GLASS-LINEDSTEEL EQUIPMENT P. S. BARNES The Pfaudler Company, Rochester, New York
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(Above) GLASS-LINED STEELSTORAGE TANKS (Right) COMPLETE GLASS-LINED STEELDISTILLATION AsSEMBLY-STILL, CONDENSER, RECEIIVERS, AND INTERMEDIATE PIPINQ 378
included in glass-lined e q u i p m e n t . The maximum steel thickness for the shell will rarely exceed 0.75 to 1 inch; this limit is imposed by conditions existingin the process of glass application. All openings should be flanged rather than threaded, so as to afford full protection against corrosion.
T w 0-G AL’LO N GLASSLINEDLABORATORY STILL
GLASS-ENAMELED steel agitators will always be of the vertical type, driven from above a n d w i t h o u t a bottom step b e a r i n g . The coated N DESIGNING portion of the vertical shaft should g l a s s - l i n e d steel extend within the stuffing box packing equipment, it is necesso as to avoid corrosion from acid sary t o take into convapors. sideration various factors The maximum size of a glass-lined peculiar to this material steel tank or process unit should prefof construction, occaerably be stipulated by the manufacsioned by certain limitaturer, since several factors must be tions d i c t a t e d by its coordinated. First, the severity of the process of manufacture. chemical conditions will dictate the The terms “glass-lined,” exact type and formula of glass which ‘ g 1a s s - enamel-lined,” s h o u l d b e specified. In turn, this and “glass-coated” are specification will limit the maximum v i r t u a l l y synonymous size of an individual piece to which and refer to c o m p l e x this coating can be applied with the borosilicates of high acid requisite degree of p e r f e c t i o n . Still r e s i s t a n c e which are another factor may be the size of the fused into thesteel. The available furnace in which the glass is base material is highapplied, by the method necessary for quality open-hearth steel the type of coating just specified. plate which contains less THOUSAND-GALLON JACKETED GLASS-LINEDREACTION KETTLEWITH AGITATOR Where necessary, a 11ow a n c e should than 0.15 per cent carbon be made for a n o m i n a l a m o u n t of and is free from laminawarpage, such as in large open units and tions and slag mots. a t flanges, which unavoidably occurs a t the -high furnace Where pressures are involved, as will normally be the case temperatures which are employed. with process equipment, the design conforms to the A. S. M. E. code for unfired pressure vessels (paragraphs U97 to U109, inclusive). In some cases state and city codes impose additional requirements. I n determining plate thickness to withstand pressure, it is good practice to employ a higher safety factor than is demanded by the code, since this ensures against movement of the shell, under pressure change, that might tend to fracture the fused-in lining of glass. Obviously this applies only to coated surfaces and not to plain metal portions of the equipment such as steam jackets. Here normal safety factors may be employed. Thickness of the steel must be approximately uniform for all coated parts of any given unit. This is essential for proper fusion, subsequent annealing of the glass enamel, and JACKETED GLASS-LINED STEELEVAPOelimination of localized stresses in the steel shell. Sharp RATING DISH corners must always be avoided, making the radii as long as possible. On this account rectangular shapes are usually As a rule, manufacturers of glass-lined steel equipment undesirable for equipment intended for chemical service. The steel shell will always be butt-welded, with gas or require that complete fabrication be carried out in their electric welds a t the discretion of the manufacturer, but never own shops so as to control rather exacting requirements as riveted or lap-welded, All inside welds are ground smooth. to quality of steel and welding. Where high-pressure steam jackets are involved, allowance RECEIYED February 16, 1937. should be made for the fact that jacket stay-bolts cannot be 379
