1/2" G.I.pipe schedule 20 是意思?

1/2 G.I.pipe schedule 20 是意思? G.I.pipe是什么钢管? G.I.PIPE SCHEDULE 80 This size of the pipe:5/8copper pipe.3/8copperpipe.1/2copper pipe. Pipe Tube Size与Pipe Size有什么区别?一个零件的说明文字如下：Fits 1.9 Tube Size 1 1/2 Pipe Size External to the pipe and remote from the pipe i.e.above ground.这句话怎么翻译啊,不懂唉~ 求管件类型英语翻译快Now, I am looking for carbon steel: HR CR GA GI EG ETP coil, sheet, round bars, pipe, HMS1/2, HMS1, used rails, etc Pipe schedule pipe insert oxygen pipe 在vbs种 for each i in pipe 这段代码能给我讲解下吗,i和pipe分别代表什么 matlab 中while 循环问题clear all;i=1;x(i)=4/9;g(i)=4/9;error(i)=4/9;while error>=0.1 g(i+1)=-(1/9)*(g(i)^3-6*g(i)^2-4); g(i)=g(i+1); disp('g(i+1)'); disp(g(i+1)); error=g(i+1)-error; disp('error');i=i+1; end为什么运行的 英语翻译1 Pipe sch 40,20 dia ASTM 106 GR-B OR API 5L GR-B,Seamless Beveled End.20ft Long 8 lg 2 Pipe sch 40,12 dia ASTM 106 GR-B OR API 5L GR-B,Seamless Beveled End.20ft Long 2 lg 3 Pipe sch 40,10 dia ASTM 106 GR-B OR API 5L GR-B,Seamless Beve 1)Stainless Steel Seamless Pipe ASTM A312 316L Sch-10 Size:2 qty:2000 Ft 3 qty:2000 Ft 4 qty: 一道英文版的物理题,大致图形如下.（题目来自新加坡某中学的物理提纲）The diagram below shows a solar heating system.（a）Write down the process by which energy is transferred,1)From the sun to the pipe.2)From the pipe t 英语翻译Weld on the pipe body to be ground flush with pipe body for 2m below square shouldered connector or load ring for latching of the elevator. G.I.