【正文】 MPa。 it refers to the media volumetric flow safe allowable stress of the steel products at certain temperature, MPa. Nominal pressures for the general homemade steel products are listed in APPX ~. Water pressure test Water pressure test is used in testing the strength of pipe and its fittings as well as pipe system39。s nominal pressure The allowable working pressure and nominal pressure of the pipes and fittings can be converted as the equation below: ［ｐ］＝ PN xt][ ][ δ δ () Where: [p] The allowable working pressure, MPa。s maximal design capacity operating condition shall be adopted. (13) Blowdown line of safety valve Design temperature for the blowdown line shall be selected from the corresponding statistics according to the blowdown line39。s rated pressure shall be adopted。s maximal design capacity operating condition shall be taken. (9) Condensate pipe Maximal working temperature of the condensation water after the low pressure heater shall be taken. (10) Drainage pipe of the heater The corresponding saturation temperature according to the heater extraction line39。s maximal working temperature at the temperature reducing device outlet shall be taken. (6) Aerated water pipeline connected to the monopipe boiler starting vessel The maximal possible working temperature that the pipeline can have during all segregator operation conditions shall be taken. (7) High pressure feed water pipeline The maximal working temperature of the high pressure feed water after using the high pressure heater. (8) Low voltage feedwater piping For the constant voltage deaerator system, the corresponding saturation temperature of the deaerator39。 12 Regulated extraction line takes the maximal working temperature of the exhaust gas. (4) Blowdown line of the backpressure steam turbine Steam exhaust39。s extraction line Nonregulated extraction line take the extraction steam parameter under the steam turbine39。s maximal design capacity operating condition。s normal operation. Suggested temperature deviation is 5℃ . (2) Reheat steam pipeline High temperature reheat pipe shall take the steam rated working temperature at the boiler reheater outlet plus the allowable temperature deviation during the boiler39。s rated pressure shall be adopted. (13)Exhaust pipe after the safety valve It shall be determined according to the hydraulic calculation result of the blowdown pipe. Design temperature It refers to the maximal working temperature of the media inside the pipe. The design temperature for the main pipe shall be selected according to the following specifications: (1) Main steam line It shall take the steam39。s heatup extraction pressure at the maximal design capacity operating condition of the steam turbine. When the pipingmain scheme system is adopted, the restriction orifice and its previous pipeline shall adopt the design pressure of corresponding high pressure feed water pipe。 for 11 pipeline after the stop valve, the constant voltage deoxidizing system shall take the rated pressure of the deaerator。s maximum water level to the pipe coupling points。s drainage pipe It shall be times of the extraction pressure under the steam turbine39。 The pipeline at the condensate pump39。s interface section and it shall be no lower than 。 From stop valve at the pump outlet to entrance of the boiler economizer, the pressure shall take the sum of the pump water inlet side pressure and times of pump popping pressure at the pump39。s water inlet side pressure respectively。s extraction line 9 Nonregulated extraction line39。 when the pressure is lower than 3% of the nominal pressure, it will not be considered. The design pressure of the main pipe is applicable in the following specifications: (1) Main steam line Nominal working pressure at the boiler superheater exit or working pressure at the maximumcontinuous evaporative capacity of boiler shall be taken. When the boiler and steam turbine permits the pressure to be 5% greater (5% OP for short), 5% overpressure value shall be added. (2) Reheat steam pipeline The pressure shall be times of the pressure cylinder exhaust pressure under steam turbine39。s) media critical mass flow velocity L m overall pipeline stretched length λ pipeline friction coefficient Rξ Reynolds number ξ resistance coefficient of pipeline+ Σξ 1 pipeline‘s general coefficient of local resistance e pipe equivalent roughness g m/s2 acceleration of gravity k steam adiabatic exponent a media mass flow velocity ratio before and after the local changes of the pipeline H1 m height mark of the pipe initial end H2 m height mark of the pipe terminal end Pat Pa atmospheric Pressure Pop N working load of the spring P N installation load of the spring Pmax N maximal allowable load of the spring λmax mm maximal allowable distortion of the spring Hop mm spring working height Het mm spring fitting height H0 mm spring free height ΔZt mm thermal walking value of the pipe‘s supports and hangers along the vertical direction K mm/N spring coefficient μ friction coefficient Lmax m maximal allowable spacing of the supporter and hanger I cm4 pipe section moment of inertia q kN/m self weight of the pipeline 6 per unit length E20 kN/mm2 elastic modulus of the steel products at 20℃ Et kN/mm2 elastic modulus of the steel products under design temperature αt 106/℃ linear expansibility of steel products at working temperature ζ MPa shear Stress Hf mm weld height hu mm effective throat thickness X mm axial displacement absorbed by the expansion joint Y mm transversal displacement absorbed by the expansion joint X0 mm maximal pensation quantity of the hose balance by the expansion joint Y0 mm maximal pensation quanti