Internal Letter oi% Rockwell Internationa lNo

MPR 75-742

FROM Chemistry b NonmetallicAddress Material s

D/590-175, ACIDPhone 2340

Subject CHEMICAL ANALYSES PERTINENT TO THE CONTAMINATION OF THE COCAFACILITY SYSTEM

TO C. G . FargoAaori D /598-340, SS1 l

0,11, 21 May 1975

Reference : (a) IL C . G . Fargo to Distribution, "Brief PreliminaryAccount of Acid Contamination in Coca 1 LOX System",dated 11 March 197 5

(b) SSFL - Analytical Chemistry Report, Reference LB-75-35,dated 27 February 1975 (Attached )

(c) IL D . C . Heim to J . H . Monaghan, "Chemical Attack ofCoca Test Area Temp Bulbs ", dated 1 April 197 5

(d) Unpublished Report by G . J . Bas], dated 10 March 1975(Attached )

(e) IL B . C . Neale to Wayne Taggart dated 17 March 1975(Attached )

(f) SSFL Analytical Chemistry Report, Reference LB-75-75,dated 27 February 1975 (Attached )

(g) SSFL Analytical Chemistry Report, Reference LB-75-61dated 26 March 1975 (Attached )

Attachment 1 - Rationale for the suitability of Coca 4 Oxygen SystemAttachment 2 - Certifications for all 6 In. pipe used In construction

DISTRIBUTIONof Coca 1

D/596-100 AC1 7G . A . Fairba rn

D/556 SS1 1C . G . Magness

D/590-175 ACIDJ . Bas l

D/598-344 SS11sch e r

D/598-343 SSiiA. G he ra rd i

D/598-348 SS11

J . H . Monaghan

D/522-199 SSI 1

S . FujikawaB . C . Neale BA71

BACKGROUND

On 27 February 1975, Materials and Processes was requested tosupport D/598 In the evaluation of contamination discoveredon 26 February as the result of failure in a 10" elbow duringa 180 psi leak test of the Coca 1 LOX system . The failure wascharacterized by leakage in the elbow which emitted a clearcolorless liquid (Reference (a)) . The resultant investigationdisclosed on the order of 120 gallons of the fluid trapped in theCoca 1 oxidizer system and led to a comprehensive search forcontamination not only in the Coca 1 oxygen system , but of allfluid systems on both the Coca 1 and Coca 4 test stands togetherwith associated transfer and dump lines . This investigation ledto the discovery of a number of anomalies which required analyticalsupport and materials evaluation . It is the object of this reportto present a summary of these analytical results and evaluationsand make comment where appropriate .

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Identification of the Fluid Found in the Coca 1 LOX Syste m

Preliminary analyses (Reference (b)) of the fluid found in the Coca 1 LOXsystem showed it to have an extremely low pH of one or less and a chloridecontent of from 120 to 160 ppm . A tentative conclusion was made at thistime that the fluid was hydrochloric acid and sulfuric acid (Reference (b)) .However, this was proven unfounded when subsequent analyses (Reference (b))revealed on the order of 15 grams orthophosphate (P04-) per 100 cc in thefluid and re-analysis for chlorides In this medium showed them to be between67 and 95 ppm . Quantitative sulfate ( S04-) analysis showed them torange from 68 to 112 ppm S04- (Reference ( b)) . A summary of these

results, together with the sampling points and general analytical techniquesused , is presented in Tables I and II .

Table Ii also shows the result of isopropanol analyses from the sample from thebulk storage line . This analysis was made to ascertain If the phosphoric acidhad been blended with phosphoric acid as is frequently done for cleaningsolutions . The magnesium analysis of the samples summarized in Table I werefor the purpose of aiding in the verification of the H3P O4 diluent as tapwater . This value coupled with the chloride and sulfate results indicatethat this was the case .

Effects of the Phosphoric Acid Solution on the Test System Material s

A review of the materials used In the Coca 1 test system coupled with anexamination of hardware removed from the contaminated system for refurbish-ment indicated only two of the components were subjected to damage by thephosphoric acid . They were the carbon steel bushings in the Hadley butterflyvalves and the ceramic coating on the temperature transducers . Three valves

were found to have bushings which had apparently been attached by thephosphoric acid . Using a portion of the acid solution taken from a lowpoint in the line to LOX bulk storage , a laboratory test was conducted on anew bushing in an attempt to verify that this solution would attack thecarbon steel and an approximate rate of the attack. It was found that therate of attack in the approximately 15% phosphoric acid from the bulk storageline was low, approximately 0 .0016" In two weeks as compared to a loss of0 .0434" In the bushing from LT 19 exposed to the phosphoric acid in thesystem . However , it was noted that when the solution evaporated to a syrupyconsistency, the attack rate significantly increased leaving a rough pittedsurface similar to that observed on bushings removed from Hadley valvesexposed to the phosphoric acid while In the system .

A rather comprehensive evaluation of the temperature transducer ( temp bulbs)failures is presented in Reference (c) ,

To ascertain the compatibility of residues from the contaminant with LOX,the testing shown in Table III was conducted . Based on these results, it is

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concluded that any residue from the phosphoric acid contaminant left in orintroduced into a LOX system would be compatible with LOX . Testing included

the impact testing of both the as is contaminant and a 10% concentrate of

the contaminant . Impact tests were done in accordance with MSFC-SPEC-106B .

Sensitization of Coca 1 304 CRES Lines

Because the ultimate failure of the Coca 1 elbow during pressure test wasattributed to sensitization (Reference (d)), considerable effort was expended

in obtaining filings for carbon analysis from all the critical oxygen line s

on Coca 1 . The bulk of the results of these tests and the problems of accomplish-ing them are reported in Reference (e) . Since publication of Reference (e) ,three more carbon analyses have been run . They were as follows :

Sample #42 .05,

%C

.04, .07(solid piece )

Sample #44 (filings) 0 .10, 0 .1 1

Sample #45 (filings) 0 .10, 0 .09

Samples #44 and #45, both taken from six inch Schedule 10 304 CRES lines were

the only samples not meeting the 0 . 08 maximum carbon content for this material

in the new construction of the Coca 1 test facility . Attachment 2 shows the

certifications for all the 6 inch pipe procured for new construction on Coca 1 .

It has been , therefore , concluded that the high results for carbon in Samples#44 and #45 were due to the sampling technique and difficulty of sample clean-

up prior to analysis .

The corrodents causing the intergranular corrosion of the sensitized elbow were

attributed in Reference (d) as being the polyeurethane foam and associatedchlorides, see Reference (e), on the exterior of the lines and the phosphoric

acid on the interior of the lines . It Is Interesting to note , however, that

exposure of a sensitized section of pipe cut adjacent to the failure has shownno evidence of attack after two months of exposure to the phosphoric solution

removed from the Coca 1 system .

Investigation of Coca 4 Systems

Because of an incident on Coca 4B at the time of the Coca I phosphoric acidinvestigation and in spite of the fact that the Coca 1 and Coca 4 systems

are reasonably isolated from one another , some component removals were made

from the Coca 4 system . Components removed included flow meters, temp

bulbs, servo valves and filters . Water extractions of a number of these

parts were then made and the effluents analyzed for a variety of ions,

e .g ., P04, N03-, F-, and Cl- . The results of these extractions on temp

bulbs were outlined in Reference (c) . Extractions on valves an d

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MPR 75-742

filters are reported in References ( f) and (g) . Though the main thrust ofthese tests was to ascertain the presence of P03 ; ions, small quantitiesof fluorides were detected on the surface of many components . Attachment 1presents a rationale for acceptance of the Coca 4 system in spite of thefluorides present . Flowmeter LB-66 on Coca 4B was also removed at this

time and , aside from some apparent burning at the vane tips probably dueto rubbing as a result of an anomaly in system operation , several rustspots and some pitting was noted on the rotor of the flowmeter . Electronbeam microprobe analyses of the rust on one of the vanes revealed trace s

of fluorine which did not appear on adjacent nonrusted areas . Considerationis now being given to electroless nickel plating or phosphate and treatingthe flowmeter roters .

During this investigation , flowmeter LB-66 was found to have approximately

154 inches of an 0 .050 wire entwined in the housing . Analysis of the wire

was as follows :

Cr 18 .5%N I 8 .45%C .06%S .013%

This analysis indicates the wire was either 302 or 304 CRES . The diameter

and analysis of this wire was virtually identical to the bearing retainer

wire used in Rocketdyne -designed ball valves . Subsequently , an identical

piece of wire was found in the LB 75 MCC oxidizer filter . This piece was

approximately 5 inches in length . Based on the above , an investigation

revealed the top retainer ring (25 .7 In . in length and 34 in . of the outer

cam upper bearing spring ) from a 6 Inch ball valve (OT-1) was missing . The

length of the former spring is slightly longer than the sum of the two pieces

found in the system . It is, therefore , apparent that two pieces (approx .

31 In . and 54 in . long ) not accounted for have been blown overboard .

Bonnet Seal Burnin g

During Inspection of the LB-77 LOX bleed valve on Coca 4B impressions on

nose cone were evident and it has been speculated that these may have been

due to the bearing wire previously discussed . This, however , has not been

verified . Disassembly of this valve revealed the Fluorocarbon TFE seal

along with the CRES spring had been about 90% consumed by burning . X-ray

diffraction analysis of the unburned seal material showed that it was TFE

Teflon . Previously melted metal from the seal cavity was Identified by

energy dispersive X-ray fluorescence as a 300 series CRES alloy . Magnetic

fragments high in iron and chromium identified In the same manner were an

oxide combustion product of the CRES spring . Carbon tetrachloride

extractions of the valve inlet and outlet , Internal surfaces of the bonnet

seal, the seal cavity , the bonnet guide cavity , and the bonnet guide sea l

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mating surface for hydrocarbon cleanliness were also made. Similar extractions

were made on a spare unused valve and two seals , one from the spare valve and a

second from a new spare seal . The results of these extractions were as follows :

LB-7 Spare Valve Spare Sea l

Valve Inlet & Outlet 1 .8 mg/ft2(1) Ni l

Separator TubeInternal Surface

Bonnet Seal Cavity

Bonnet Guide Cavit y

Separator TubeBonnet MatingSurface

0 .2 mg/ft2(2 )

Ni l

Ni l

Nil

Ni l

Ni l

Ni l

Ni l

Bonnet Seal - 1 .6 mg/ft2(2)(3) 1 .6 mg/ft2(2)(3 )

(1) Extrapolated from 1 mg hydrocarbons(2) Extrapolated from 0 . 2 mg hydrocarbons(3) Ultrasonic cleaned

During removal of the separator tube from the valve assembly , some difficulty

was encountered due to an interference between the separator tube and the

valve stem . This resulted from large dents in the separator tube and caused

the removal of the separator tube , the upper and lower stem , guides and the

stem packing to be removed forcibly. This resulted in severe galling of the

bonnet guide carrier and the stem guides . Because much of the galling occurred

opposite the burned bonnet seal some concern was expressed that overheatin g

in this area may have resulted in the seal burning . However , a careful

examination of this area showed no evidence of heat discoloration on the bonnet

guide carrier and small points discoloration In this area proved to be small

fragments of CRES, probably 321, and bronze , probably from the stem guides .

These analyses were conducted by energy dispersive scanning electron micro-

scopic analysis and the particles were probably the result of the galling

between separator tube and bonnet stem .

J . H . deb, Manager

/ Chemistry & Nonmetallic Materials

W . A. Taggart Materials and Processe s

JHL:WAT :cb

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TABLE I

CHEMICAL ANALYSES OF LIQUID FROM THE COCA 1 OXYGEN SYSTE M

SAMPLE LOCATION

NITRATES FLUORIDES- CLORIDES SULFATES PHOSPHATES(N03

) pH (F-) (Cl-) (504-i (P0e )

ppm pp`m ppmppm g/lOOc c

Vertical Section of < 10 1 < 0.1 73 112 15.05

Franz Screen (CT-67 )

Tank 40

LOX Transfer Duct < 10 1 < 0.1 78 68 14.66

Downstream of Failed Line

Downstrear of Valve LA-13 - < 10 < 1 < 0.1 91 74 17.12

Coca 1A LOX Discharg e

Isolation Valve

Temporary LN2 Fill Line - 0.7 93 100 19.34

at Check Valve Join t

Sample I

Same as Above - 0.7 95 100 19.21

Sample 11

GENERAL ANALYTICAL TECHNIQUE S

NITRATES - Specific ion electrode without standardization in phosphate matrix

FLUORIDES - Specific ion electrode without prior distillation from phosphate solution

CHLORIDES - Specific ion electrode from phosphate matrix (standardized )

SULFATES - Barium sulfate turbimetric metho d

PHOSPHATES - Ammonium molybdate precipitation- back titration

TABLE I I I

CHEMICAL ANALYSIS OF CONCENTRATED FLUI D

Sample - Vertical Section of Franz Screen (CT-67 ) Tank 40

Evaporated to approximately 10% of Volum e

Boiling Point of Solution 150 C

High - Phosphorous Content (X-Ray Fluorescence )

Evidence of Iron, Chromium, Nickel Potassium, and Calcium (X-RayFluorescence)

No Evidence of Hydrocarbons ( infrared )

CHEMICAL ANALYSIS OF WETTING AGENTPURPORTED TO BE USED BY THE CONTRACTORAS AN ADDITIVE TO PHOSPHORIC CLEANINGSOLUTIONS ( ROHM + HAAS DF-18 )

Strong Hydrocarbon Absorption by Infrare d

LOX IMPACT TESTING OF FLUID

Sample from low point In line to bulk storag e

1 . As received 0-20 @ 72 foot-pound s

2 . Concentratedto 9% of Volume 0-20 @ 72 foot-pound s

Testing In accordance with MSFC-SPEC-106B

M?R 75-74221 May 1975

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ATTACHMENT 1

RATIONALE FOR THE SUITABILITY OFCOCA 4 OXYGEN SYSTEM

Milligram quantities of Inorganic salts have been analytically detectedon the surface of a number of components in the Coca LOX systems at SSFL .Although a number of chemical species were detected in the course of theanalyses associated with the Coca 1 contamination problem in which theprima ry emphasis was on the determination of phosphates , it was noted thatva rying amounts of water soluble fluorides were being detected . Varyingamounts have been found on several Coca 4 temperature bulbs , filters andon the 9310 steel rotor of the OPB LOX flowmeter . Their source is currentlyonly speculative . However , because ( 1) they have been found in relativelylow levels , (2) there has been no corrosion associated with the presence ofthe salts with the exception of the OPB LOX flowmeter impeller, ( 3) inorganicsalts are compatible with oxygen , and (4 ) there have been no visibleparticulates associated with the salts , their presence is not considereddeleterious to either the facltlty system or the components which wil lbe tested on the system .

With respect to the rust spots and pits found on the above flowmeter, awater soluble fluoride has been identified in the corrosion product on oneof the impeller vanes . It Is recognized that in the presence of somefluoride salts, corrosion of low alloy steals such as 9310 may beencountered . However, subseq+'ent to the drying of LOX systems in whichthe fluorides have been detected to a dew point of OF, rigorousmoisture contro l will be implem.nted and will Include continuous purging(or other mositure control techniques) of systems when opened for anymodification or component replacement . Since moisture must be presen tto initiate corrosion even In the presence of the most potentially corrosivesalts on corrosion susceptible alloys , the above procedures will obviatethe possibility of corrosion as the result of the presence of fluorides .

It is not likely that the source of the salts can be determined with anydegree of certainty , even with extensive analysis , because of the ve ry smallamounts of material involved . The largest amount of fluoride found wasonly 38 milligrams found In the large filter U/S of SA-2 . Because theanalytical technique required water extraction of the entire filter, itcannot be determined if the amount determined was the result of one or afew places of fluoride salt or the result of some processing operation whichleft a more or less uniform fluoride deposit over the entire surface .

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