Document 4aBXyNgXeeJaYXOm2dyVQqGJQ

508 CHAPTER 20 / 1952 Guide THERMOSTATIC TRAP, .INCET VAiVE Pig. 47. Typical Convector Connections Fig. 48. Typical Connections to Finned Pipe Convector low pressure or vacuum return. A typical arrangement of a flash leg, with sizes required for varying capacities, is given in Fig. 43. CONNECTIONS TO HEATING UNITS Riser, radiator and convector connections must not only be property pitched at the time they are installed, but must be arranged so that the pitch will be maintained under the strains of expansion , and contraction. These connections may be made by swing joints which permit the ex pansion or contraction to occur under heating and cooling without bending of pipes.-: To take care of expansion in long risers, either expansion-joints of commercial construction or pipe, swing joints are used. : Anchoring of pipes between expansion joints is desirable. Two satisfactory methods of making runouts for .one-pipe systems for either the up-feed or the down-feed type are shown in Fig. 44. Where the vertical distance is limited and the runouts must run above the -floor,: the radiator may -be set on pedestals or raised by means of high legs. - -Two methods of-connecting a unit heater to a one-pipe steam heating system are* illustrated in Fig; 2 (and also in Fig. 5 of Chapter 24). Steam Heating Systems 509 Fig. 51. Typical Connections to Finned Tube Blast Heating Coils of the Steam Distributing or Non-Freeze Type ;Typical;two-pipe radiator connections are shown in- Figs; 45 and 46. While these show top inlet supply connections which are preferred, it is also possible to connect the supply to the bottom of-the radiator.; Short radiators may be connected with top supply and bottom return on the same end. A typical method of connecting convectors is shown in Fig. 47;: Some times the supply valve is omitted on convector connections, and a damper is supplied in the outlet grille for heat control. : A typical connection for finned pipe convectors is shown in Fig. 48.. ; . Typical connections to blast heaters are shown in Figs. 49, 50, and 51. Fig. 52 shows a typical return and connection for blastheaters connected to high pressure systems. A typical two-pipe connection to a unit heater is indicated in Fig. 53. CONTROL VALVES Gate valves are recommended in all cases where service demands that the valve be either entirely open or entirely closed, but they should never Fig. 49. Typical Connections to Finned Fig. 50. Typical Connections to Tube Blast Heating Coils Arranged Finned Tube Blast Heating Coils for Series Flow of Air Arranged for Parallel Flow of Air Fig. 52. Typical Return Connections to Finned Tube Blast Heaters with High Pressure Steam