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!2xaQua Sam Bose

Northrop Grumman Corporation One Northrop Avenue, 3220D

Hawthorne, Ca 90250-3277 (310) 332-7886

(310) 332-1787 (Fa)

Water Soluble Lubricants for Tube Bending and Cleaning Methodology

Abstraa: Current Federal and State regulations require stringent air quality emission

standards for air toxics and ozone depleting chemicals. The use of 1,l.l trichloroethane (TCA) vapor degreasing has been a key metal finishing process in aerospace and other manufacturing industries. As mandated by various regulatory compliances and Northrop Gru"an Military Aircraft Division (NGMAD) Corporate Directive, the use of 1,1,1 trichlmthane (TCA) vapor degreasing must be eliminated from Northrop Grumman facilities by the end of 1995. As a compliant degreasing material, alkaline aqueous &greaser Brulin 815GD was selected as a replacement for vapor degreasing. Although machined and formed sheet metal parts are being successfully degreased using compliant cleaners, tube cleaning offers significant challenges because of the complexity of various cofligurations, sizes and bends. Test results showed that it was not possible to clean/ remove currently used tenacious lubricantkontaminant from the inside surface of tubing using conventional fluid agitatiodflow methods. Several approaches were taken to determine optimum cleaning methods and equipment systems. These methodologies included an industrial agitator, manifold system, fluid flow and ultrasonics. Substantial progress has been made in empty tube bending process. The present work led to the evaluation of water soluble lubricants which would be compatible to the compliant aqueous degxcasing process. Based on the test results three water soluble lubricants were selected for tube bending, flaring and swaging. Further investigation led to the integration of basket/tubes "vertical oscillation motion'' methodology forcleaning tubes using aqueous &greaser. Cunently, the aqueous degreasing cleaning system for tube cleaning is being implemented in production.

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control#39 Sam Bose

Northrop Grumman Corporation One Northrop Avenue, 32”

Hawthorne, Ca 90250-3277

(310) 332-1787 (Fax) (310) 332-7886

Current federal and state regulations establish stringent air quality standards for air toxics and ozone depleting chemicals. Due to the ban of 1,1,1 TCA, reduction in production by manufacturers and Corporate Directive, NGMAD is in the prpzess of nplacing all vapor degreasing operations with an environmentally compliant process by December 1995. Vapor degreasing of formed tubing is one of the processes identified for such replacement.

NGMAD currently uses Titanlube 1129 for most of the bending operations for F-18 subsystem tubes consisting of hydraulic, fuel and pneumatic lines. In some cases, Aldraw J-2 is used for bending thick walled titanium tubes. As a compliant material, alkaline aqueous &greaser Brulin 815GD was eduated for tube cIeaning. Although machined and formed sheet metal parts an? being successfully &greased utilizing compliit cleaners, tube cleaning offers significant challenges because of the complexity of various configurations, sizes and bends. Tube cleaning program at NGMAD was initiated in 1991 with an industrial agitation system. Tests showed that currently used petroleum based lubricants CM not be cleaned using aqueous &greaser with conventional fluid agitatiodflow. Several approaches were taken to determine optimum cleaning methods and equipment systems. These methodologies included an industrial agitator, manifold system, fluid flow and ultrasonics. Other altematives that were evaluated included empty tube bending and water soluble lubricants. The present work led to the evaluation of water soluble lubricants which would be compatible with the compliant aqueous degreasing process. An industry survey was also conducted by NGMAD concerning the use of aqueous degreasing processes for tube cleaning. The survey showed that water soluble lubricants are commonly used for tube bending whenever aqueous degreasing was employed. NGMAD decided to continue testing to validate the water soluble lubricantkqueous degreasing for production use.

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!2x" Sam Bose

Northrop Grumman Corporation One Nonhrop Avenue, 3220/09

Hawthorne, Ca 90250-3277

(310) 332-1787 (Fax) (310) 332-7886

Preliminary Aqueous Degreaser Cleanability Tests In this phase of the test program, the aluminum test panels coated with the selected

lubricants were cleaned with Brulin 815GD aqueous &greaser, rinsed with DI water and were inspected for water break free surface. A flow chart showing the cleaning process is shown in Figure 1. All test coupons showed water break free conditions after aqueous &greaser cleaning and rinsing.

Preliminary Tube Fabricadon Eval&n

The test results ofthe preliminary tube fabrication evaluation are shown in Tables 1 & 2. Prequalifcation test results on the selected six water soluble lubricants showed that Masterdraw 1767C provided best results for aluminum, titanium and Cres tube bending. Houghtodraw 7007 was also found suitable for bending aluminum, titanium and Cres tubes. Masterdraw 1872 was found suitable for bending Cres tubes. Masterdraw 1767C and Houghtodraw 7007 lubricants are liquid form. Masterdraw 1872 is in paste form. Since a lubricant in paste form is more difficult to be applied on the inside surface of the tube, it was decided to select only Masterdraw 1767C and Houghtodraw 7007 for qualification tests.

Tube f&rica.!ion,flaring and swaging

In the qualification tests, tube bending configurations (angle of bend, radius of bend, no. of bend and direction of bend) were selected based on production parts. The formability of the tubes were evaluated per McDonnell Douglas Aircraft (MDA) Process specifications ( PS) PS14010 and PS14010.1. Representatitive data for tube bending are shown in Table 3. The test results demonstrate excellent forming characteristics using Masterdraw 1767C and Houghtodraw 7007 lubricants.

Conversion coated aluminum tubings were flared per PS14008. Swaging of conversion coated aluminum tubes with Wiggins and Dynatube fittings were done per PS17146 and PS17146.1. Swaging of titanium tubes were done with Dynatube fittings. The qualification test results for tube bending, flaring and swaging are summarized in Table 4. Masterdraw 1767C was found to be best lubricant for tube bending, flaring of aluminum and swaging of titanium tubes.

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i2u” Sam Bose

Northrop Grumman Corporation One NO-D Avenue. 3220/09

Tube Clean’ng Tests :

0 vertical Oscillorion

In this phase of the test program aluminum, titanium and Cres tubes that were bent as shown in Table 3, were evaluated for cleanability following aqueous degreaser cleaning. All tubes were cleaned for 15 minutes in 15% Brulin 815GD aqueous degreaser solution at 1WF temperature using vertical oscillation. The tubes were then rinsed in DI water for 5 minutes at 120’F using vertical oscillation. The final rinsing was done in DI water at room temperature for 1 minute using vertical oscillation. The tubes were then dried in oven at 1WF for 30 minutes. Visual examination of the tubes did not show any contaminants. The tubes were sectioned longitudinally and were visually examined for cleanliness. No contaminant was found and the cleaning criteria per PS14010 and PS14010.1 were met. Some titanium tubes lubricated with Masterdraw 1767C were checked for non-volatile residue (NVR) and the cleanliness level met MIL-STD-1246B level A.

Aluminum tubes that were aqueous degreased were alkaline cleaned, deoxidized and conversion coated per process sequence shown in Figure 2. The cleanliness of the tubes was acceptable for conversion coating per PS 13209. (2) Manifold Cleaning

3/8” and 1/4” &a. Cres and titanium tubes bent with Masterdraw 1767C and Houghtodraw 7007 lubricants were cleaned using manifold system with Brulin 815GD aquceus degreaser and D. Lwater rinsing. The fluid flow was set to attain minimum 2.0 ft per sec. velocity through the tubes. Inspection of the sectioned tubes showed that cleaning criteria per PS 14010 and PS 14010.1 were met.

In this phase of the program, corrosion testing was conducted to validate the adequacy of replacing vapor degreaser with Brulin 815GD aqueous degreaser in the chemical conversion coating process for aluminum tubing. Straight aluminum tubing with and without fittings that were processed per Figures 3 and 4 were submitted for 5% salt spray testing. The test results are shown in Table 5. Test requirements for 5% salt spray test in Bccordance wth ASTM B117 per PS 13209 were met.

As per current practice in production, tubings will be aqueous degreased upto a maximum of three times following conversion coating. The concem was whether there was any detrimental effect of aqueous &greasing on the conversion coating.

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control#39 Sam Bose

Northrop Grumman Corporation One Northrop Avenue, 3220/09

Hawthorne, Ca 90250-3277

(310) 332-1787 (Fax) (310) 332-7886

Salt spray corrosion tests were carried out on conversion coated aluminum tubes after aqueous degreasing three times. The process sequence is shown in Figure 5. The test results showed that corrosion resistance of 5052-0 and 6061-T4 aluminum alloys is not degraded. All aluminum tubing materials at NGMAD consist of 5052 and 6061 alloys. Therefore, aqueous degreasing of conversion coated tubes is acceptable which meet the requirements of MIL-C-5541.

Compatability / recyclability evaluation of Brulin 8 15GD aqueous degreaser solution with tube bending lubricants and also with tube shop soils were conducted. Lubemix 1 is a formulated mix of the three qualified water soluble lubricants. Lubemix 2 is a formulated mix of the three water soluble lubricants along with VVL-800, Mobil light oil and MLH-5606 hydraulic fluid. The test results (Table 6) show that water break free conditions were achieved until the contaminant loading is 230 gms/gallon using Lubemix 1 and is 250 gms/gallon using Lubemix 2. Recycling evaluation using ultrafiltration demonstrated that Brulin 815GD aqueous degreaser with the water soluble lubricants is recyclable by ultrafiltration. However, the loss in Brulin concentration after ultrafiltration has been as high as 14 - 22% at the end of 10 hours of ultrafiltration using bench scale set- UP.

The tube cleaning system was incorporated in the advanced manufacturing center (AMC). Provision was made for two step process. The aqueous degreasing process line consists of Brulin 815GD aqueous degreaser tank, hot DI water rinsing tank, cold DI water rinsing tank and Brulin 815GD alkaline cleaning tank. Cascading system was added to the DI water tanks. The Process Instrumentation ( PI ) diagram for the Brulin 815GD aqueous degreaser tank is shown in Figure 6. An eductor agitation system sets the motion of the upper portion of tank solution towards the weir. The free or floating oil is collected in the weir tank. From time to time, the oil in the weir tank is pumped out. An automated Ultrafiltration unit has been incorporated in the tube cleaning system.

The crane has an automatic carriage oscillation mode with a programmable controller. The programmable controller is capable of changing adjustable vertical upper and lower travel limits, variable vertical travel speed, variable dwell time periods at lower and upper limits of Vertical travel and variable oscillation cycling time period for each tank.

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l24" Sam Bose

Northrop Grumman Corporation One Northrop Avenue, 3220/09

Hawthome, Ca 90250-3277 (310) 332-7886

(310) 332-1787 (Fax)

The average speed of automatic oscillation of the basket is programmed at 0.8 ft./sec. When the basket is raised above the tank solution, it is held for five seconds to allow the liquid to drain from the tube. The dwell time of the basket immersed in the aqueous degreaser is 15 seconds. The aqueous &greasing cycle is for a period of 15 minutes. The hot DI water rinsing cycle time is for a period of five minutes and the cold DI water rinsing cycle time is for a period of one minute. Figure 7 shows a basket containing tubes is being cleaned by vertical oscillation. A wand system has been incorporated in the tube cleaning system. The wand will be used for flushing the inside of the tubes only in limited cases.

As a result of positive test results, three water soluble lubricants - Masterdraw 1767C. Houghtodraw 7007 and Masterdraw 1872 were selected for tube bending operation in conjunction with Brulin 815GD aqueous &greaser. Aluminum, titanium and Cres steel tubes can be bent without drag, collapse, slip or breakage using Masterdraw 1767C and Houghtodraw 7007. Visual examination and Nonvolatile residue results showed that the inside surface of the tubes were clean. Conversion coated aluminum tubes were successfully flared using Masterdraw 1767C. Houghtodraw 7007 and Masterdraw 1872. Conversion coated aluminum tubes with Dynatube fittings were successfully swaged using Masterdraw 1767C and Houghtodraw 7007. Conversion coated flared and swaged aluminum tubes along with conversion coated straight aluminum tubes without flaring and swaging were processed using Brulin 815GD aqueous degreaser. All the tubes passed the 5% salt spray test per ASTM 117 to the requirements of process specification.

The saturation point at which Brulin 815GD aqueous degreaser loaded with water soluble lubricant attains water break condition is high. Brulin 815GD aqueous degreaser loaded with water soluble lubricant was found to be recyclable by uluafiltration. The tubes that were bent with water soluble lubricants can be cleaned successfully using Brulin 815GD aqueous degreaser and vertical oscillation method which meets cleanliness requirements per current specifications. However, some of the tubes with very complex bend configuration may need flushing in addition to cleaning by vertical oscillation method. The corrosion testing by salt spray test also established the adequacy of replacing vapor degreaser with Brulin 815GD aqueous degreaser in the chemical process for aluminum tubing. The tube bending and tube cleaning methodology have been approved by MDA for F-18 subsystem tubes consisting of hydraulic, fuel lines and pneumatic lines. The tube cleaning system using vertical oscillation and Brulin 815GD aqueous degreaser has been installed. NGMAD is currently in the mode of implementing the tube cleaning operation using water soluble lubricants for tube bending and Brulin 815GD aqueous degreaser for tub cleaning.

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l2l"! Sam Bose

Northrop Grumman Corporation One Northrop Avenue, 3220109

Hawthome, Ca 90250-3277

(310) 332-1787 (Fax) (310) 332-7886

The authors dedicate the publication of this paper to the memory of late D. C. Unruh who has contributed significantly towards the tube cleaning system. The authors thankfully acknowledge A. P. Wijenayake, Manager, Manufacturing Assembly Process and Surface Finishing Technology department for the support and encouragement provided for this work. Thanks are due to members of Man-Tec Surface Finishing Technology, AG tube operation group, M 8r P and Waste Minimization departments for the help provided for this work. Salt spray corrosion tests were performed by M&P department.

control#39 Co-author: N. T. Thomas

Northrop Grumman Corporation One Northrop Avenue, 3220I09

Hawthome, Ca 90250-3277 (310) 332-6649

(310) 332-1787 (Fax)

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3~3~X0.050" ,6061-T4 ALUMINUM COUPON

CONTROL

I VAPOR DEGREASE, PS 12020

ALKALINE C t EAN. PS 12030

I DEOXIDIZ8, PS 12050.1

IESI

BRUSH-ON TEST LUBRICANT, AGED, ROOM TEMPERATURE, 24 HOURS MIN.

IMMERSION CLEAN IN BRULIN 81 5 l D AQUEOUS DEGREASER. 160 +I- 5 'F. 15 MINUTES WITH AGITATION

t t

IMMERSION RINSE WITH AGITATION, 5 MINUTES, 120 'F(DI WATER)

IMMERSION RINSE WITH AGITATION, 1 MINUTE, ROOM TEMPERATURE (DI WATER)

REMOVE COUPON AND INSPECT SURFACE FOR WATER BREAK FREE (WBF)

NOTE : LUBRICANT REJECTED FOR FURTHER TESTING IF WBF IS NOT OBTAINED AT LAST RINSE

I 1 I

I I I I I I I I I I I I

F E Preliminary Cleanabity Test Sequence

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PRE-QUALIFICATION AND QUALIFICATION SEQUENCES FOR TUBE PROCESSING

Lub.d VapW UWl"e DIP Rinse Spray Rinse i " S W spd" O * l W S Clean Tap HDI Tap Rmm Temp. WBF Dwxidim

- PS 12050.1

men DV. Spray Rinse. DIP "8. CO"YBRi0" Spray Rlnse. Olp Rlnss. 1 4 0 k 0.1. Rmm 0.1. Rmm Coal 0.1. Rmm Tap R"

Temp. Temp. PS 13209 Temp. Temp.

SPECIMEN PREPARATION PROCESS SEQUENCES FOR TUBINGS

spdmn w- C h 0.1. H d Rmm Tmrrp. WBF D.o"idh. L h d V W A M " . Dip R i n ~ . Spray Rinu. 0.1. I " W

Lub.d Blvh 0.1. Hol cold 0.1. Brv5" 8,550 Do Rlnw

9

FLARED AND SWAGED TUBING PROCESS SEQUENCE FOR TESTING

CHEMICAL CONTROL CONVERSION

(VAPOR DEGREASE) COATEDNSING SEQUENCE ( C W

(Note 1) swage on VaPW CCC To"*. MI spray Flmq Dqrease. up, PS 13204 Test

PS 14010 PS 1" Aped. 24 hm., R.T. Mlnlmum

CHEMICAL TEST CONVERSION

(BRULIN COATED TUBING SEQUENCE (Note 2)

" 1. Tubing processed in normal production

sequence to this point.

2. Tubing processed to this point uses Brulin 815GD replacing vapor degrease.

Set #1 (Control) Processing Sequence: B d i 815GD Aqueous Degrcase

per P.S. 12024

Salt Spray Test

swage 00 Flmng

PS 14010

Biulln 815GD DI Wafer DI Water doom Temp. Aqumus Hotolp Sprey DqreSSe Rlnre Rlnse

lnspecr WBF

salt Spray Toum-up. oven Dry Teal CCC PS 13204 14O'F

Aged. 24 hm, R.T. Mlnlmum

Set #2 Prorrssing Sequence:

1 Aee panels for 24 houn at ambient conditions

B r u l i 815CD Aqucous Degrease per P.S. 12024 hen oven dry at

135 +/- 5'F for 30 minutes

per P.S. 12024 Ihm oven dry at

pcr P.S. 12024 hen oven dry at

Salt Spray Test

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PRELIMINARY TESTS n 1

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SUMMARY (

Supplier

Tower Technology

hughion

w i tm

Alcchem Atcchem

Tower oil 8 Tech.

Dubois/Diversey

C a s "

Houghton

Atcchem

Dubois/Diveney

lnlernalional Lubricant

Pelmlube

Chemtool

Innovalive Organics

S8S Industrial Services

ETNA Products

TEST EVALUATION

Lubricant

LS-8-OSH Klendraw-4100 Klendraw-4166

Houghtodraw-7007

Lusoi-81

SDO-7K80 SDC-7434

A-108 A-1 24 TC-88

TC-89 TC-99 G-9105

Supersiam

Meqqem 8506 377 x-51 X-52

Houghton 1687-207-01 Houghlon 3108

SDC-7434

Superslam

Lubeguard

PL4100HD DC 2418

CT 3307

Amberlube EP Amberlube SP

Cooilube 5008

Masterdraw 81767C Maslordraw 81872

I WATER SOLUBLE LUBRICANTS

Remarks

Failed in lube bending * Failied in tube bending - Failed in tube bending

Falied In lube bending (SS-1 1/T x ,028" I. R.B. Y), othetwise promising

- Failed in tube bending. Better than LS-8-05H. Kiendraw -4100, Klendraw-4166.

Failed in sandwich corrosion test * Failed in tube bending tests

Chlorinated, unsuitable . Chlorinated. unsuitable - Passed in sandwich corrosion test. Initially, Mfg. preferred not to use paste for tube bending. Failed in tube bending tests. Failed in sandwich corrosion

* Failed In sandwich corrosion Failed in sandwich corrosion

Failed in sandwich corrosion

- Failed in tube bending Tesls not complete - used with 25% D.I. water

* Failed in lube bendlng -used w/20% D.I. water - Failed in lube bending

Failed in tube bending * Failed in tube bending

Failed in tube bending

* This malerial failed in sandwich corrosion tests earlier in1993. Also, failed in sandwich corrosion tests by Boeing. Tube bending was not pursued by Man-Tec. Failed in recent tests on tube bending.

* This material is in paste form. Since, in the pasl, Mfg. preferred no1 lo use paste for tube bending. Man-Tec did no1 pursue testing this material. Limited tube bending tests done so far. Failed in tube bending tests.

Vefy good candidate * Very good candidale

Umited tests have been done so far

* Good candidale Failed in tube bending

* Failed in tube bending

Limited tests were done in 1993 Umited tests were done in 1993

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P

................ I ....................... I ..............

.................................................... ss yB-X.WP - 60610 1 1 1 2 r . D W F

..................................

R B . - l l P .................................................... li- w.012 P

RB.-17.W . . . . . . ~ ~

Tluurn 1.. .OW P RB. - 2

50524 1-x.ms- P ......................................

R a - t m ......................

60614 1 W X . W F P RB.. r

. . . . . . . . . . . . . . . . . 60614 2s.m - IRn.-* . I ...............................................

6c61.1. lIC..WS* R 8. - IN.

5mnjaruum l'i .051* RE. - r . . . . . . . . . . . . . . . . .

manium 1-x.rmr

............................................ 50520 Z l I 2 X . w s

RB. - C .................................

li" SnrX.OlS' R B . - 1 l P

u u

YEMBi - P

.............. P

.............. -

........... -

.............. P

.~ P

.............. -

.............. F

.............. F

. . . . . .

. . . . .

............

..............

.............

. . . . .

. . .

.............

-

PRELIMINARY TESTS TUBE BENDING EVALUATION USING WATER SOLUBLE LUBRICANTS

..............................

............................... ID. BEND

!!.blQ& ................. (+) Bend ready

........ .... 0 s0rM Challeii ...............................

............................... r) some Chaffering - .....................

...........

...............................

............................ r) Limedrag (") Excell

rPasm.ic."~,m

D Parredmm

.............................

mllw wish msr&d ...............................

n Qualification Tests for Tube Bending - Vertical Oscillation Cleaning - Representative Data -

Qualification Tests for Tube Bending, Flaring and Swaging - SUMMARY -

Lubricant

. Masterdraw 1767C

- Houghtcdraw 7007

Masterdraw 1872

d m

Bending

Tests)

h?s

J

J

J

Bending (Quallflcatlon

Tests)

Al

J

J

Tube bending meets requirements per PS 14010 8 PS 14010.1

Flaring (Ouallflcatlon

Tests)

I i

Tube flaring meets reauirements r PS 14008. .

Swaging (Ouallflcatlon

Tests1

Tube swaging meets requirements per PS 17146 8 PS 17146.1

Remarks

L/qu/d Form - Best lubricant for bending. Recommended for tube bending, flaring of aluminum and swaging of titanium tubes.

Llquld Form - Recommended as back-up lubricant for tube bending. flaring of aluminum and swaging of titanium tubes.

Paste Form - Recommend for flaring and swaging of aluminum alloy tubes.

w J = acceptable x = wrinklespresent

in some AI alloy tubes

Water Soluble Lubricant

Masterdraw 1872

Braycote 236 r)

Masterdraw 1767

Manlube 1129 r)

Houghtodraw 7007

r) Control

Soil

Wlgglns Flaring Fitting Fitting

6061 -T4 6061-T4 1 llr. r, 2 1/2" 3/8", 1/2", 5/8", 314"

6061-T4 1 llr, 2", 2 1l2"

6061-T4 3W. 1/2", 5/8", 314"

6061-T4 38*, 112". 5l8", 314"

6061 -T4 3/8", 1l2", 5/8", 314"

Soil Mix

6061 -T4 112"

6061-T4 112"

Water Break Free

Water Break

6061 -T4 5052-0 112"

6061-T4 5052-0 112"

Water Break Free

Masterdraw 1767C 73% Masterdraw 1872 p/o Houghtodraw 7007 25%

Loss In Brulin 81 5GD Concentration After Ultrafiltration For 10 Hcurr

Mil-H-5606 Hydraulic Fluid

Masterdraw 1767c Masterdraw 1872 Houghtodraw 7007 VVL - 800

Straight I Tube Dynatube

22.5% - Pilot Process Tank 145 - Bench tank

5052-0 112"

22.5% - Pilot Process Tank

I

ialt Spray Results

Passed

Passed

Passed

Passed

Passed

-5% Salt Spray Test (ASTM 8117)

"Lubemix 1 " "Lubemix 2" I

I 230 GmslGallon I 21 0 GmslGallon

I ~~ ~

250 GamslGallon I 250 GmslGallon

I At End Of 1 Hr. Of Ultrafiltration I At End Of Of Ultra,iltration

Pi& Process Tank : 55 Galbns Ultrafiltration Membrane Pore Sue : 20 Tank Volume Changes Per hour

17 Recyclabillty/Compatability Evaluation of Brulin 815GD Aqueous Degreaser