representative of the actual base oils for determining these characteristics because of the polymeric nature of the base oils used in these seal compounds.

Development of Seal Compounds

The objective was to develop compounds that meet all the specification requirements as shown in Table 1 and that perform similarly or better than the current commercially available products in the areas that were not covered by the specified requirements. Also, the new developed products must be biodegradable and have an improved fire resistance capacity. Tables 2 and 3 list the test results obtained on new developed front seal compound and tail seal compound respectively.

Tackiness / adhesion

The new developed FSC and TSC are based on a high viscosity vegetable oil compound that is characterized by high tackiness/adhesion towards metal surfaces given its polar nature. The Flowing Off test shows that these two products tend not to flow off at ambient temperature (25°C) for the whole duration of the test (6 hrs). They did flow off after > 3 hrs at 35°C and after > 1 hour at 50°C, while the CA-FSC and CA-TSC slump down after only 1 hour at 35°C and after only 20 minutes at 50°C. This was regarded by the OEM as a remarkable result if the other performances remained acceptable.

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Water resistance

One of these OEM primordial requirements is water resistance in the presence of synthetic sea water since a good performance with sea water would imply automatically a good result with ordinary underground water. Results shown in Table 2 and 3 indicate that the new developed biodegradable B-FSC and B-TSC have outstanding water resistance not only at standard testing temperature (38°C) but also at higher temperatures. Weight losses remain below 7.0% even at 50°C when tested against tap water for B-FSC while the results obtained on CA-FSC and CA-TSC were marginal.

Pumpability by Lincoln Ventmeter

While the new developed B-FSC was similar to the CA-FSC in Lincoln Ventmeter testing, the new developed B-TSC showed better results than the CA-TSC. This margin of security would be extremely helpful in applications where water is abundant in the tunnel surroundings; it allows the usage of a heavier compound for advanced sealing with still acceptable pumpability.

Water resistance and Pumpability relationship

As stated above, water resistance and pumpability are characteristics that move in opposite directions. Better water resistance (lower sprayoff figures) implies poorer pumpability (higher Lincoln Ventmeter numbers) and since water resistance is intimately impacted by the grease consistency (worked penetration), a correlation between pumpability and water sprayoff has been established for the case of FSC (see figure 4). This graph indicates that the B-FSC could be brought to an outstanding pumpability (below 400 Psi) with still acceptable result (around 7% loss) for water sprayoff.

Figure 4: Water Resistance / Pumpability relationship

Water Resistance/Pumpability Relationship

B-FSC vs. CA-FSC

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6 7 8 9 10

Water Sprayoff, % w Loss

Ventmeter

result, Psi

B-FSC

CA-FSC

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Lubricity Characteristics

The extreme pressure characteristics as determined by Four Ball EP, Four Ball Wear and SRV test machines show the superiority of the bio-based products in comparison with the conventional polymer based products. Table 2 and 3 and Figure 5 illustrate these results.

Figure 5: Friction by SRV tester

0

0.2

0.4

0.6

0.8

0 20 40 60 80 100 120 140 160

Time, sec

Friction

Friction, CA-FSC(Red) & B-FSC(Black), 50/100/200N, 1mm, 50Hz

Testnr

5655

Flash Point, Fire Point and Fire Resistance

Although there were no data on flash point or fire point of the benchmarked seal compounds, it was accepted based on knowledge of polymeric base oils that they meet the specification requirements as shown in Table 1. The newly developed bio-based compounds displayed in contrast significantly higher flash and fire points in comparison with the spec. requirements. This would explain in part as to why the fire resistance capacity of the bio-based products was significantly better than the fire resistance of the conventional seal compounds.

Figure 6 shows that the B-TSC and B-FSC sustained the flame only for 4 and 6 minutes respectively while the CA-TSC and CA-FSC sustained the flame for 15 and 16 minutes respectively. The visual inspection of the burned samples show localized burning of the bio-based products. The usage of high viscosity vegetable oil resists burning and propagation of fire. This is due to the formation of an isolating layer of polymerized vegetable oil, which prevents contact between the atmospheric air and the burning product. As far as the conventional polymer based products, the flame has smoothly propagated to the whole surface of sample and continued to be sustained until all the combustible compounds have been completely burned off.

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Biodegradability

Both new developed products showed a readily biodegradability (over 60% ThOD) as per the OECD 301B test method. No biodegradation test has been run on the CA-FSC or on CA-TSC. These compounds should exhibit poor results in these tests because of the nature of the base oils used to make these products.

Field Testing

Two case studies can be discussed to evaluate the performances of the B-FSC and B-TSC.

A metro transport tunneling project: The tunneling section of a major metropolitan public transport system consisted of two 1400 ft long and 21 ft diameter tunnels. A refurbished Earth Pressure Balance Machine was used. Tunnel lining was precast concrete segments. Four segments form a complete liner ring. The conclusions of this case study report the following:

- Excellent sealing of the cuttinghead main bearing and tail seal system,

- Very good pumpability and flowability of the seal compounds in the sealing system

- Average seal compound consumption rates under present operating conditions as measured per liner ring (4 ft)

- Contractor very satisfied with the performance of both products

The second case study relates to sewer overflow tunneling program at a major metropolitan municipality public works. This machine required FSC only. This project consisted of the construction of 8200 ft long and 12 ft finished diameter underground tunnel. A refurbished TBM was used for tunneling under mixed/soft underground conditions. B-FSC was used to provide extra protection of the cuttinghead main bearing. The case study conclusions were as follows:

- Excellent sealing of the cuttinghead main bearing

- Spectrographic and infra-red analysis of a gear oil grade oil used for lubrication of the main bearing, showed no presence of the B-FSC in the oil, indicating good sealing capabilities of the B-FSC

- Very good pumpability of the B-FSC through a hydraulic operated keg pump

- Good to excellent seal compound consumption rates.

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Conclusions

Based on both the laboratory testing and field evaluation data of the bio based seal compounds, it is believed that their superior tackiness/adhesion characteristics, their high resistance to water sprayoff, their outstanding pumpability and good extreme pressure and anti wear properties in slow and heavily loaded applications, makes these bio-based products excellent seal compounds for tunneling systems. The biodegradability as well as the fire resistance characteristics contribute not only to the safety and the security of operation but also to the protection of the environment.

Acknowledgements

The authors wish to express their gratitude to E. Hubner, Steve Reardan, Chuck Barrett and John Haspert for the support they provided during the development and field testing of these compounds

References

[1] Tunnel Boring Machines, http://www.Wikipedia.org [2] E. Hubner, “The Tunneling Market & Seal Compounds for Tunnel Boring Machines”, Castrol Industrial North America, March 1998 (Internal Publication) [3] Tunnel Boring Machine, http://www.sara-tx.org [4] World’s Largest Tunnel Boring Machine Accepted by the Customers, http://www.herrenknecht.com [5] The machine tunneling under London, http://news.bbc.co.uk/1/hi/uk/2225861.stm [6] E. Hubner, Seal Compounds-Product Launch”, Castrol Industrial North America, March 2000 (Internal Publication) [7] H. Faci, I. Bjel, A. Medrano, B. Cisler “Frictionless Open Gear Lubricant” , NLGI

Spokesman, Vol. 66, Nr 6, September 2002 [8] H. Faci, A. Medrano, B. Cisler “Biodegradable Open Gear Lubricant”, NLGI

Spokesman, Vol. 67, Nr 12, March 2004 [9] The Lubrication Engineers Manual, AISE, 1996.

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Table 1: Laboratory Test Results / Commercially Available Seal Compounds

Characteristic Test Method CA-FSC(*) FSC Spec CA-TSC(**) TSC Spec

Thickener type -- NA(***) NS(****) NA NS

NLGI Grade -- 2 2 2 2

Worked Penetration, 1/10 mm @ 25°C D 217 259 265-295 260 265-295

Appearance Visual Fibrous Fibrous Fibrous Fibrous

Color Visual Dark grey NS Light amber NS

Tackiness/adhesion Visual Tacky /

adhesive

Tacky / adhesive Tacky / adhesive Tacky / adhesive

Base oil viscosity, cSt @ 40°C D 445 NA NS NA NS

Water Sprayoff, % loss

Synthetic sea water, 38°C

Tap water, 38°C

Tap water, 50°C

D 4049

7.59

6.69

9.78

7. 0 max

--

--

3.66

--

--

7. 0 max

--

--

Pumpability, Lincoln Ventmeter

Psi @ 25°C

-- 800 NS 600 NS

Base oil , Flash Point,°C

Fire Point, °C

ASTM D 92 NA

NA

120 min.

205 min.

NA

NA

120 min.

205 min.

Oil Retaining Properties

mm / # paper filters

JIS A 5751

12/2

12 max/5 max

12/2

12 max/5 max

Flowing Off Test, minutes @ 25°C JIS A 5758 > 360 > 30 > 360 > 30

Four Ball EP, kg weld D 2596 400 NS 620 315 min.

Four Ball Wear, mm D 2266 0.89 0.90 max 0.89 0.90 max

SRV Test, Steel ball/Steel Disk

50-200 N, 50°C, 50 Hz, 1.0 mm

Coefficient of Friction

Wear (microns change)

D 5707

(modified)

0.54

9.3

NS

NA

NS

Specific Gravity D 1475 1.190 1.15-1.25 1.162 1.15-1.25

Compatibility with seal material,

% volume change

D 4289 NA NS - 3.70 NS

Biodegradability, % OECD 301B NA NS NA NS

(*) CA-FSC: Commercially Available Front Seal Compound

(**) CA-TSC: Commercially Available Tail Seal Compound

(***) NA: Not available, (****) NS: Not Specified

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Table 2: Laboratory test results / Biodegradable Front Seal Compound

Characteristic Test Method B-FSC(*) CA-FSC(**) Specifications

Thickener type -- Proprietary NA(***) NS(****)

NLGI Grade -- 2 2 2

Worked Penetration, 1/10 mm @ 25°C D 217 264 259 265-295

Appearance Visual Fibrous Fibrous Fibrous

Color Visual Dark grey Dark grey NS

Tackiness/adhesion Visual Extremely

tacky/adhesive

Tacky / adhesive Tacky / adhesive

Base oil viscosity, cSt @ 40°C D 445 2440 NA NS

Water Sprayoff, % loss

Synthetic sea water, 38°C

Tap water, 38°C

Tap water, 50°C

D 4049

1.22

0.95

1.20

7.59

6.69

9.78

7. 0 max

--

--

Pumpability, Lincoln Ventmeter

Psi @ 25°C

-- 775 800 NS

Base oil , Flash Point, °C

Fire Point, °C

ASTM D 92 227

293

NA

NA

120 min.

205 min.

Oil Retaining Properties

mm / # paper filters

JIS A 5751

6/3

12/2

12 max/5 max

Flowing Off Test, minutes

@ 25°C

@ 35°C

@ 50°C

JIS A 5758

> 360

> 180

> 60

> 360

> 60

< 20

> 30

--

--

Four Ball EP, kg weld D 2596 400 400 NS

Four Ball Wear, mm D 2266 0.67 0.89 0.90 max

SRV Test, Steel ball on Steel Disk

50-200 N, 50 °C, 50 Hz, 1.0 mm

Coefficient of Friction

Wear (microns change)

D 5707

(modified)

0.19

7.5

0.54

9.3

Specific Gravity D 1475 1.209 1.190 1.15-1.25

Biodegradability, % OECD 301B 75 NA NS

(*) B-FSC: Biodegradable Front Seal Compound

(**) CA-FSC: Commercially Available Front Seal Compound

(***) NA: Not available, (****) NS: Not Specified

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Table 3: Laboratory test results / Biodegradable Tail Seal Compound

Characteristic Test Method B-TSC(*) CA-TSC(**) Specifications

Thickener type -- Proprietary NA(***) NS(****)

NLGI Grade -- 2 2 2

Worked Penetration, 1/10 mm @ 25°C D 217 285 259 265-295

Appearance -- Fibrous Fibrous Fibrous

Color -- Light grey Light amber NS

Tackiness/adhesion -- Extremely

tacky/adhesive

Tacky / adhesive Tacky / adhesive

Base oil viscosity, cSt @ 40°C D 445 3300 NA 2500 min.

Water Sprayoff, % loss

Synthetic sea water, 38°C

D 4049 0.81 3.66 7.0 max

Pumpability, Lincoln Ventmeter Psi @

25°C

-- 250 600 NS

Base oil , Flash Point, °C

Fire Point, °C

ASTM D 92 207

282

NA

NA

120 min.

205 min.

Oil Retaining Properties

mm / # paper filters

JIS A 5751

7/1

12/2

12 max/5 max

Flowing Off Test, minutes @ 25°C JIS A 5758 > 360 > 360 > 30

Four Ball EP, kg weld D 2596 800 620 315 min.

Four Ball Wear, mm D 2266 0.63 0.89 0.90 max

Specific Gravity D 1475 1.158 1.162 1.15-1.25

Compatibility with sealing material,

volume change

D 4289 -3.32 - 3.70 NS

Biodegradability, % OECD 301B 75 NA NS

(*) B-TSC: Biodegradable Tail Seal Compound

(**) CA-TSC: Commercially Available Tail Seal Compound

(***) NA: Not available, (****) NS: Not Specified

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Figure 6: Fire Resistance Testing