Kaj je cevni načrt?
Glavna funkcija cevi je prenašanje tekočine pod tlakom, zato je njihov notranji premer njihova kritična dimenzija. Ta kritična dimenzija se imenuje nazivna vrtina (NB). Očitno je, da je za cevi, ki vsebujejo tekočine pod tlakom, pomembna debelina stene in s tem pomembna trdnost cevi. Debelina stene je izražena z „urniki“, referred to as pipe schedules. The pipe schedule is abbreviated as & nbsp;SCH. For a given size and schedule the thickness of the pipe is fixed and defined in the applicable ASME standard. Other than the pipe schedule, pipe thickness can also be specified in & nbsp;mm & nbsp;or & nbsp;centimetrov & nbsp;to the value corresponding to that specified in the ASME standard.
Kateri standardi velikosti vladne cevi?
V naftni in plinski industriji ter z njo povezanimi industrijami na nižji stopnji so najpogostejši standardi
– ASME/ANSI B 36.10 Welded and Seamless Wrought Steel Pipe, and
– ASME/ANSI B36.19 Stainless Steel Pipe
Ali se razpored cevi spreminja z velikostjo cevi?
Pri vseh velikostih cevi zunanji premer ostane relativno stalen. Zato vsak razpored sprememb, tj debelina stene, vpliva samo na notranji premer. Ko se število urnikov povečuje, se debelina stene povečuje in dejanska izvrtina se zmanjša.
STD & nbsp;is identical to & nbsp;SCH 40 & nbsp;for NPS 1/8 to NPS 10, inclusive. & nbsp;XS & nbsp;is identical to & nbsp;SCH 80 & nbsp;for NPS 1/8 to NPS 8, inclusive. & nbsp;XXS & nbsp;wall is thicker than & nbsp;SCH 160 & nbsp;from NPS 1/8″ to NPS 6″ inclusive, and & nbsp;SCH 160 & nbsp;is thicker than & nbsp;XXS & nbsp;wall for NPS 8″ and larger.
Cevni razporedi cevi
Debelina sten, povezana z določenim načrtom, je odvisna od velikosti cevi, kot je razvidno iz spodnjih grafov za nekatere pogostejše cevi iz ogljikovega jekla.
Stainless steel pipe is most often available in standard weight sizes (noted by the “S” designation, for example “NPS SCH 10S”). However stainless steel pipe can also be available in other schedules.
Abbreviations used: & nbsp;NPS– Nominal Pipe Size, & nbsp;Opomba & nbsp;– Nominal bore, & nbsp;STD & nbsp;– Standard, & nbsp;XS & nbsp;– Extra Strong, & nbsp;XXS & nbsp;– Double Extra Strong.
NPS | N.B. | O.D. | 10 | 20 | 30 | STD | 40 | 60 | XS | 80 | 100 | 120 | 140 | 160 | XXS |
1/8 | 6 | 10.3 | 1.24 | – | 1.45 | 1.73 | 1.73 | – | 2.41 | 2.41 | – | – | – | – | – |
1/4 | 8 | 13.7 | 1.65 | – | 1.85 | 2.24 | 2.24 | – | 3.02 | 3.02 | – | – | – | – | – |
3/8 | 10 | 17.1 | 1.65 | – | 1.85 | 2.31 | 2.31 | – | 3.2 | 3.2 | – | – | – | – | – |
1/2 | 15 | 21.34 | 2.11 | – | 2.41 | 2.77 | 2.77 | – | 3.73 | 3.73 | – | – | – | 4.77 | 7.47 |
3/4 | 20 | 26.67 | 2.11 | – | 2.41 | 2.87 | 2.87 | – | 3.91 | 3.91 | – | – | – | 5.56 | 7.82 |
1 | 25 | 33.4 | 2.77 | – | 2.90 | 3.38 | 3.38 | – | 4.55 | 4.55 | – | – | – | 6.35 | 9.09 |
1.1/4 | 32 | 42.16 | 2.77 | – | 2.97 | 3.56 | 3.56 | – | 4.85 | 4.85 | – | – | – | 6.35 | 9.7 |
1.1/2 | 40 | 48.26 | 2.77 | – | 3.18 | 3.68 | 3.68 | – | 5.08 | 5.08 | – | – | – | 7.14 | 10.16 |
2 | 50 | 60.32 | 2.77 | – | 3.18 | 3.91 | 3.91 | – | 5.54 | 5.54 | – | – | – | 8.74 | 11.07 |
2.1/2 | 65 | 73.02 | 3.05 | – | 4.78 | 5.16 | 5.16 | – | 7.01 | 7.01 | – | – | – | 9.52 | 14.02 |
3 | 80 | 88.9 | 3.05 | – | 4.78 | 5.49 | 5.49 | – | 7.62 | 7.62 | – | – | – | 11.12 | 15.24 |
3.1/2 | 90 | 101.6 | 3.05 | – | 4.78 | 5.74 | 5.74 | – | 8.08 | 8.08 | – | – | – | – | 16.15 |
4 | 100 | 114.3 | 3.05 | – | 4.78 | 6.02 | 6.02 | – | 8.56 | 8.56 | – | 11.12 | – | 13.49 | 17.12 |
5 | 125 | 141.3 | 3.40 | – | – | 6.55 | 6.55 | – | 9.52 | 9.52 | – | 12.7 | – | 15.87 | 19.05 |
6 | 150 | 168.3 | 3.40 | – | – | 7.11 | 7.11 | – | 10.97 | 10.97 | – | 14.27 | – | 18.26 | 21.95 |
8 | 200 | 219.1 | 3.76 | 6.35 | 7.04 | 8.18 | 8.18 | 10.31 | 12.7 | 12.7 | 15.08 | 18.26 | 20.63 | 23.01 | 22.22 |
10 | 250 | 273 | 4.19 | 6.35 | 7.80 | 9.27 | 9.27 | 12.7 | 12.7 | 15.08 | 18.26 | 21.44 | 25.4 | 28.57 | 25.4 |
12 | 300 | 323.9 | 4.57 | 6.35 | 8.38 | 9.52 | 10.31 | 14.27 | 12.7 | 17.47 | 21.44 | 25.4 | 28.57 | 33.32 | 25.4 |
14 | 350 | 355.6 | 6.35 | 7.92 | 9.53 | 9.52 | 11.12 | 15.09 | 12.7 | 19.05 | 23.82 | 27.79 | 31.75 | 35.71 | – |
16 | 400 | 406.4 | 6.35 | 7.92 | 9.53 | 9.52 | 12.7 | 16.66 | 12.7 | 21.44 | 26.19 | 30.96 | 36.52 | 40.49 | – |
18 | 450 | 457.2 | 6.35 | 7.92 | 11.13 | 9.52 | 14.27 | 19.05 | 12.7 | 23.82 | 29.36 | 34.92 | 39.67 | 45.24 | – |
20 | 500 | 508 | 6.35 | 9.53 | 12.70 | 9.52 | 15.08 | 20.62 | 12.7 | 26.19 | 32.54 | 38.1 | 44.45 | 50.01 | – |
22 | 550 | 558.8 | 6.35 | 9.53 | 12.70 | 9.52 | 15.87 | 22.22 | 12.7 | 28.57 | 34.92 | 41.27 | 47.62 | 53.97 | – |
24 | 600 | 609.6 | 6.35 | 9.53 | 12.70 | 9.52 | 17.47 | 24.61 | 12.7 | 30.96 | 38.89 | 46.02 | 52.37 | 59.54 | – |
26 | 650 | 660.4 | 7.92 | 12.70 | – | 9.52 | – | – | 12.7 | – | – | – | – | – | – |
28 | 700 | 711.2 | 7.92 | 12.70 | 15.88 | 9.52 | – | – | 12.7 | – | – | – | – | – | – |
30 | 750 | 762 | 7.92 | 12.70 | 15.88 | 9.52 | – | – | 12.7 | – | – | – | – | – | – |
32 | 800 | 812.8 | 7.92 | 12.70 | 15.88 | 9.52 | 17.47 | – | 12.7 | – | – | – | – | – | – |
34 | 850 | 863.6 | 7.92 | 12.70 | 15.88 | 9.52 | 17.47 | – | 12.7 | – | – | – | – | – | – |
36 | 900 | 914.4 | 7.92 | 12.70 | 15.88 | 9.52 | 19.05 | – | 12.7 | – | – | – | – | – | – |
40 | 1000 | 1016 | – | – | – | 9.53 | – | – | 12.7 | – | – | – | – | – | – |
