high-pressure hydrogen h>e used without adequate barricades even "though the pressure vessels are protected with suitable stainless steel liners.
PRODUCTION
SAFETY
FORUM
Steel Lining Eliminates Failure of Pressure Vessels Failures .in small equipment using hydrogen at room temperatures and at pressures in excess of 2000 atmospheres, prompted Du Pont's engineering research labs to conduct investigations on the influence of hydrogen on the mechanical properties of high strength steels usually used for the manufacture of high pressure vessels. Du Pont's solution, according to Charles M. Cooper, director of the engineerings labs, is the use of liners that are essentially impervious to the penetration of Hydrogen at elevated pressures. Bursting tests were carried out on pressure vessels using oil as a medium and the results were compared with bursting pressures obtained using hydrogen as the test medium. The steels involved covered a variety of compositions, heat treatments, and wall ratios. In the most striking instances these results showed that pressure vessels suitable for operation under oil at pressures in excess of 7000 atmospheres failed in a brittle fashion under hydrogen at pressures as low as 2000 atmospheres and in periods of time as short as a few minutes. The pressure level at which fail-
For further information on keyed item mentioned here, see coupon on page 2946
ure occurred under hydrogen appeared to be related not only to steel' composition, steel quality, and forging reduction, but also to the specific heat treatment involved in the fabrication of the pressure vessel. The bores of the steel vessels were provided with continuous, shallow, spiral grooves from end to end to prevent any hydrogen pressure build-up between liner and vessel. The most successful of the lining materials tested so far is Type 316 stainless steel. The use of stainless steel liners for periods up to several months was successful in eliminating brittle rupture. In addition, bursting tests carried out on stainless steel vessels in hydrogen indicated that the material failed at the same pressure as was obtained when the tests were carried out with oil. The brittle nature of failures constitutes a serious safety hazard unless proper precautions are taken to protect personnel. Du Pont recommends that under no circumstances should equipment containing
ffW1
©ratory
For l®rg@^csinounts of ^ ^ *
organic*
^en^lschiocyonotcforexo^e
^rit© to Eastman Organic ChemicaSs Department, Distillation Products Industries, 741 Ridge Road West, Rochester 3 , N . Y . ( D i v i s i o n of E a s t m a n K o d a k C o m p a n y ) . T h e r e are m o r e t h a n 3 5 O 0 regularly s u p p l i e d Eastm a n O r g a n i c C h e m i c a l s for s c i e n c e a n d i n d u s t r y . Also . . . vitamins
2942
A
and E . . . distilled monoglycerides . . . high vacuum
equipment
C H E M I C A L
Static C h a r g e in Silica Gel Column Causes Flasli Fire The generation of a static charge in a silica gel column* caused a. sinall flash fire at one of Huinble's Baytown laboratories, according to J. F. Hickerson, Humble Oil & Refining Co. The fire occurred when aromatic contaminants were being removed from iso-octane loy pouring the liquid through a glass column containing silica gel. The column, whictr is 2 inches in diameter and ahout 4 feet long, rested on a ring stand which was grounded. In charging the silica gel t o the column, 2 pounds of 20-200 mesh gel was poured into a 6-inch enameled funnel. The enamel on the edges of the funnel had chipped off, exposing t h e bare metal. When the iso-octane was poixred into the funnel, a flash occurred whicbk fortunately caused no damage either to personnel or equipment. An investigation of trie a-ccident was made and, in duplicating the operation, an explosion meter indicated that during the pouring of the iso-octane th\.ere was no explosive mixture farther than six inches from the surface of the licjuid. Since there was no source of flame i n thfs vicinity, it was suspected that a static charge was present. Measurements were macle under varying conditions of t h e apparatus, using an electronic volt meter. Th.e apparatus was emptied, thoroxjghly dried, and measurements were taker* during and after the time silica gel was introduced. First, one lead to the test meter was grounded, and the other lea:d contacted the surface of the glass columrr and funnelUnder this condition no difference in potential was indicated. Trie outer surface of the column was wrarpped with metal braided ground wire and part of the metal placed inside the column as t h e silica gel was introduced. One lead of the test meter was grounded and the other lead placed in trie silica gel in the column. Under these conditions a. potential of up to 25 volts was indicated on thie test meter. As the lead was removed from the silica gel and approached the worn edge of the enameled funnel, a spark was observed to leap between the lead and tire funnel. It was observed during thie readings that more voltage was indicated on the test meter as the surface area of the column contacting the ground connection was increased, even though the ground connections were made before, during, and after the introduction of silica gel. The same measurements were made while using a glass funnel, and three volts were indicated on the test meter. The use of a bare metal, grounded funnel resulted in no indication o f generation of a static charge even though t h e rest of the apparatus was not grounded. From the series of measurements' it is postulated that a static cliarge was generated as the silica gel contacted the enAND
ENGINEERING
NEWS
ameled surface of the funnel. When the iso-octane was poured, the funnel was pushed over near the grounded ring stand and a spark occurred. The use of a grounded, bare metal funnel in this particular setup would decrease the generation of a static charge to a negligible consideration, according to Mr. Hickerson. However, he asserted, in silica gel installations where more volatile liquids are used, further study should be made, consideration being given to flushing the column with nitrogen and using a closed system to introduce the liquid to preclude the possibility of a flash.
MCA Achievement Certificates Increase in 1951 Certificates of achievement for perfect safety records over the past year have been awarded by the Manufacturing Chemists' Association to 183 United States chemical plants, according to Charles S. Munson, chairman of the association's board of directors. This compares with 159 plants that received certificates last year, Mr. Munson said. The awards are presented annually by the association to member company plants that have worked die previous calendar year without a reportable lost-time or disabling injury. Companies and number of plants receiving certificates based on their 1951 records are as follows: No.
OF P L A N T S RECEIVING CERTIFICATK*
HC^ H C
4 6 1 oo ~2 4 2
28
*
C-OH
Leather
*
Electroplating
Alk/lation Oxidation Acylcttion Esterification
Etberification Arnmonolysis Condensation
Coupling
O K o p p e r s C h e m i c a l D i v i s i o n p r o d u c e s this i m p o r t a n t ciheiriical in t w o commercial grades:
A one-piece bi-colored lens, designed specifically for workers exposed to intense visible light, ultraviolet and infrared radiations, is available from American Optical Co. The lens is hardened for utmost impact protection and is said to have the strength of a single lens. Where one half of the integral lens meets the other half, there is no junction that might collect dirt or foreign matter and obstruct vision. Light streaks are avoided and reflections cannot distract or endanger worker. S 1 NO.
% ^
In Bactericides • Antioxidants Photography • Perfumery • Medkinals
Hydrogenation Halogenation Nitration SuBfonation
Bi-CoSored Lens Protects Eyes From UV and IR Radiations
3 O,
C-OH
A n d Catechol enters into a host of other chemical reactions!
15 1
Established by MCA in 1950 and administered b y the association's general safety committee, the award system is designed to encourage and recognize outstanding safety achievement in the chemical industry, Mr. Munson said. A plant may continue to win an award annually by continuing its no-injury safety record.
V O L U M E
Catechol?
H
18 7 1 2 2 15 1 61 1
American Cyanamid Atias Powder Catalin Corp. Celanese Corp. Commercial Solvents Davison Chemical Dow Chemical D u Pont B. F . Goodrich Chemical Harsh aw Chemical Koppers Co. Lion Oil Mathieson Chemical Merck Monsanto Pennsalt Procter & Gamble F . S. Royster G u a n o Spencer Chemical Stauffer Chemical Victor Chemical Visking Co. Westvaco Chemical
HAVE YOU TRIED Kcipp@rs
»
»
C a t e c h o l C.P.—with a m i n i m u m p u r i t y of 9 9 . 0 % , i n t h e f o r m of crystalline granules. C a t e c h o l R e s u h l i m e d — w i t h a m i n i m u m p u r i t y of 99.6%, i n trie form of g l i s t e n i n g w h i t e n e e d l e s . C a t e c h o l C.P. is useful in chemical m a n u f a c t u r i n g and processing, w h i l e C a t e c h o l R e s u b l i m e d has m e d i c i n a l and p h o t o g r a p h i c a p p l i c a tions. T h e r e a d y availability of t h i s o r g a n i c c h e m i c a l recoirunends its f u r t h e r study in y o u f laboratories. F o r m o r e i n f o r m a t i o n , write for y o u r c o p y of K o p p e r s B u l l e t i n C-9-127 w h i c h gives full details o n p r o p e r t i e s , uses a n d r e a c t i o n s of Catechol.
KOPPERS C O M P A N Y , Chemical Division
JULY
14,
1952
INC.
* Pittsburgh
19, Pea.
2943
