Document jyBMR7ynw8GBzQ89Z9JEB1aKQ

498 CHAPTER 23 1949 Guide giving a perfect swing joint when connected to the vertical riser or radia tor connection, whereas the preferred connection does not give this swing without distorting the angle of the pipe. Runouts, are usually made about 5 ft long to provide flexibility for movement in the main. Offsets in steam and return piping should preferably be made with 90-deg ells but occasionally fittings of other angles are used, and in such cases the length of the diagonal offset will be found as shown in Fig. 38. Dirt pockets, desirable on all systems employing thermostatic traps, should be so located as to protect the traps from scale and muck which Steam Heating Systems and Piping . .....MiTSfr..- Runout below floor PLAN 1 499: Fia. 43. Flash Leo Installation fob 80 psi Maximum Steam . Wokking Pressure Table 13. Traps Dimensions Applying to Fig. 43 \ CoNDEN- BATS PEB He., Lb as 70 Psi HP Side . 3 & bS 0 a E s U3 0c PS LP Side Ji CO 8 & <a < Flash FG Leo, IPS Ft. Ik. In. In. In. In. In. ' NESS. In. 200 i 1 21-80 i 300 .} 31-70 f . 700 1 31-70 i 1500 i 61-80 1 2500 1 61-80 it 4000 li- 61-8C 2 8000 2 61-80 2$ 15000 ' 21. & 61-80 21 0-20 A 0-15 \ 0-15 1 0-15 i 0-15 Ilk 0-15 lA 0-15 Ilk 0-15 4 4 4 5 8 10 12 .16 . 3 3 3 4 5 6 6 6 6 6 6 6 6 6 6 8 83 83 83 10 4 10 4 12 5 12 5 14 6 s 7 ii 1 i it. i t it i i li 1 1 2H H 2a H 32 333 i 1 I 1 I 8- - 1 Fig. 44. One-Pipe Radiator Connections will interfere with their operation. Dirt pockets are usually made 8 in. to 12 in. deep and, serve as receivers for foreign matter which otherwise would be carried into the trap. They are constructed as shown in Fig. 39. On vapor systems where the end of the steam main is dripped down into the wet return, the air venting at the end of the main is accomplished by an air vent passing through a thermostatic trap into the diy return line as shown in Fig. 40. On low pressure or vacuum systems, the ends of the steam mains are dripped and vented into the return through drip traps opening into the return line. A float and thermostatic type trap is recommended for dripping steam mains and risers as indicated in Figs. 41 and 42. ' The dripping of high pressure mains or of equipment using high pressure steam into low pressure or vacuum returns is generally accomplished by the use of a flash tank or flash leg into which the high pressure trap is arranged to discharge. This tank provides the required space for the flashing from high temperature condensate to low pressure steam to take place. The low pressure steam therein generated is passed directly to the low pressure steam mains and the condensate is discharged through a second trap to the Fig. 45. Two-Pipe Top and Bottom Opposite End Radiator Connections Fig. 46. Two-Pipe Connections to Radiator Hung on Wall X