PROPERTY OF THE
CHEMICAL SEATTLE PUBUC UBRAftf
* M f t t L L U B O I C A l
____________ ENGINEERING____________
E S TA B LISH ED 1902 S. D. K IR K PA TR IC K . Editor
SEPTEMBER, 1942
MAT ERI AL A N D MATERI EL
B a c k
in the dismal days of the depression, we
argued endlessly about w hether our troubles were caused by over-production or under-consum ption.
Today when some essential w ar industries are be
ing slowed down In’ inadequate supplies of raw m aterials, everyone is asking,— “ A re these real shortages, or are we suffering tem porarily from m aldistribution and imbalanced inventories?”
The answer, now ju s t as it was ten years ago, is th a t it is academic to argue over nom enclature.
W e face, as we did then, a definite situation. W e m ust make im m ediately the necessary corrections and adjustm ents so th a t we can get going again at the highest overall ra te for the things we need most. T hat th a t means maximum production of w ar goods and absolute m inimum of everything else, now goes w ithout saying.
W e know th a t we have not m ade the best use of our m aterial resources in the past two years, b u t we have b u ilt a trem endous w ar in d u stry in much shorter tim e th a n any other nation in the world. Time has been of the essence and we have had to fight fo r everything we needed to do the job assigned to us. The p rio rity system itself en
couraged com petitive acquisitions. There have been too m any top ra tin g s fo r too little supply, p a rtic u la rly for steel and other critical construction m ate
rials. Is it any wonder th a t some inventories are badly unbalanced, th a t often substantial quantities of m aterials are tied up fo r w ant of one or two p a rts or products? We have heard reports of a m illion-dollar w ar p ro ject held up fo r w ant of
$20,000 w orth of alloy steels. Meanwhile other plan ts to supply com plem entary m aterials m ust shut down or m ark tim e to keep from piling up
“ too much and too soon.”
Donald Nelson, who has lately had to fight off his critics w ith his back almost to the wall, had the only common-sense answer. “ The big job ahead of us rig h t now, ’ ’ he said on A ugust 22nd,
“ is to b rin g our program into balance and to make sure we use our m aterials and our facilities as
wisely as possible.” W hether such good advice is going to be followed voluntarily by in d u stry is an open question. A workable system of inventory control through complete allocation of production requirem ents m ight be the answer. B u t when it comes to requisitioning an d re d istrib u tin g goods already in p rivate hands, something more than general directives from W ashington will be needed.
Definite policies m ust be established and enforced by the government. H ere is a job th a t calls for stronger, more direct action th an any we have yet had from this adm inistration.
One blind spot in m any of our calculations is the large percentages of the o u tp u t of certain raw m aterials th a t have been and are still going out of the country. This is p a r t of a gran d strategy, which ap p a ren tly has the approval of the m ilitary authorities. Yet in cases where critical w ar p ro duction in this country is held up for w ant of m aterials being exported u n d er Lease-Lend, it is obvious th a t we are no t following th a t “ w isest”
course in utilizing our own great resources.
In our concern with the immediate situation, which we hope is already in the process of being corrected, let us n o t lose sight of the fa ct th a t we are in a period of tran sitio n to a different and more ab u n d a n t m aterials economy. W e are op
erating m any basic industries a t higher levels th an ever before in history. W e are ju st beginning to realize some of the advantages as well as lim ita
tions of a g reatly expanded volume of business.
F o r the first time we are seeing w hat our science and ' technology can do when the production en
gineer is given the rig h t of way w ith the th ro ttle wide open !
So, as we push ahead to produce the trem endous supplies of m ateriel required for our w ar effort, we m ay take some b yproduct credit for helping to build a b e tte r post-w ar economy. In th a t proc
ess of m eeting to d a y ’s problem s and p re p arin g for
tom orrow ’s, we hope th a t this T enth M aterials of
Construction issue of Chem. & Met. w ill serve as a
useful and practical source of reference—both for inform ation and inspiration. I t tells m any stories of m aterial and m ateriel of whieli the chemical engineering profession may well be proud.
LIFE BEGINS
Fo r t y
years is not very long in the history of A m er
ican industry. Y et since Vol. 1 No. 1 of this m aga
zine appeared as Electrochemical In d u stry in Sep
tem ber 1902, its field lias undergone significant changes. F ir s t there was the bu d d in g in d u stry th a t sprang up around N iagara F alls as cheaper hydro-electric power first became available. Elec
trom etallurgy followed closely on the heels of elec
trochem istry arid in 1905 the field of the magazine was extended in th a t direction.
“ E n g in eerin g ” first became a p a r t of our name in J a n u a ry 1910 because, said the editor, “ we wish to emphasize th a t this jo u rn al is not, on the one hand, a trad e paper, n o r on the other han d a periodical representative of p u re science. R ather, we are concerned w ith . . . w hat is needful in the work of the engineer in the conduct and m anage
m ent of . . . chemical w orks.”
I t is interesting to note th a t the same editorial forecast the unit-operation concept of chemical engineering when it rem arked th a t all those “ en
gaged in engineering practice in in d u strial estab
lishm ents are more or less interested in the same processes—in crushing an d grinding, concentration and separation, d ry in g and evaporation . . . e tc .”
Chemical engineering arose to meet the challenge of the first W orld W a r and th a t ascendancy was d uly noted J u ly 1, 1918, when, “ Met. & Cliem.”
became “ Chem. & M et.” T h at was almost a q u a r
ter of a cen tu ry ago. Today all of us are again
faced w ith new problem s and responsibilities. We on Chem. tf: Met. consider ourselves fo rtu n a te to be allied with a resourceful in d u stry and profession th a t offers so m any opportunities fo r serving our country in its present need. We are encouraged to believe w ith Professor P itk in th a t “ L ife Begins at F o rty .”
GET IN THE SCRAP!
Wa l t e r Ca r p e n t e r,
able p resident of the du P ont company, is helping the A m erican In d u stries S al
vage Committee to ca rry its program into every company in the chemical industry. He has urged his fellow executives to get behind the work of the Ind u strial Salvage Section of W .P.B . “ This is a situ a tio n ,” he said, “ w herein b y helping our Gov
ernm ent, we are also helping ourselves; because in d u stry cannot do a satisfactory job of production w ithout more scrap m aterials th an are norm ally available. . . There is needed an ex trao rd in ary cleanup of our factories, involving recognition of the fact th a t if a m achine or pipeline, a heating plant, a building . . . is not absolutely essential for production at this time, th en consideration should be given to scrapping it. I f we d o n ’t win this war, most of our factories will be scrapped any- way
! ”In 1,200 different communities, W .P.B . has set up general salvage committees. In 400 in d u strial centers there are representatives of its In d u strial Salvage Section ready to help in organizing effect
ive salvage work in factories, offices and labora
tories. This assistance is yours for the asking.
W rite or wire the Conservation Division, W ar P ro duction Board, R ailroad R etirem ent B uilding, in W ashington.
W a s h i n g t o n H i g h l i g h t s
P R IO R IT Y
policies now pinch severely on research and control laboratories which use as much as $5,000 per quarter o f scarce m etals. This makes the laboratory director responsible fo r P .R .P . quarterly filings and the pursuance o f the rest o f the P refer
ence R ating ritual. Obvious rem edy is to adapt old facilities to new pur
poses in the lab as w ell as in the works, whenever this is possible, even with the sacrifice o f a bit on effi
ciency.
C O N C E N T R A T IO N
o f production in a few plants is to be extensively prac
ticed in m etal-w orking industries.
There m ay be a few cases w here this practice can be h elp fu lly applied in the chemical industries. I f a single producer has fa cilities to m anufac
ture all the needed quantity o f som e chemical, there ought to be means by which anti-m onopoly rules can be
suspended to perm it that efficient plan o f operation, i f it is really o f benefit in savin g skilled m anpower.
B u t long transportation and con
fusion in su p p ly for essential users must not creep in as a secondary e f fect or the benefits o f concentration o f production w ill be overshadowed and the w ar program hurt rather than helped. P robably on ly a few chemical cases w ill really q u a lify for this program .
G U A R A N T E E S
o f both quality and price for dom estic soap su p p lies is undertaken in recent actions o f O .P.A . One wonders how the quality o f certain detergents can be guaran
teed when alm ost essential raw m a
terials like coconut oil are obviously not available. M aybe O .P.A . w ill p ro
vide som e new laboratory technics to help the much bufTetted soap ex
perts. W e wonder.
R E C O R D P R O D U C T IO N
o f synthetic organic chem icals in 1941 is reported by the prelim inary statistics o f U. S.
T ariff’ Commission, issued in mid- A ugust. This division o f the chem
icals industry sold $724,000,000 worth o f goods last year. This w as an increase o f 50 percent over the previ
ous year’s sales which had been the highest on record. The rate o f growth and the adequacy o f synthetic chem
icals su p p ly probably surprises no one, except, we believe, our A x is con
tem poraries.
N E W C O S M E T IC S
are virtually prohib
ited by the regulations restricting containers and the use o f container m aterials. Comparable p olicy is su g
gested by W .P .B . actions on more im portant industrial m aterials. B ut fortu n ately there is no tendency to discourage new chem icals which have a real w ar-tim e service value.
84— Í) S E P T E M B E R 191,2 . C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G
c t t E M & A í e r
t f t o
° * r
0 *
M aterials for the Construction of Chemical E n g in e e r in g Equipment
The war is having a tremendous effect on all materials, in particular aluminum, stainless steels, nickel, copper, rubber, and others which the chemical engineer has become accustomed to specify for construc
tion of his equipment. The source of natural rubber is in the hands of the enemy, stainless steels are in demand for ships, guns, and tanks;
copper for shells; aluminum for airplanes; rubber for jeep tires and a
thousand other uses. The process industries must share the supplies of
these strategic materials. It is essential that the limited amounts be
conserved and made to stretch as far as possible, that life of present
equipment be prolonged throughout the period of the emergency, and
that substitutes be used whenever practical. For the success of the
Victory Program depends in no small measure on their availability for
the construction of equipment so badly needed to swell the supplies of
synthetic rubber, 100-octane gasoline, and chemical warfare agents
for the armed forces. Chem. & Met.'s Tenth Materials of Construction
Issue should serve a timely and useful purpose. It presents the ways
and means for conserving and protecting materials and equipment. Its
data sheets bring up to date the basic information on manufacturers,
composition, and corrosion, heat and abrasion resistance. In effect, it
is a complete mobilization of available information.
M a te r ia ls o f C on stru ction for T o d a y a n d T om orrow
S U M M A R Y A N D
Realizing the seriousness of the present situation in materials for corrosion, heat and abrasion re
sistance, the editors in this report have suggested means by which engineers can get most out of what they now have. For the benefit of those who can not obtain the materials they would normally specify, the availability of substitutes or alternates is discussed. The world upheaval is necessarily having a tremendous influence on the entire field of materials and has called for a look at the mate
rials of tomorrow.
Properties of metals and alloys are presented for the first time on a series of fold-out inserts for
C O N C L U S I O N S
simplicity in handling. For each material are given the manufacturer's name and address, the composition, and resistance to abrasion, to heat, and to commonly encountered chemicals. The trend towards adoption of standard uniform no
menclature for all alloys has been given further inpetus by development of a system of designa
tions for heat and corrosion resisting castings by the Alloy Castings Institute. The influence of the war is reflected in the tabulations of information on non-metallic materials. A vast new synthetic rubber industry is in the making and new plastics are available to the engineer for the first time.
C o n se r v a tio n o f M a te r ia ls
t t r r i H E CIVILIAN ECONOMY is fa st JL goin g on a minimum subsist
ence standard, vital m aterials no longer can be used excep t fo r war, and fo r the m aintenance o f tliose things necessary to carry
011the war.
The past months have been relatively easy, the m ilitary has taken from the civilian to meet its needs. This pool is nearly dry, from here on out it w ill be a continuous problem to meet the needs o f our fighting forces. Industry must get ready to ‘Patch and P r a y ’ to keep existin g equipm ent at work,”
w arns W . L. B att, chairman o f the R equirem ents Committee o f W P B . J u st as long as the em ergency exist?
the m etals and their alloys, with the exception o f lead, which the chemical engineer lias become accustomed to depend upon fo r the construction o f his process equipm ent w ill be difficult to obtain unless lie is fortunate enough to possess a high priority.
This situation is not lim ited to the m etallic m aterials, fo r rubber is in the sam e category. A nd w hile there are not the same restrictions
011chem
ical stoneware, glass, wood, and the other non-m etallic m aterials, never
theless, the heavy demand m akes de
livery o f new equipm ent slower than it is in normal times.
A s Mr. B att warned, the engineer m ust be resourceful in conserving the
su p p lies o f strategic m aterials and in prolonging the life o f present equip
ment. W hen new equipm ent is planned much can be done to stretch the su p p ly o f strategic m etals. In some instances this m ay be accom
plished by sp ecify in g lin in gs over a base metal. Probably the greatest con
servation can be obtained by more careful study o f each item, and use o f the low est possible alloys which are now in commercial production, as V . W . W hitm er recently stated before the A .S.T .M . F or exam ple, there are undoubtedly m any applications using chromium-nickel alloys w here the straight chromium could be very easily substituted.
Favorable design should be con
sidered which w ill provide against the presence o f crevices, pockets, or other areas that m ight prom ote accu
m ulation o f deposits or stagnant liquors. In cases where excessive cor
rosion a t one or more points in a vessel has been troublesom e it is well to exam ine carefully fo r the presence o f those areas which m ight be re
sponsible fo r this su sceptibility to corrosion.
E xcessive wear in vessels, pum ps and p ip in g frequently is due to inade
quacies o f design. R eduction in rates o f flow, or slig h t changes in direction o f flow, m ight be sufficient to reduce
excessive w earing o f p ip in g and valves. E xcessive wear o f pum p parts m ight be due to use o f im proper al
loys fo r w earing m em bers; as "well as to im proper or inadequate lubrica
tion.
The design and location o f vapor connections should be such as to pro
vide against refluxed condensate run
ning down the w alls o f the vessel instead o f drop p in g fr e e ly into the liquid. Im provem ents frequently re
sult through changing the location o f critical parts to points outside the condensation zone, or by process changes which lim it the region in which condensation is occurring, as fo r exam ple by reduction in process tem perature, jack etin g the vessel, or sim ilar operation readjustm ents.
U se o f the sam e typ e o f m etals to
gether where possible is recommended in order to avoid galvan ic corrosion.
I
11the cases where necessity demands that dissim ilar m etals and alloys be used together in corrosive environ
ments there are certain definite rules to follow' in order to assure success o f the com bination. W hen dissim ilar ma
terials are to be used together it is best to determ ine beforehand that both have adequate resistance to cor
rosion by the process liquors under normal conditions. N ickel, Monel and the other high-nickel alloys m ay nor
m ally be used together with safety, and with copper, bronze, brass and
80— 9 S E P T E M B E R 19-',2 • C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G
other copper-base alloys. In combina
tions w ith p lain and low -alloy steels and cast irons, and with aluminum, zinc, and other m etals less noble than nickel opportunities fo r appreciable galvanic corrosion m ay exist, and the proposed metal com binations should be considered carefully before new installations or changes in existing equipm ent are made.
Com binations o f the relatively noble nickel and high-nickel alloys w ith less noble m aterials, such as steel and cast iron, are usually satisfactory when the exposed area o f more noble m aterial is sm all in com parison with that o f the less noble.
W hen it is im possible to avoid using galvanic couples suspected as being dangerous non-m etallic insula
tion in the form o f gaskets, sleeves, and washers are recommended. These insulating gaskets should be applied in a manner to provide com plete elec
trical insulation between the m ate
rials form ing the couple.
I t is good practice whenever fe a sible to coat large surfaces o f the more noble m etal in a galvanic couple w ith an in su latin g paint so as to re
duce the effective area o f the cathode in the galvanic cell. The use o f ca- thodic protection, either from applied current or by sacrificial corrosion o f a less noble m etal such as zinc, may serve to lessen galvanic corrosion w hich otherw ise m ight occur. In some instances where galvanic corrosion is not a problem the application o f a protective current m ay serve to pro
lon g equipm ent life or reduce m etal
lic contam ination w here such is an im portant factor.
" A N O U N C E O F P R E V E N T IO N "
M any m eans m ay be used fo r ex
tending the life o f equipm ent already in service. P eriodic and careful clean
in g o f equipm ent is a m ost im portant factor in assuring greatest possible life. B e sure to use cleaning agent recommended fo r the surface m ate
rial. In the case o f w ire mesh and other process equipm ent utilizing m etal in sm all sections it is o f the ut
most im portance that acid cleaning agents be thoroughly flushed and rinsed off after the desired cleaning has been accom plished. This is im portant because the presence o f di
luted acid in restricted areas, aw ay from free flow o f process liquors, m ight prom ote concentration cell cor
rosion. This same precaution is neces
sary in large vessels especially around seam s and connections where the typ e o f jo in t is lik ely to be such as to pro
vide a crevice.
Other precautions that w ill
lengthen the life o f equipm ent should be mentioned. B e sure that the metal is recommended fo r use in the pro
duction and handling o f the particu
lar chemical or combination o f chemi
cals. Inhibitors are w idely used to prevent attack by hydrochloric acid and other chemicals, but several authorities contend that even greater use could be made o f these interesting agents.
S T A IN L E SS STEELS
The service life o f stainless steel equipm ent can be lengthened by fo l
low ing certain precautions. Remove m aterials and deposits that tend to adhere to the surface, especially in crevices and corners. C leanliness can not be stressed too strongly. W ork fo r uniform ity in regard to solutions, tem peratures, agitation, concentration and surface conditions. A void pro
longed standing o f chlorides, bro
mides, thiocyanates and iodides in stain less steel equipm ent, especially if acid condition exists. The p ittin g ac
tion o f these compounds m ay be re
tarded or avoided by m aking solutions alkaline. I f this is not possible, avoid long contact o f com pounds with the metal and clean frequently. B e sure to avoid corrosion fa tig u e. This is usually the result o f a com bination o f cyclic stresses and w eld corrodents.
The remedy is to make the equipm ent sufficiently strong to w ithstand any stresses which m ay be encountered. I f this is not possible, the equipm ent or unit should be so constructed as to permit freedom o f movem ent o f the entire unit.
N ICK EL
In the case o f nickel and the fam ily o f high-nickel alloys, cleaning m ay be done w ith any o f the alkaline clean
ers. D ilute acid cleaners, such as s u l
phuric and hydrochloric, are also used extensively, and when so em ployed in correct strengths and at warm tem
peratures are not detrim ental to the life o f the materials. W ith some ex
ceptions, nickel, M onel, and other nickel alloys which do not contain substantial amounts o f chromium should never be cleaned with nitric or other oxidizing acids since these are corrosive to nickel and the other al
loys m entioned, and w ill cause loss o f metal through corrosion.
Scouring o f nickel and nickel alloys is best accomplished w ith abrasive cleaners, such as finely divided pum ice, or w ith those preparations com
pounded fo r household use. Steel wool or steel w ire brushes should never be used on nickel and nickel alloy equip
ment since their use presupposes the likelihood that fine particles o f steel w ill become embedded in the metallic surfaces with later developm ent o f rusting, and occasionally localized attack under the rust deposits. I f brushes are to be used w ith the abra
sive cleansers a stiff typ e o f fiber brush is the best choice. M etallic wool scouring pads o f nickel and M onel are com m ercially available and should be used where more severe scrubbing or scouring is indicated.
The use o f organic inhibitors, o f the typ es added to steel pickling acid solutions, w ith the cleaning acids em
ployed on nickel alloy equipm ent is recommendsd.
The use o f im proper w elding or brazing rods in m aking repairs on nickel and nickel alloy equipm ent frequently leads to trouble since the weld metal being o f different com posi
tion from that o f the parent metal m ay i f less noble suffer accelerated galvanic corrosion. F abrication and repairs are o f course best made with rods o f com position identical with that o f the m aterial being joined.
LEAD
Lead’s resistance to corrosion de
pends in part on the extent to which its protective surface layer can be kept continuous and unbroken. B y designing equipm ent in such a w ay as to restrict unnecessary m ovem ents o f the m etal or by exercising reason
able care to prevent m echanical in jury to the protective coating lead w ill often last for a long time.
R egarding installation, the im por
tant poin t to remember is that lead requires adequate sup p ort at all
L ite of s t a i n l e s s s t e e l m a y b e l e n g t h e n e d b y r e m o v a l of a d h e r i n g m a t e r i a l s
C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G • S E P T E M B E R 19/,2 •
points where stresses m ay occur.
Proper support not only reduces the p ossibility o f mechanical fa ilu re but also restricts movem ents o f the m etal which, as pointed out above, are a contributing factor in corrosion.
Lead p ip es in the horizontal p o si
tion are usually supported by placing them in steel or wooden troughs. V er
tical p ip e lines m ay be held in p o si
tion -with steel strap s, spaced 18 in.
or so ap art and securely bolted to a rigid su p p ortin g structure. Another method o f su p p ortin g lead pipe, either vertically or horizontally, is by inserting and expanding it in stand
ard steel p ip e. U sers o f this proce
dure report that it is not only more satisfactory but cheaper than angle iron or w ooden supports.
A s in the handling and installation o f lead, so in the treatm ent o f lead equipm ent in service avoidance o f physical injury and a proper regard fo r the m etal’s mechanical lim itations arc the gu id in g principles.
F or exam ple, w hen d epositing or rem oving objects from a tank, care should be taken to avoid unnecessary contacts with the lin in g which m ight nick the lead or abrade its protective coating. A gain , chemical solutions o ften deposit crystals, scales, crusts and the like, the removal o f which is o, common source o f injury to linings.
W orkmen entering the tank should wear rubbers or other shoo coverings.
Shovels, hoes, rakes and sim ilar tools should be used with an appreciation o f the necessity fo r careful handling to avoid trouble.
W here heating coils are em ployed, turning on o f the steam should be done gradually through the use o f needle valves. A sudden surge o f pressure m ay distort the coils, rupturing the protective coating as w ell as w eaken
in g the m etal structurally. The in stallation o f therm ostatic or pressure controllers which guard against ex
cessive pressures and tem peratures frequently prevents damage to coils through carelessness. The use o f hot w ater instead o f steam as the heating medium is another method o f pro
lo n g in g coil life , particularly where m oderate tem peratures are em ployed with chem icals such as chromic acid.
W hile the form er takes longer to raise the solution to the desired tem pera
ture, corrosion o f the coil itself is retarded.
A LU M IN U M
F or most applications there is little or no reaction between aluminum and the substances being processed. In other cases, som e reaction m ay occur.
In cases o f this ty p e, it is often p os
sible to extend the life o f equipm ent appreciably by suitable protective m easures (H . J . F ahrney and R. B.
H ears, Chem. & Met., V oi. 49, pp . 86- 89, J u ly, 1942).
Several protective measures which have proved beneficial are available.
These m ethods include: (1 ) cathodic protection, (2 ) coatings, (3 ) chemi
cal inhibitors, and (4 ) periodic cleaning.
Each o f these m ethods has special fields o f usefulness. Cathodic protec
tion is particularly suitable fo r pre
ven tin g attack by unrecirculated w aters and by nearly neutral or sligh tly acid salt solutions. The liquids m ust have a relatively high conductiv
ity and only areas o f the metal ex
posed in contact with the liquid can be cathodically protected. In cases where it is applicable, cathodic p ro tection is u su ally the cheapest and m ost effective method o f preventing attack.
Chemical inhibitors are particu
larly u seful in recirculated w aters or in cases where the same m aterial is to be stored for relatively long periods o f time in the equipm ent under con
sideration. A s with cathodic protec
tion, on ly the metal areas below the liquid level are norm ally protected by inhibitors.
P rotection against more severe con
ditions, such as the stronger acids, can best be obtained by coatings.
These can be ap p lied most readily to new equipm ent or to units which can be easily handled.
P eriodic cleaning has proved most useful in cases w here solid products settle out on the m etal surface and adhere tenaciously to it. It is gener
a lly o f little use where the liquids being processed uniform ly dissolve the metal surfaces which they contact.
RUBBER
IIow to conserve rubber equipm ent w as discussed in a recent article ( 0 . S. True, Chem. <0 Met., V o l. 49, pp. 8 8 -8 9 , M ar., 19 4 2 ). In the p lan ning w hich precedes the actual in stallation o f rubber-lined equipm ent, the engineer should be careful to give the rubber m anufacturer fu ll and ac
curate inform ation concerning service conditions. Specifications differ a p preciably and the life o f any in stalla
tion m ay depend g reatly on the com pleteness o f the original inform a
tion.
In the case o f rubber-lined equip
ment, i f it is necessary to enter, w ork
men should w ear rubber-soled shoes to avoid abrading and cutting the lin ing. Care should be taken against the p ossib ility o f w elding sparks or tools
dropping into the tank from construc
tion overhead. I f there is a p ossib ility o f mechanical damage to the lining, it should be protected by wood bumper strips or brick lin in gs set with acid-proof cement. H ard rubber- lined equipm ent should be protected against external shock— particularly in cold weather.
In the case o f solid hard rubber material, operators should be in
structed that the m aterial is brittle and that normal m ethods o f p ip e han
dling should n ot be used. P ip e lengths should lie fu lly supported, strap wrenches should be used fo r draw ing threaded ends together, and tem pera
tures and pressures should be w ithin a range suggested by the m anufac
turer. Such p ip e should be k ep t aw ay from points where there is an excess o f traffic and especially aw ay from hand trucks, etc.
C A R B O N A N D G R A P H IT E
Carbon and graphite p ip in g must be handled w ith a minimum use o f high-prèssure tools. It is recom
mended that p ip e be handled and tightened by hand or w ith assistance o f a rope wrench.
I t is a good idea to carry in stock repair couplings and slab m aterial.
I f a break does occur the broken pieces can be collected, fitted into original position and cemented to
gether using carbonaceous cements recommended for the particular pur
pose by the carbon m anufacturers.
Should the broken pieces be too small to ju s tify this typ e o f repair it can be made by u sin g the slab stock in store. Carbon slabs can easily be shaped to proper dim ensions and ce
mented over the op en in g in the vessel.
G L A S S L IN IN G S
G lass-lined equipm ent that receives reasonable care is long-lived. There are m any installations in good work
in g order that have had continued use fo r over 20 years. The m anufacturers report that i f the fo llo w in g instruc
tions are follow ed the life o f lin in gs can be lengthened m aterially:
1. W licn r e a d y t o c le a n , cool th e e q u ip m e n t b y flo o d in g t h e ja c k e t w it h cold w a t e r , th e n r in se th e in sid e w it h cold w a te r to r e m o v e d e p o s its fro m th e su r fa c e .
2. S cru b th e g la s s lin ed su r fa c e w it h d e te r g e n t so lu tio n . U s e a co m m e rcia l d e te r g e n t w h ic h c o n ta in s o n ly a fine a b r a siv e an d so a p . T a k e on e p a rt d e te r g e n t an d tw o or th r e e p a r ts w a te r , m ix a n d b oil. (W h e n b o ilin g w ith d ir e c t s te a m in s o lu tio n , u s e o n ly t w o p a r ts w a te r .) P e r m it s o lu tio n t o co o l, s tir r in g o c c a s io n a lly to k eep a b r a siv e p o w d e r in su s p e n sio n . S o lu tio n w ill fo r m je lly lik e m a s s w it h a b r a s iv e e v e n ly su sp en d ed .
8S— .9 • S E P T E M B E R W.}2 • C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G
3. D ip w e t b ru sh in to d e te r g e n t s o lu tio n a n d scru b eq u ip m e n t. D o n o t p u t d e te r g e n t s o lu tio n in tlie v a t.
4. A f te r e q u ip m e n t h a s b een scrubbed th o r o u g h ly , r in se W ith cold w a ter.
5. T h en rin se w it h h o t w a te r . 0. S te r iliz e a cco rd in g t o n o rm a l p r o ced u re, e ith e r b y h e a t in g th r o u g h th e ja c k e t or d ir e c tly w it h a s te a m h o se.
In c a se o f th e la t te r p roced u re, k eep th e end o f th e h o se a t le a s t 12 in.
from th e g la ss -lin e d su r fa c e . D o n o t u se h o se w it h m e ta l n o z z le or m e ta l w e ig h t on end o f h o se.
FU SE D S IL IC A A N D S T O N E W A R E
V itreous silica industrial equip
m ent gives little trouble, but there are a few precautions that i f follow ed w ill add length to its life. A void use o f rigid join ts between fused silica and other m aterials, all o f which have higher thermal expansion, i f the join t is to be subjected to high tem pera
tures. I t is advisable to avoid the use o f hard settin g cement on fused silica equipm ent at high tem peratures fo r the same reason.
This equipm ent is suitable for op erating tem peratures up to 1,000- 1,100 deg. C. in the absence o f certain mineral salts or reducing gases which m ay accelerate breakdown due to de
nitrification. Tem peratures as high as 1,350 deg. C. are possible if critical tem perature zones between 1,250 deg.
C. and 1,300 deg. C. and below 300 deg. C. are avoided.
F ailu re o f chemical stoneware equipm ent m ay usually be traced to the use o f the wrong body or to fa u lty installation. Stonew are bodies differ in their physical properties as w idely as do different grades o f steel and must lie selected w ith equal care with particular reference to the service ex
pected o f them. The equipm ent should be installed so as to allow fo r expan
sion and contraction, to minim ize vibration and tensile stress, and to take fu ll advantage o f the extrem ely high com pressive strength that is characteristic o f the ware.
SY N T H E T IC R E SIN
Tanks or other pieces o f phenolic resin equipm ent, damaged in transit or by accidents in operation in such a m anner as to produce holes or breaks m ay be refilled w ith some o f the same typ e o f resin and made as good as new w ithout excessive cost.
M inor repairs can be made on the prem ises by the user’s own men and the equipm ent can be placed in serv
ice again after on ly a few hours. Sur
fa ce damage need cause no concern as the material possesses uniform chemi
cal resistance throughout.
The foregoing attem pts to suggest a few o f the w ays by which the ex
trem ely lim ited stocks o f strategic m etals and alloys m ay be made to go farther and m eans fo r protecting w hat equipm ent we already have in an effort to make it last through the em ergency. E very success that is thus achieved helps in w inning the final V ictory.
A lte r n a te M a te r ia ls
M
o s t c o n s t r u c t i o n'm aterials
problem s,m et in the design o f equipm ent and buildings fo r chem
ical process industries are capable o f a number o f different solutions, and in normal tim es the engineer’s task is to discover those m aterials which come closest to the ideal. These, however, are not norm al tim es. M etals in par
ticular, as w ell as rubber and plastics, are becom ing increasingly difficult to secure, p a rtly on account o f actual shortages, and p artly because o f ex
cessive inventory stocking on the part o f som e m anufacturers. Certain o f the scarcest m aterials are already sub
ject to com plete allocation, and others are sure to be added to the list. A t p resent allocated m aterials can be had only fo r the most essential purposes and when nothing else, in the opinion o f the authorities, can be substituted.
B ut i f current W ar Production Board m oves are carried through, it is prob
able that such m aterials w ill not be available at all fo r production equip
ment, but on ly fo r the m anufacture o f offensive w eapons.
To an ever larger extent, therefore, chemical engineers are finding it nec
essary to use m aterials which are in
herently more p len tifu l, or in less demand, than the ones they m ay have been accustomed to use. Som etim es new m aterials can be found which w ill perform as satisfactorily as the old m aterials, or even better. In other cases, new uses are possible for old
materials, or new w ays o f using them can be discovered. In general, how
ever, the question o f alternates comes down very largely to the application o f w ell-known m aterials, which fo r reasons o f personal preference, higher costs, or certain not-so-satisfactorv properties, were ruled out before the preferred m aterials became unavail
able. I t is in the last group o f pos
sibilities that the great preponder
ance o f solutions w ill be found.
U nfortunately, m any o f the con
struction m aterials that are being ad
vanced as alternates are themselves hard to get today, ow ing to difficul
ties in transportation, or lack o f s u f
ficient production capacity to meet the present inflated demand. W ith m any, the demand is now so large that reasonably rapid delivery can be made o n ly to holders o f relatively high p riority ratings. Still, this state
m ent is true only in a number o f cases, and does not a p p ly to all ma
terials, nor to all equipm ent m anu
facturers. Each case m ust be checked individually. Furthermore, the su p p ly situation is in a constant state o f flux, and generalizations which are correct at one tim e m ay be untrue a week or a month later. A n exam ple is the ease o f lead, which a few m onths ago w as one o f the scarce m etals. A t present, lead is listed in the W ar Production Board’s Ma
terials Group I I I , which includes m a
terials available for substitution.
C apacity to produce, rather than the availability o f raw m aterials, is the lim iting factor with m ost alter
nate m aterials. A s a general rule, the best prospects for adequate su p p ly are found with those m aterials which require the least m anufacture, and make use o f the least metal.
W ood, cement and clay products are in this category, although even these m ay be scarce in some localities, w hile certain typ es such as structural lum
ber and refractory brick m ay be d if
ficult to obtain anywhere.
C onversely, m anufacturing bottle
necks in the ease o f other m aterials which ordinarily are easy to obtain have become fa ir ly pronounced at present, and m ay become even more severe. Chemical stoneware, esp e
cially the more highly fabricated form s, requires m aterially increased delivery time. The same is true o f structural carbon and o f industrial glassw are. Several o f the plastics which would ordinarily be considered as available fo r alternate use are even harder to get than metals, including phenol-form aldehyde, acrylic and m ethacrylate, and vinyl chloride plas
tics, as w ell as synthetic rubbers and rubber reaction products. W ith the exception o f natural rubber, all o f these m aterials are o f dom estic origin, but com petition w ith other w ar prod-, ucts fo r necessary raw m aterials and interm ediates, and com petition for the finished plastics, has made them unavailable fo r all but exceptional uses.
C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G • S E P T E M B E R 1911 5— 89
T h e s e t h r e e b o ilin g t a n k s a r e b u i l t of K a r b a t e s t r u c t u r a l c a r b o n w h i c h is u s e d lo t w a l l s l a b s , h e a t e r t u b e s a n d h e a d s a n d t h e p i p e s , v a l v e s a n d iitti n g s
The higher alloy steels together w ith copper, nickel, aluminum, m ag
nesium and their alloys can, o f course, be obtained only on allocations. To save alloying elem ents in those steels which em phasize m echanical and physical properties, rather than tem perature or corrosion resistance, sev
eral new series o f lean alloy steels, known as the N E (N ational E m er
gen cy) steels have been developed by the steel industry and accepted by the W ar Production Board, and such steels must now be specified by metal fabricators fo r all uses where the need fo r higher alloys cannot be d ef
in itely established. E ven these steels, however, can be obtained only with W P B perm ission, for the su p p ly must be conserved fo r essential uses.
Tn the process industries, obviously, many construction m aterials are se
lected for their corrosion or heat re
sistance, rather than fo r m echanical properties, and so with alloys it is gen erally im possible to achieve the necessary resistance and still scale down the alloy content to any con
siderable extent. This situation is in part recognized in W P B Order M-21-g, which sets the maximum alloy content for a variety o f heat-resisting applications.
The situation regarding cast iron seems to vary considerably. Some foundries appear to have plenty o f m aterial and are able to give rapid service, w hereas others are demanding and gettin g high priorities for the work they perform , in any event, together w ith other m etal fabricators, the foundries which consume more than $5,000 worth o f metal per quarter m ust now subm it their de
tailed quarterly requirem ents fo r gov
ernment approval under the Produc
tion Requirements Plan. Presum ably, as this plan becomes more effective through application o f the experience now being gained with it, cast iron m ay become som ewhat less freely ob
tainable.
M ETA L S F O R M ETA LS
Although most m etals used fo r cor
rosion resistance, fo r alloyin g and for p la tin g are
011the critical list, there are several m etals which can still be secured fo r use as substitutes. A lso, o f course, there is alw ays the possibil
ity o f conserving the scarcer metals by using them as 10 or 20 percent plym etals. One interesting substitu
tion that has recently been proposed to replace tantalum is to use platinum plated on copper or brass tubes for applications in contact with hydro
chloric acid where good heat transfer must be secured. Gold is available for
such applications and may be em
ployed either as a plated coating or in the form o f a plym etal. Silver, orig
inally believed to be adequate in quan
tity fo r substitution, is now alm ost entirely under allocation.
A s has already been noted, lead is now quite p len tifu l, w hich applies also to certain o f its alloys used fo r equipm ent construction purposes, such as tellurium and antim onial lead.
A nother available m aterial is a new high strength lead alloy, designed particularly fo r w ater-service p iping.
N O N -M E T A L L IC A L T E R N A T E S
Carbon— A p p lication s o f struc
tural carbon have developed rapidly in recent years. A m ple raw material is available despite the enormous de
mand fo r carbon electrodes. The present chief deterrent to more w ide
spread use o f structural products lies in fa cilities fo r producing finished materials. Carbon can be obtained in both ordinary and im pervious form s, as w ell as in a porous variety fo r filtration and bubble-producing applications. It is being fabricated in a w ide variety o f standard brick and block shapes, the latter so large as m aterially to reduce construction tim e o f large equipm ent. Carbon tubes are being used extensively fo r their high heat transfer ability in the assem bly o f heat exchangers. A ll- carbon centrifugal pum ps are being made, together w ith sm all vessels, cylindrical tower sections, valve bod
ies, fittings and p ip es and a variety o f other fabricated form s.
Concrete— M any w ays have been developed fo r the use o f concrete in tanks and vessels fo r liquids. M any p roprietary com pounds have been in
troduced for waterproofing concrete and for m aking it p roof against other substances. A lthough some o f these were based on rubber, m any now ob
tainable with greater or lesser d if
ficulty are plastic-base m aterials. F or exam ple, a new coating fo r concrete, wood or m etal is made from a fu r
fural ty p e p lastic said to be obtain
able in quantities lim ited only by present production equipm ent. F ilm s o f this coating, built up by a num ber o f brush applications, are thick enough fo r use in contact with all solvents, mineral and oxidizing acids in moderate concentration, vegetable and m ineral oils and high octane fuels, according to the m anufacturer.
This coating, known as Tygon F , is intended for use up to 350 deg. F.
F o r other applications o f concrete tanks, lin in gs o f chemical stoneware and porcelainware, or o f structural carbon, m ay be used where the service is too severe for coatings. M ost o f the cem ents required fo r la y in g up these lin in gs can be secured w ithout difficulty, as well as the bituminous- base typ es o f sheet lin in g material which are som etim es em ployed as a cushion and liquid proofing between the tile and the concrete wall.
O w ing to m etal shortages, cement- asbestos p ip e has come into great de
mand, particularly for the handling o f w ater and m ildly corrosive solu
tions. as w ell as for fum e ducts and
s o — y . S E P T E M B E R 191,2 • C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G
stacks. F o r more severe duty, cement- asbestos p ip e is now being produced w ith resin-base coatings designed for a variety o f degrees o f service severity. Several m anufacturers su p p ly cem ent-asbestos pipe, together with a variety o f fittings and coup
lin gs fo r working pressures up to 150 lb. per sq.in. or even higher.
Chemical S to new are — Chemical stonew are, one o f the old standbys o f the chemical industry, and its newer cousin, chemical porcelainware, are produced in all o f the form s in which structural carbon is available, as well as some additional form s which are possible because o f the bet
ter w orking properties o f clays as compared with carbon during the form ing stage. F or exam ple, large single-piece storage vessels are built in sizes to several hundred gallons.
Chemical stoneware is resistant to all corrosive agents with the exception o f hydrofluoric acid, and in some modifications has good resistance to heat-shock. R ecently developed types are much superior to the earlier grades in heat transfer and, w ith proper installation and use, modern materials o f these typ es are not un
duly fragile.
Enam el— Enam els, particularly the highly acid-resisting glass enamels which are p ro o f again st all acids ex
cept hydrofluoric (and som etim es phosphoric), are tim e-tried m aterials for producing an acid resisting coat
in g on the more readily available base metals, including cast iron and low- carbon steel. A wide variety o f processing equipm ent can be pro
duced in glass-enam eled m etal, in cluding kettles in all sizes up to 2,000 gal., or even larger; valves, pipes and fittin gs; storage tanks;
stills and colum ns; pans and ev a p orators; and heat exchangers. V es
sels are regularly built fo r internal pressures as high as 300 lb. per sq.
in., w hile experim ental autoclaves have proved successful under internal pressures as high as 1,000 lb., with tem peratures to GOO deg. F .
Glass— Glass is an excellent ex
ample o f an old m aterial fo r which new form s and m any new uses have recently been found through aggres
sive research on the part o f several leading m anufacturers. A n exam ple is the 96 percent silica glass which comes close to fused quartz in its re
sistance to thermal shock.
Industrial glass p ip e has now be
come w idespread, such p ip e being made a t present in diam eters up to 4 in. A n electric w elding process for field erection o f p ip e, now in process o f developm ent, w ill doubtless extend
this application much farther. The sam e type o f chem ically resistant, low -expansion glass has been em
ployed in the m anufacture o f a stand
ard design o f all-glass centrifugal pum p, in the fabrication o f distilling column sections in diam eters up to 23 in., in valves, in prccision-bore tubing fo r flowmeters, in cooling coils and heat exchangers, and in other form s.
Glass blocks, in recent years, have become im portant adjuncts to build
in g construction, ow ing to the fa ct that they are capable o f transm itting ligh t w hile at the same tim e they give considerable heat insulation and are capable o f carrying a m oderate load.
A n im portant advantage at present is that window s constructed from such units require m etal only i f movable sashes are to be installed.
F IB R O U S G L A S S
Fibrous glass is another im portant w ay in which this versatile m aterial is m aking a conspieious contribution to the w ar effort. Fibrous glass can be woven into acid- and high-tem pera
ture-resistant filter cloths fo r liquid and gas filtration. I t is being used to a large extent in the m anufacture o f electrical tapes and wire insulations.
I t is available for heat insulation in loose, pelleted, blanket, bait, and also in rigid form s. The last, one o f the new products intended particu
larly fo r cold insulation, is im preg
nated fo r m oisture proofness.
P erhaps the new est form o f glass is the cellular product recently intro
duced fo r insulation, particularly in the low -tem perature field, and for corrosion resisting floats o f various kinds. This product is a foam y form o f glass, the bubbles o f which are non-com m unicating, yield in g a m a
terial which is totally im pervious to m oisture absorption. W eigh in g about 10-11 lb. per cu.ft., the new glass has a heat transm ission coefficient o f 0.45 B .t.u. per sq.ft., deg. F ., hour and inch o f thickness and has s u f ficient strength to im part considerable structural rigid ity and load-carrying capacity.
One novel use for glass has re
cently been suggested and appears to have possibilities as a war-tim e sub
stitute fo r large metal pipe intended fo r operation at high pressures. The scheme is to blow or otherwise form p ip e o f suitable diam eter and incase it in concrete to give adequate strength for such applications as over-land pipelines. Another sugges
tion fo r the same use is to substitute terra cotta pipe fo r glass, likew ise in
casing the terra cotta in concrete for strength.
P a in t s and Coatings— Chlorinated rubber is under allocation and hence is not regularly available fo r chem
ically resistant finishes. R esin coat
ings, such as the phenolies, are also scarce but are obtainable on priority ratings and can frequently be used in place o f galvanizing or fo r the im p arting o f corrosion resistance to equipm ent constructed o f the more p len tifu l m aterials. Som e d ryin g oils, resins and pigm ents are critical but adequate substitutes are available for use by the p ain t industry in the m anufacture o f m ost ordinary pro
tection m aterials.
Plastics— The range o f plastics now produced is extrem ely broad, but it is significant that several o f these are required directly by the war pro
gram. F or exam ple, acrylic and m ethacrylate resins, recently used to a considerable extent in pump ends and step valves fo r proportioning pum ps and in a variety o f small equipm ent where v isib ility o f the con
tents w as necessary, are now goin g largely into airplane cockpit covers and bomber windows. Listed by the W P B in Group I (th e scarcest m a
terials) are the phenol-form aldehyde, polystyrene and polyvin yl chloride plastics, arid in Group I I (the som e
what less scarce m aterials), the urea- form aldehyde, vinyl, and vinylidine chloride plastics. Nevertheless, when they can be secured on sufficiently high priority, some o f the polyvinyl, v in yl and vinylidine derivatives are being offered in interesting form s for substitution fo r m etal pip es. Three such typ es include Saran, a vinylidine chloride derivative, T ygon, a vinyl chloride product, and R esistoflex, a p olyvin yl alcohol derivative.
Saran is now being made in pipe sizes to 2 in. The m aterial can be cut and threaded, coupled w ith com pres
sion-type couplings, oi’ welded by heating the adjacent ends to the fu s
ing tem perature and then pressing them together. Saran is now being mentioned prom inently as a possible substitute fo r brass and copper pipe in general p ip in g applications. The m aterial is suitable fo r tem peratures u p to about 175 deg. F . and is said to be satisfactory fo r contact with brines, hydrocarbons, solvents, or
ganic compounds, acids and alcohols, except cyclic oxygen com pounds and concentrated alkalis. Tygon is said to be more resistant to oxygen-contain- in g com pounds and strong alkalis, but is un satisfactory with solvents such as benzol and chlorinated hydro
carbons. This material also is a p p li
cable at tem peratures up to about 175 deg. F . R esistoflex, which is suitable
C H E M IC A L & M E T A L L U R G IC A L E N G IN E E R IN G • S E P T E M B E R 19!,2 . !)— 91
