Piping codes have? Answer: the pipe - code are shown in table 2 8. Table 2 - 8 pipe symbol symbolic names symbol symbol name symbol 1 saturated steam pipe S40 A2 superheated steam tube OS41 oxygen and compressed air OX3 production steam pipe PS42 liquid oxygen LOX4 live steam pipe DS43 nitrogen N5 heating steam pipe HS44 liquid nitrogen LN6 heating steam pipe TS45 hydrogen HY7 purge steam pipe BLS46 argon AB8 secondary steam pipe SS47 acetylene AC9 waste steam pipe WS48 carbon dioxide CD10 condensate pipe ( Gravity) CW49 gaseous propane pipe ( Liquefied petroleum gas) PG11 condensate pipe ( Pressure flow) CWP50 liquid propane pipe ( Liquefied petroleum gas) H51 LPG12 heating hot water pipes, gas pipe Regardless of the type) G13 heating hot water return pipe HR52 BFG14 blast furnace gas pipe hot water pipe production ( Loop gravity) PH53 coke oven gas pipe COG15 production of hot water ( Circulating pressure flow) DH55 PHP54 converter gas pipe LDG16 living hot water pipes heat generator gas pipe HGG17 living hot water return pipe DHR56 gasifier cold gas pipe CGG18 feed pipe W57 generator water gas pipe WGG19 softened water pipe SW58 mixed gas pipe MIG20 in addition to the brine DMW59 gas pipe NG21 CWS60 circulating water pipes biogas tank MG22 circulating water return pipe CWR61 air vent pipe V23 HC62 oxygen vent pipe hot water pipes containing phenol VOX24 HCR63 hydrogen vent pipe thermal cycle pipes containing phenol VH25 CC64 nitrogen blow-down pipe cold circulation pipes containing phenol VN26 cold circulation return pipe containing phenol CCR65 argon vent pipe VAR27 circular tube CP66 gas vent pipe VC28 P67 carbon dioxide vent pipe pipes VCD29 drain D68 acetylene vent pipe drain PD69 VAC30 production steam vent pipe ES31 continuous sewage pipe CB70 for tubing ( Regardless of the type) O32 regular sewer PC71 return pipe ( Regardless of the type) OR33 overflow tube OF72 kerosene M73 heavy oil tube KO34 supply pipe for pipeline HO35 salt solution tube SA74 heavy oil return pipe HOR36 sulfuric acid pipe SFA75 coke tank T37 hydrochloric acid HA76 emulsion E38 alkali solution, Sodium hydroxide) Pipe SL77 gasoline GO39 expansion pipe EXP78 oil MO