. Machine design. PIPE FITTINGS. 41 each size were tested to destruction by hydraulic pres-sure. The following table gives a summary of the resultsobtained. The values which are starred in the tablewere obtained from fittings which had purposely beencast with the core out of center so as to make one wallthinner than the other. These values are not includedin the averages. TABLE X. BURSTING STRENGTH OF STANDARD SCREWED FITTINGS,PRESSURES IN POUNDS PER SQUARE INCH. SIZE. ELBOWS. SIZE. TEES. AVERAGE. li 3400 3300 3300 3333 H 3400 3200 2800* 3300 2 2500 2800 2500 2600 8* 2400 2100* 2500
. Machine design. PIPE FITTINGS. 41 each size were tested to destruction by hydraulic pres-sure. The following table gives a summary of the resultsobtained. The values which are starred in the tablewere obtained from fittings which had purposely beencast with the core out of center so as to make one wallthinner than the other. These values are not includedin the averages. TABLE X. BURSTING STRENGTH OF STANDARD SCREWED FITTINGS,PRESSURES IN POUNDS PER SQUARE INCH. SIZE. ELBOWS. SIZE. TEES. AVERAGE. li 3400 3300 3300 3333 H 3400 3200 2800* 3300 2 2500 2800 2500 2600 8* 2400 2100* 2500 2450 3 1400* 1900 1800 1850 3i 1200* 1500 1800 1650 4 1800 2100 1700 1867 U 1100* 1400 1400 1400 5 1700 1300* 1500 1600 6 1400 1500 1100* 1450 7 1400 1400 1500 1433 8 1200* 1400 1300 1350 9 1300 1400 1200 1300 10 1100 1300 1200 1200 12 1100 1000 1100 1067 * Made with eccentric core. 42 MACHINE DESIGN. These tests show a large apparent factor of safetyfor any pressures to which screwed fittings are usuallysubjected. The failure of such fittings in practice must be at-tributed to faulty workmanship in erection, such asscrewing too tight, lack of allowance for expansionand poor drainage. The average tensile strength of the cast-iron used inthe above fittings was 20000 lbs. per sq. in. Problems. 1. Determine the bursting pressure of a wrought iron steam pipe 6 inches nominal diameter. (a) If of standard dimensions. (b) If extra strong. (c) If double extra strong. 2. Compare the abov
Size: 2386px × 1047px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1906
