ASME code number for seamless (steam line) pipe

Hi

U can get all these info from ASME Section II Part A of latest edition and addenda. Either for Seamless pipe ge nerally SA105, SA 106, SA 210 Gr A1, SA 335 P11, P22 or others can be used.

Amit

Chhema Boilers Limited, Chandigarh

I would suggest the following:

"common steam pressure on the industrial application is ranging from 6 barg to 14 Barg..."

a. 2.5" and above, ASTM A53 Gr.B Sch.40 Seamless Pipe is quite acceptable

b. 2" and below, ASTM A53 Gr.B Sch.80 Seamless Pipe

Corrosion attack most likely on weld-joint & flanges connections.

Major damaged on weld-joints & flanged-connections cause by hammering during start-up, due to condensate is not properly drain on the lowest point of the piping system. Expansion joint should consider during steam piping design for proper applications.

regards

The following example explains selection and determination of steam pipe wall thickness (see CR4-Thread dated 06-14-2007)

The pipe wall thickness is determined from the applicable formula of the pertinent ASME B31.1, Power Piping (not B31.3, Process Piping).

Given : Code : ASME B31.1

Design Pressure (P) : 13 bar (188.5 psi), [oper. press. 10 bar (145 psi)]

Design Temperature : 180 ^oC (356 ^oF), [oper. temp. 150 ^oC (302 ^oF)]

Material : ASTM A106 Grade B, Seamless

Nominal Pipe Size : 3 inch

Find : Minimum Theoretical Wall Thickness, t_m & Minimum Nominal Wall Thickness, t

Data : t_m = P D_o / (2 S + 2y P) + C (ASME Code B31.1)

Corrosion Allowance, C = 3 mm (0.11811 in.)

Factor, y = 0.4 (for carbon steel) [ASME Code B31.1, Table 104.1.2(A)]

Joint efficiency, E = 1.0 (for seamless pipe E=1)

Pipe Outside Diameter, D_o = 3.5 inch

Allowable Tensile strength, S @ 356 ^oF=15000 psi (ASME B31.1,Table A-1)

Wall Thickness Tolerance = 12.5% (ASME B36.10 & ASTM A106)

Solution : By substitution into equation,

t_m = P Do / (2 S + 2y P) + C

= (188.5 psi)(3.5 inch)/(2*15000 psi +2*0.4*188.5 psi) + 0.11811 inch

= 0.14 inch (3.6 mm)

Which is the theoretical minimum for wall thickness without allowing for wall thickness tolerance.

Thickness adjusted for wall thickness tolerance, t = t_m / (100%-12.5%)

= 0.14 inch/(1-0.125)=0.14/0.875= 0.16 inch (4.06 mm)

The next greater commercial wall thickness is found from ASME B36.10 to be 0.216 inch (5.49 mm) which corresponds to 3" Sch. 40.

In other words 0.216 inch nominal pipe wall thickness is the commercial wall which, when reduced by the full tolerance of 12.5%, satisfies the code formula for t_m.