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(NASA-['_I-_IWz_) LOx/GOX RZLA'I£D FAILURES NSl-27192
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NASA TECHNICAL
MEMORANDUM
NASA TM-82424
LOX/GOX RELAED FAILURES DURING
SPACE SHUTTLEMAIN ENGINEDEVELOPMENT
By C. E. Cataldo
Materials & Processes Laboratory
May 1981
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NASA
George C. Marshall Space Flight Center
Marshall
Space Flight Center, Alabama
M_P'C • Foem I1_(1 (R-v Ju,m_ 1_71}
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TECHNICAL REPORT STANDARD TITLE PAGE
12.
1- NREAPOSRTA TNOM. -824Z4 I GOVERNMENT ACCESSION NO, 3. RECIPIENT'S cATALOG NO,
4. TITLE AND SUBTITLE 5. REPORT DATE'
Lox/Gox Related Failures During Space Shuttle Main Engine October 1980
Development 6 PERFORMING ORGANIZATION C(OE
EH01
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORt" #
C. E. Cataldo
9. PERFORMING ORGANIZATION NAME ANO ADDRESS io woRKONIT_,0.
George C. Marshall Space Flight Center
Marshall Space Flight Center, Alabama 35812
I 1. CONTRACT OR GRANT NO.
_3. TYPE OF REPORT & PERIOD COVERED
12. SPONSORING AGENCY NAME AND ADDRESS
Technical Memorandum
National Aeronautics and Space Administration
Washington, DC 20546
14. SPONSORING AGENCY CODE
15. SUPPt._ENTARY NCTES
Prepared by Materials &Processes Laboratory
Science & Engineering Directorate
16. ABSTRACT
Specific rocket engine hardware and test facility system failures are described
which were caused by high pressure liquid and/or gaseous oxygen reactions.
The failures described were encountered during the development and testing of the
Space Shuttle Main Engine. Failure mechanisms are discussed as well as corrective
actions taken to prevent or reduce the potential of future failures.
17 _E _ W2oCS 1,_ DtST_'_ 14_ IL_N CTATEL4_-NT
l'nclas:_ified - ITnlimited
_9 ",rCCnlrY _t aSSl_.lof*hl_ r,,p,'e_) 20 _F'.L'_ITY CLA5 IF. _.4thll pale; 21 NO, OF PA(,[S 22 PRICE
Unclassified I'ncla.qsifled 79 =NTIS
M_F( . F_e,-, 12q2 rM_lv Iq_ql
TABI,I,: (ll, {'I)N'I'I,:XTS
INTRODUCTION ............................................... 1
FAILURE HISTORY ............................................. 2
FAILURE DESCRIPTIONS ....................................... 2
DISCUSSION ................................................... 20
PRE:CEDING PAGE BLANK NOT
lli
LIST OF ILLUSTRATIONS
Figure Title Page
I Coea 4B Test 014 .................................. 23
2 Isometric Schematic C4B Oxidizer System ............ 24
3 Coca 4B Ox. P/B F/M Lox Bleed ................... 25
4 Coea IA Simplified Schematic of Test Hardware ..... 26
5 Coca IA Test Set Up - LPOTP Not Shown ........... 27
6 Annin Throttling Valve (SA-5 Type) ............... 28
7 Annin Valve SA-5 - Post Test ..................... 29
8 Coca 1A Facility Flowmeter LA71 - Post Test ....... 30
9 Coca iA Facility Flowmeter LA71 Retaining Ring-
post Test ........................................... 31
10 Blade Root of Leading Face of Trailing Blade ........ 32
11 Schematic of HPOTP ............................... 33
12 High Pressure Oxidizer Pump Inlet Duct ............ 34
13 High Pressure Oxidizer Pump Dischari,re Duct ....... 35
14 High Pressure Oxidizer Pump ....................... 36
15 Configuration of the Primary Seal Area of the IIPOTP
and the Associated Materials of Construction. ........ 37
16 Coca IB Test 018 System Schematic ................. 38
17 SB-I Valve Seat and Stem Assembly ................. 39
18 Burned Valve Body ................................. 40
19 SSME 0004 After Test 136 Showing |)nmage to IIPOTP 41
20 High Pressure Oxygen Turbopump ................. 42
21 Cross-Sectional Drawing of High l'ressurc Oxidizer
Turbopurnp After Fire Showing Area of Damage ..... 43
iv
LIST OF II,I,USTRATIONS (CONTTNlyl,]I))
Figure Title Page
22 HPOTP Bearings ................................... 44
23 Injector and I,ox Posts ............................. 45
24 Main Injector 0002-1,ox Post Failure ................. 46
25 Deformation of I,ox Posts ........................... 47
26 Post Tips and Injector I"ace ........................ 48
27 HPOTP 0301 Burn Patterns ......................... 49
28 Capacitance l)evice ................................. 5g
29 Assumed Rubbing Mechanism ........................ 5l
30 High Pressure l)uct System ......................... 52
31 l:low (;uide in l)uct Showing' !_urm_¢t Region ......... 53
32 i]urne(l Region at I11si(le ,ff ]:lo,.v (;ui_le ............. 5,t
33 Close-Up of Burned Rc_ion ......................... 55
34
Inner Surface of Dye Penetrant Treated Flow Guide
at Region of Burned Crack ......................... 56
35
Inner Surface of Dye i'en(;trant "l'rc_,l;_(I Flow (]tlide. 57
36 SSME Powerhe:l¢t Schematic ......................... 58
Q
37
tleat Exchanger Ass(,mlflv l)arn:Jg',_ ................... 59
38 Heat Exchanffer Coil Removed from Assembly ........ 60
39 Internal Section ,)l' PreblJrn_,r wall an(I I_r_,,(l
lIEN (;f_ils ......................................... 61
40 Prel)urn,,r liner ,n,l Manit'¢,l(I I):_m;l!.,.. ............... 1;2
41 tleat l';xchan_er Assembly, l'reburnor I,iner
and Iloll¢_w._ ......................................... 63
42 Overall View of the l.;n_,,'in,, Sht,wing the llil,ql
Pressure Oxidizer l'uml_ .,\tea. an,I the Missing Pump
Discharge l)lmt and M:,in ()×idizer V',lve. ............ 64
• -" . 8
IAST O1: II,I, USTRA'FI(')NS ((;O}_'I'INI!!:,I_)
Title Page
Figure
43 MOV & HPOP Discharge Duct As Found In the
Flame Deflector Spillway ............................ 65
44 SSME Main Oxidizer Valve Assembly ................ 66
45 Origin Of Fire .................................... 67
46 Inlet Sleeve Removed From the Burned MOV ....... 68
4, Unburned Sleeve .................................. 69
48 MOV Inlet Liner & Bellows Assembly Removed From
Another Valve and the Evidence of Severe Fretting
in the Flange Area ................................ 70
49 MOV Cross-Section ................................ 71
50 MOV KeI-F Ball Seal Configuration ................. 72
51 MOV Kel-F Seal From Engine 0201 Test ............. 73
vl
"FECI1NICAI, MI',_I() RAN l)liM
LOXIGOX RELATEDFAILURES DURING
SPACESHUTTLEMAIN ENGINEDEVELOPMENT
SUMMARY
The various types of Iox/gox related failures encountered in the Space
Shuttle Main Engine prog."am have illustrated tile nee(i for extreme caution
in designing an(l fal)rieating systems for high pressure high flow oxygen
systems. The selection and processing'of structural materials are critical
factors in component (levelol)ment. The fnilures encountered have been
resolved nnd appropriate cimnges mn(le to ensure safe operation with respect
to the use of high pressvre oxygen.
IN'rROI)UCTION
Throughout the (levelopment nn(l testing" of rocket engines an(1 related
hardware, n variety of component failures has linen _ttribute(l to reactions
of materials with li(lui(ior gaseous oxyg'en.
"the Marshall Space Flight Center. l)cenuse of its role in rocket engine
development, has been n pioneering organization in research on liquid and
gaseous oxygen eomt)atibility with materials. The researeh dates back to
the predecessor organization, the Army l]allistie Missile Agency, during the
early 1950's development of the Re(lstone and ,lupiter missiles, and subse-
quently the lnrge Saturn rockets ti_at wero u.se(t in the Apollo program.
The Space Shuttle Main Engine (tevelot)ment program has ha(t the bene-
fit of past experienee in designing for hi_'h pressure lox/gox applications:
yet, for several l,'ensons, failures have l)eell (.'ncountere(l (lurin_ the develop-
ment phase of the pr(,?,'r:_m. Test fncility pr,oble, ms hnve bee, n eneotlnlered
because of the use of existing test e(luipment not spo, cific,_lly (lesituled for
the higher presst_res of the SSMF,. Some c,mq_on(,nl fnilur()s have cx_curred
becau.qe of extrem()lv hif_'h fl()wr:}tos of ()xvff,,n throtlg|l (lll(:ts and wdves
which were not fully optimize(I lo r(,(llu'_, t'h_w in(Itlce(I vihrntions.
This rep()rt (le,_erihes in narrnliv(, form the st_(.,'ifi(." fnilures encountered,
and discusses sorne of the e()rrec',tive gl_,liolls l:lken 1() l_revenl or r()(t,]c.e the
potential of |'tllur(" l'alilures.
|"AII,URI{ tll STOI_Y.
The following ehronolog-y lists the sig'nifieant failures that have
occurred :
1) March 1975- Santa Susana Coca4 Facility Valve
2) February 1976- Santa Susana Coca 1A Facility Valve
3) r,lareh 1977- Engine 0003, High Pressure Oxidizer Turbopump
Primary Seal
4) June 1977- Santa SusanaCoca 1B F,leility Valve
5) September 1977 - Engine 0004, llig'hPressure Oxidizer Turbo-
pump Instrumentation
6) April 1978 - Engine 0002. Injector l,ox Posts
7) June 1978 - Engine 0005, Injector I.ox Posts
8)
July 1978 - Engine 0101. High Pressure Oxidizer Pump
9)
September 1978 - Engine 0005. l,ox High Pressure Duct l:lowgxlide
I0) December 1978 - Engine 0007, lteat Exchanger
II) December t978 - Engine 2001, Main Oxidizer Valve
12) February 1979 - Engine 0201, Main Oxidizer Valve Seal.
FAI I,URE DESCRIPTIONS
March 1975 - Santa Susana Coca 4B Facility Valve
On March 7, 1975. an SSME Powerhead test (014) was underway at the
Rocketdyne Santa Susana Test Facility in l,os Angeles. California. when tile
test was terminated by an explosion. The test ol_i('etivewas to complete '_
preburner ignition and main combustion chaml,er iLnlition. The failure
resulted in moderate to extensive dam,_ffe to s(,x'cr:d('om;,t_nent_ of the
assembly. Most of the damage resulted from n combtlstion wave propagating
through the system from the ignition of mixed ffas(,_.t the nozzle ,,xit.
Figure 1 is a simplified schematic of the tost n_s,_,;l,]v, ltowevor, tho pro-
pellant feed lines contained numerous b'dl valvo_ . ;liters, and flowmaters,
as shown in Fig'ure 2. which is an isometric scl.,m:,tic of the e;×i(lizer system.
Note the flow of Iox from tho fox tank to tho nx-i,iiz(,r prei)tlrI_er (OPB).
LB-7 is a 2 in. 7t_00 series Annin valvo tlso.(I _i_ :t lox l)1(_o( ' valve, nnd is
located on a stub line to tile main flow line.
A schematic of this valv,, and
associated components and materials is shown in l.'ig't_re 3. This particular
valve was found to have a t)tlrned bonnet seal (Teflon). There vms no evi-
dence of significant prior contamination. Note that the wdve was installed
such that lox/gox pressure was over the ball. The downstream valves were
reversed, with the low pressure under the bali; thus. protecting the stem
paekingand seals from exposure to fox while in the closed position.
It was concluded that primary velocities nnd surges in the unprimed
stub bleed line. caused by m_dn line surg'es, could have resulted in pres-
sures of 20,000 psi and velocities of 400 ft/see. This would have resulted
in high temperatures, generated by atiiatmtic _ox compression in the stub
line. Temperatures on the ortter of 1220°F were calculated because of this
effect. The ignition temperatu,'e of Telqon at 30(}0 psi is approxinmtely
850°F. The Teflon seal was n static bonnet seal (Royce) of TFE Teflon with
an internal spring, used between the cop and betty of the valve. The spring
and seal were burned: no other damage (recurred to the valve. No other
cause, other than adiabatic compression, was found to explain the Teflon
ignition.
The explosion and major assembly damage were not attributed to the
Teflon ignition in the valve but to surges and overpressure in the system.
The Teflon ignition was caused by the pressure surge because of erratic
main lox valve opening, and the installation of the valve such that the Tef-
lon was exposed to the surge pressure.
Corrective action involved ehnnging the main wlve opening instrumen-
tation, serve systems instrumentation, redesig,nl of flowmeters to withstand
higher surge pressures, redesigm o|"filters, and reversal of several Annin
valves to protect seal areas from pressure surges while in the closed posi-
tion.
February 1976 Santa Susans C_a 1A Facility Valve
On Fehruary 4, 1976, _, verification lest of the SSME l,ow Pressure
Oxidizer Turhopumt_ (I,POTI'):_nd the High Pressure Oxidizer Turtmpump
(HPOTP) was t)ei,ag conducted qt the l{oekettlv_m Sant'J Susans Coen IA
Test Facility, when :l fire ,_curre(l :,1 nl)t)roximately 14 see into a programmed
mainstage duration of a 35 see test. Mm:h of lh_, total tiam_e to the test
hardware and the test stand resulted from _tlstadned burning of hy(lraulie
oil from a rut;tured manifold and llll,in_ stlpplyinL_ the contr(_l valves.
The I,POTP sustained minor internal damqffe. The IIPO'I'P was exten-
sively damaged throughout. Facility lines nnd v;dv(,s downstream of the
IIPOTP were ruptured nnd burned lhrou_h in s,,v,,r;_l areas. "i'h_,se parts
were damaged hv lox fires, but most of the test stand (lamgtt_'e was a result
of burning of lh_, spilled hydrmllie oil.