Pipeline engineering common text symbols are there? A: pipeline engineering commonly used symbols are shown in table 2 - text 7. Table 2 - 7 pipe symbol words commonly used symbol symbol name symbol Dw symbol name symbol 1 pipe diameter, Q2 dm37 heat pipe diameter Du, dn38 heat capacity C3 diameter D, d39 quality constant pressure heat capacity cp4 nominal diameter DN40 quality constant volume heat capacity cv5 pipe radius R, temperature t, & tau r41 facilities; 、θ 6 R42 thermodynamic temperature T7 has pressure bending radius p43 temperature & Delta; t、Δ T8 nominal pressure PN44 quality m9 stress & sigma; The density of 45 & rho; 10 allowable stress [& sigma; 46 quality] heat capacity than & gamma; 11 moment M47 melt & mu; 12 bending moment W48 kinematic viscosity & nu; 13 inertia J49 kinetic viscosity & mu; 14 section coefficient W50 frictional resistance coefficient & lambda; 15 E51 elastic flow coefficient of local resistance & zeta; 16 the velocity V, V, w52 Re17 Reynolds number flow rate Q, Q, L53 flow coefficient & mu; Mass flow rate of 18 G54 chezy coefficient of C19 head H55 line [of] expansion coefficient & alpha; T20 head loss & H, h56 [of] expansion coefficient alpha; V21 hydraulic gradient I, i57 force making hydraulic radius R58 acceleration & alpha; 23 W (work 一) The angular velocity of 59 & omega; 24 power amplitude A25 P60 speed N61 can ( The amount) Efficiency of E26 & eta; 62 thermal conductivity & lambda; 27 plane Angle & alpha; 、β 伽马; 、θ 众人; 63 surface spread factor & alpha; 28 length L, l64 heat transfer coefficient & Kappa; 29 wide, high thermal resistance R30 b65 H, B h66, thickness of palisade structure thermal inertia index D31 S & delta; Kh32 area A, t, T67 hours change coefficient, S68 pipe roughness coefficient n, K33 volume V69 design pressure is P&tau P34 time t70 trials; T71 design temperature, Pe35 cycle allowable pressure PA36 frequency coefficient of cold-drawn f72 & epsilon;