Post on 09-Sep-2020
TITLE:
I
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AUTHOR(H): Don O. Coffin
WEiMIITED?’C): Proccedlngs of 24th Conference on
Remote System Technology, 1976
By mreptunrv or tblm nrclclr for puhilcwflwt. ihrpubll~hvr rrco@zm the Ciovvmnwntms~llcenw) rlght~in unJ copyrlmhtund Ihv Govvrnmwtt and It* authorlmdr~tati- Imve unreetrlctd rlxht to rrprdm Inwhol~ or in ~rt neld artlds undm nny copyrlmhtorvurvd hy Lhv publhdwr.
Thv LowAhI- Hrlrnllflc Iaburatory rvqmlm that th~puhllAwr ideitIi@ this ttRlrlF ESwurk perfnrmwl undmthe auhpim of the UMHHI)A.
i/damesIe laboratory
of tho Univw9ity of Galifornla
An Allirmativa Ac?ion/Equol Oppertunilv Employeei“.
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High-Premmre Tri:iun
Don O. Coffin
Los Alanos Scientific Laboratory, University of California
P. O. Box 1663, Mail Stop 980, Los Almos, Sex Mexico 87545
11 pagen
4 figures
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High-Pressure Tritium
non o, coffinLos Alamoe Scientific Mborntory, University of California
Los Alamos, New Mexico
Abmtract
Some solutions to problems of compressing and cuntainin~ trltlum
gas to 200 MPa at 700 K are discussed. The principal eaphasis i~ on
commercial compressors and high-pressure equipment thn~ can be ameily
modified by the researcher for a=fe use with tritium, Experfmicc with
metal bellows and diaphragm compreasora has been favwablc. Selcctlon
of materials, fittings, and gauges for high-prmmmrc tritlum wrk is
also reviewed briefly.
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nnd infrequent maintenance is the mo~t important factor in reducing
personnel exposures.
GAUGES
Gauging In a particularly demanding problca becau~e tritium la a
controlled radioactive wterial, and its accountability at high prescurc
i- best done by accurate pressure-volume-temperature mtmsurements. Gfmgcs
that operate by deflection of an elarntlc wmber necessarily Incorporate
●mallcr safety factors than duslrccl for conservati~’e design. tlcverthe-
lea~9Bourdon-tube gauaes huvc served the prewure indu~try for inure than
a ccnLury. and nre u good cholcc for tritjum if th~ Bourdon material im
hydrooan-compat ible. ?fany ~nufacturer~ furnitih Eburdon guu~es in
austcnitic Otainlcsn mtccl~ or Iwrylllum cupper fn a wldc rangu of
pressurc~. The nddiclon of fnrcr-balancing nnd digltal””rrxlwt tech-
niques hJB greutly cnhmcml the preclnlon of tlwse inherently Rlmple
dcviccs. Strain-gauge transdu~ern are preferred by many cxpcrlmcntcrn
now. Solld-titatc dlgltal elcctronic~ and improvec quall~y control hnvo
resulted in prccisluns rivaling tho~e of the force-balm IJourdon-tube
systca$. A1l-uel.dcd trunsducors of trlttum-coiopnt lblc rn~crinl~ nr(q
n190 avnilablc from sev~~ral manufacturers.
COMPRESSORS
The principal cons~ralnts on trltlum pumps. cnumurutcd hy Fulkcr~
and Cedco4 ar~” that they Incorporutc no movln~ ~haft I+cal~, clnHLowr,!,
or orgnnlr fluldn. Comprcwl)r~ which cnn rcndily inwt thwc rl’quirc~nt~
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Classification (c) compri~c~ conpremms which c-ploy metal bellows
o: diaphragms, Several wnufticturrrs ❑aku dlnphragm cmprunsors6Bo~g
and ~hc brst m.udels in: tritium iucorpor~tc a ~tainlcsn ~tccl dlaphrag-
welded to the gas head. Since rc11a510 WOICIS arc dlf[lcult to mnke for
service above 100 ?lW, we are usin~ ~1 hydraulically londcd Meal of gold
plating on the gas diaphragm At 1~~ Wa no trltlum Irnkngc cm be
detected vit!l the usual portable air zonitor, and diaphra~m life in
mlmost iniinite if tho gas ig free of parttculntus. The utilization of
triple diapl~raym S (isg= 3) with mI appropria~c vunt port can slvc cffcc-
tivu secondary containment for thr nu;t llkcly mdc of compressor faflurc.
At this Laboratory we have urmd a mul:istn~c dhphrarp pump routinely
to coaprc~s tritfu2 to 1.’IOWa. The only continuing wlntunnncc has lmcn
frequ~nt (’han~~s of lntC!r!lt~~L! chc~”k ‘;IIvc’s, whlrh originally had flul)ro-
carbon fact! seals and cI~stornt’r poppnrs. These mntoriuls havv now hem
repla~.~’d with i101:;i2idU$J, nnd some of Lhctw vJlvcM urr still opcrntin~
●.211 ~fter Cw:j v,,.,r.+ .s[ IntcrmiLtcnt trlLiUM Murvi~c.
!4etal-bcllnxs conprcswr~ 10 h=~~ ~om,s on thu market in the past f-
year~, A design lini:atlon of the stfindilrd comprcswor for Lritlum IR
exceti~ivc usu ~f fluorrwarbon Plilstlc in the check-valve hmdcr. We
have rcpla:ed this with an all-metal valve nmembly, and r~.c manufacturct
will provide un ali-welded assembly at conisidernhlc extra co~t, Because
tha mechanically driven helluwn i~ unsupported, the output preRnurc iti
limltcd to about 0.5 WV. The only intcrc~t in thin pump for the high-
prcs~uru cxpcrinaentcr, tlmre[orc, 13 as a tran~fcr pump or first ●tago
of a multistdgc HyHtcrn.
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At thi~ Laboratory a balanced-pressure, hydraulically driven, metal-
belloxq coaprus%or has been built (Fig. 4). lt is designed to give a
50/1 cumprusslon aatiu nt 2C0 UPa diuchargc. Coupled to a suitable out-
put volum, it can provide very sensitive
hydraulic proportioning pump; driven by a
pump, it is capwble of onc 25&cm3 stroke
C~CLCSI~
presaurc control by uae of a
conventional hydraulic plunger
pcr minute,
Although several manufacturers make compresaora and hardware that
can bo modified for tritium uac. no current it-m of off-the-shelf equip-
ment la completely aatiafactory. For example, every diaphragm-pump supplier
UIJQS mm fluorocarbon or elastomer
COU~d be avnidcd. Tritlum usQrH in
infor~i industry on the requirements
tritiwn Is merging as a vital fuel
in the compressor even though these
the fusion-energy program must fully
for tritium handling. Now that
for the world’s future energy needs,
wc can and must aprly the best current technology to ita safe handling
and containmmt,
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1. J. F, Lakncr, “PruposcJ Prcwwru vrHs._l c, IncLI~:, ..tt., ,” ~lwrc~n.,~.
Livermorc Laboratory Report UCID-16833 (1!?75),
2. E. I. du Pent de :umour~ & Cuupan} (Inc. ) Pl:,s: ics 1}.”p:.,
Wilmington, DE 19S98.
3. Fluid Conpon~::t~ Division, Ikltrul Corp., Gr:ulL & XI:!I Ave.,
Bcllwood, IL 60104.
4. C. L. Folkers and Y. P. Cede, Prnc. .?3ril Conf. !kaoLe !iyst,
Teclmol., 55 (1975).
5. F. J. Edeskuty, lnd. Eng. Chcm. 51, 69 (1959).
6. American Instrument Co., Silver Spring, MI 22910.
7. D. H. Carstcns, Proc. 23rd Couf. lkmd~u Syst. I=r<n:.;., 69 (1975).
8. Preesure Products Tndutitrius. 9Wl Louis lW., !:.,rnil~+:.”r, PA 1B974.
9. Autoclave Engineersp 2930 H, 22nd St., Erie, i’A 16;12.
10. Metal Ilel.lous Co., 1075 Providence Hlglrsay, ~kti:~n, Y! 02067.
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:
. .
‘- secondary
Piston
High PressureA/olve
\J/JD. O. Col?fln“tligh-Pr@M3ure Trltium”
Fig. 1
1- Gas out
Hydrauhcin
II
+
———.
—.-
—. ‘K/
D. 0. Coffia“lliEh-Presaura Tritlum”
Fig. 2
To . WeldDumpTank r rGas Head
LOil Head
(3)
&..
LHydraulic In
I[1--- Position
1Indicator
Il.O. Coffin“l[l~h-Pru~HtlrcTrltlum”
Fig. 4