Document zQoZwQVXkjj11BEDxDwgzE4q6

American Society, of Heating and Ventilating Engineers Guide, 1930 PIPING CONNECTIONS Hartford Return Connection The Hartford return connection illustrated in Fig. 7 and in other piping layouts in this chapter is, recognized as safer and preferable to the use of check valves. In using this connection, the wet return connects through the shortest possible horizontal pipe 2 in. below the normal boiler, water line into the pipe which joins the boiler outlet and boiler inlet on the boiler side of the stop valves. By this arrangement, if a careless operator should close the boiler outlet valve and should forget to close the boiler inlet valve, no water below the level of the inlet con nection to the loop could leave the boiler. Connections to Mains- Fig. 8 shows two methods of taking off branches from mains oa onepipe systems. They apply equally well, however, to other systems of rTHESE CDMtCMS SHOULD BE AS SHOUT AS PBOCAL USHG AS FEW-, \ TUBUS AS POSSIBLE. THE SIZES SHOULD PBEFEBAHE BE NOT SHALLEB THAU GIVEN W TABLE BELOW. GBATE AEEA PIPE SIZE A SO- FEET OB LESS------------- IW A SO. FEET TO B SQ FEET.------IK 15 sa FEET OB. MOBE------------ A' Fig. 7. THESE PIPES MM EE AHY SIZE CONSOEBED PBOPEB FOB FEEDING1 BOOKS AHO LESS THAU STEAM CONUECTIOHS M TABLE ABOVE Connecting Two Boilers Using the Hartford Return Connection up-feed piping. On one-pipe plants the branches are always made one pipe-size larger than the risers or the radiator connections which they serve. The method of carrying a main past an obstructing beam shown in Fig. 9 may be used advisedly with any system of piping. Fig. 10 shows a detail of piping at the end of a single-pipe main or at any pioint where it becomes desirable to: rise for a fresh start at a higher level, the steam rising off the top of the main and the water draining down to the wet return below the boiler water line. If the detail shown in Fig. K) is used at the end of the main, an air valve must be installed above the Water line. Where it is desired to reduce the size of a supply main, an eccentric fitting always must be used,.as shown in Fig. 11, or a reducing elbow must be installed, as in Fig. 12, so that perfect drainage is accomplished. These details also apply to any other system of steam piping. A handy rule for cutting the proper length of offset pipe is illustrated in Fig. 13. 360 Chapter 20--Piping for Steam Heating Systems Piping Connections {or Vapor and Vacuum Systems In Figs. 14 to 19, inclusive, are illustrated some of the piping, details which are recommended in connection with vapor and vacuum heating. Figs. 14 and 18 show methods of draining and venting the ends of supply mains where a return below the boiler water line is used. Fig. 19 shows the same detail where the return main is above the water line. Fig. 15 shows the method of draining the ends of long branches from supply Fig. 8. Acceptable and Preferred Methods of Taking Branch from Main Fig. 9. Looping Main Around Beam ra . I ECCENTKRHIC REDUCING J]l |-- 6------- 1 f COUPLING. jS=0==il^=: Fig. 11. Practical Method of Reducing Size of Main Dripping Main Where It Rises tctHigher Level Fig. 12. Reducing Size of Main at Swing Connection . TO FNJUXGTtiC - UULTIDLY K BY COUSIANT FOR ANGLE, a. Fig. 13. Constants for Determining Proper Length of Offset Pipe mains to risers or to remote radiators. Fig. 16 shows a sediment chamber which will catch debris in any vapor or vacuum system, this being cleaned occasionally, preventing the foreign matter ffbm stopping up or injuring the traps or other mechanisms. Fig. 17 illustrates an approved method for carrying a return main which runs near the floor, past a door. The air in the upper part of the main rises freely over the door, while the water passes in the trench under the door. Figs. 20 and 21 illustrate approved details-of the return pipes leading to vacuum pumps where there must be lifts from low-lying mains up to the pump. These lifts should be avoided wherever possible. 361