THE INDIA RUBBER WORLD 



lAucusT 1, 1920. 



Construction of Steam Hose. 



Fv John M. Bierer; 



STEAM HOSE caii be constructed with a seamless machine-made 

 tube, or with a tube plied from calendered stock. Further- 

 more, the hose can have for its fabric element a duck of 

 given weight and number of plies or a combination of plied duck 

 and one or more plies of braid. To determine whether it is 

 more satisfactory both to user and to manufacturer to make a 

 seamless or a plied tube, and to make a simple multiple-ply duck 

 construction or a combination duck and braid construction, three 

 series of tests, carried out individually and independently by The 

 B. F. Goodrich Co., The Goodyear Tire & Rubber Co., and the 

 Boston Woven Hose and Rubber Co., have been made, the results 

 of which are here offered. 



The actual steam hose tested by the three investigators was 

 obviously of different material, particularly as to compounds, so 

 it is most reasonable and enlightening to survey the different 

 series separately in order not to make the materials a factor 

 in any comparison of constructions. 



The tests by the Goodrich experimenters endeavored to com- 

 pare both seamless with plied tubes and simple duck with duck- 

 braid construction. AH samples were is^-inch inside diameter, 

 with tube %-inch thick, cover 1/32-inch thick, duck 20 ounces 

 per square yard and braid IZVj yarn. The hose was tested in a 

 vertical position (so as not to have condensed steam present), 

 under intermittent steam pressures, ten hours under pressure and 

 two hours' rest until failure. 



The results of the Goodrich tests are suinniarized in Table I. 

 Each result represents an average of five individual samples of 

 each construction. 



Sample B was of distinctly lighter weight than A or C, so it 

 is not surprising that failure occurred earlier than the A and C 

 samples, which were coinparable to each other. C and D were 

 different only in the construction of tube, so that the longer 

 service of C was undoubtedly due to the absence of seams, joints, 

 or plied surfaces, which tend to open up. Similarly, A and C 

 were different in fabric construction, with the same tube, so that 

 the better endurance of C can safely be laid to the superiority of 

 the simple plied duck to the braid and duck construction. 



It takes little studying of these experiments to notice two 

 facts already known to many familiar with steam hose. The 

 steam hose with seamless tube lasted about half again as long 

 as that with a plied tube; and likewise the hose with simple 

 duck of sufficient plies lasted about half again as long as the 

 ho?e with a combination of duck and braid. 



Summarizing the experiments of The Goodyear Tire & Rubber 

 Co., there appears a series of similar results. Table II repre- 



Table I.— Results Obtained in Tests by The B. F. Goodrich Co. 



Sample. 



A B C D 



Number of plies of duck 3 4 6 6 



Number of plies of braid 2 



Tube Seamless Seamless Seamless Plied 



Endurance under 60 lb. pressure, 



hours 2261 904 31 43 2170 



sents an average of live individual samples of each construction. 

 Comparison is offered in this series also of seamless and plied 

 tubes, of duck and duck-braid constructions, and of expansion 

 and contraction measurements as well. Like the Goodrich tests, 

 the hose was tested ten hours under pressure and two hours' rest 

 until failure. 



Owing to details of manufacture, there is necessarily not 

 found the same percentage ratios of endurance among the vari- 



'Publishcd by courtesy of the American Society for Testing Materials. 

 Paper read at the annual meeting of the Society at Asbury Park, New 

 Jersey, June 22-24, 1920. 



=Chemist, Bostcn Woven Hose & Rubber Co., Cambridge. Massachusetts. 



ous constructions that were found in the Goodrich tests, but 

 inspection of the results will reveal certain facts more important 

 than this detail. The hose with the seamless tube C outlasted 

 that with the plied tube D and the hose with the simple plied 

 duck construction C outlasted that with a combination of duck 

 and braid E. These results, though not so strikingly shown, are 

 in accordance with those obtained in the Goodrich experiments. 

 A further feature should be noted, that though the expansion in 

 lateral dimensions and contraction in length are favorable to the 

 duck-braid construction, the difference is so small between the 

 two styles that any real and practical superiority for the braided 

 hose would be negligible in practice. 



The next experimental data to show divergence among the con- 

 structions are those obtained at the Boston Woven Hose & Rub- 

 ber Co. laboratories. In order to determine the relative value of 

 a hose with simple plied duck and hose with a combination of 

 duck and braid, and to determine the relative value of seamless 

 tubes and plied tubes, the following constructions were given pro- 

 Table II. — Results of Experiments of The Goodyear Tire & 

 Rubber Co. 



Number of plies of duck.. 2 4 6 6; 



Number of phes of braid. . 2 0: 



Tube Seamless Seamless Seamless Plied Sean 



longed tests. All hose was of 1-inch inside diameter, J^^-inch 

 tubes. O.OSO-inch covers, and was tested in 3-foot lengths. Two 

 series of tests were carried out : the first at 60-pound steam 

 pressure intermittently 124 hours on and 44 hours' rest, the second 

 continuously at 180-pound pressure, both until failure. Eight 

 individual samples were tested in each series and the results sum- 

 mariztd are an average of these : 



For a given fabric construction, hose with seamless tubes A 

 lasted about one-fifth again as long and B almost twice as long 

 as those with plied tubes C and D. Furthermore, for the same 

 style of tube, hose with simple plied duck A lasted half again as 

 long and C over twice as long as those with duck and braid con- 

 struction B and D. 



In these tests, owing to particularly careful workmanship on the 

 samples, failure was not due primarily to separation of the seam 

 or joint on the inner surface of the tube. But in the ordinary 

 process of manufacture, without such undue care and special at- 

 tention, the plied tube is always a danger, and this splitting and 

 opening up of the tube is practically a fatal objection to the suc- 

 cess of any hose by this method. This series is a clear case of 

 superiority of seamless tubes over plied tubes, and of simple plied 

 duck over a combination duck and braid construction. 



Table III.— Results Obtained by the Boston Woven Hose & 



Number of plies of duck 

 Number of plies of braid 



Tube 



Endurance under 60-lb. i. 



pressure, hours 



Endurance under ISO-lb. 



pressure, hours 



CONCLUSIONS. 



Three different experimental laboratories, working individually 

 and independently, found consistent results in an effort to de- 

 termine the relative values of seamless and plied tubes, and of 



