英寸管径标准管径

英寸管径管径 Inch diameter standard diameter 1/8 6mm 1/4 8mm 3/8 10mm 1/2 15mm 3/4 20mm 1 25mm 1-1/4 32mm 1-1/2 40mm 2 50mm 21/2 65mm 3 80mm 4 100mm 5 125mm 6 150mm In short *25.4= metric inches (mm) The diameter (nominal diameter) said, also known as the average diameter (mean outside diameter). This is the reason from the tube wall metal tube is thin, tube diameter and tube diameter not much difference between, so take the tube diameter and the average value of the diameter of the tube diameter as a call. Because the units have metric (mm) and British (inch) distinction, there are the following methods of address. 1., based on the metric system (mm), called DN (metric unit) 2., on the basis of the British system (inch), called NB (inch unit) 3. DN (nominal, diameter) NB (nominal, bore) OD (outside, diameter) 4. [case] Galvanized steel pipe DN50, sch 20 Galvanized steel pipe "NB2", sch 20 5., the outer diameter and DN, NB relationship is as follows: ------DN (mm), --------NB (inch), -------OD (mm) 15-------------- 1/2--------------21.3 20--------------3/4 --------------26.7 25-------------- 1 ----------------33. 4 32-------------- 1, 1/4, -----------42.2 40-------------- 1, 1/2, -----------48.3 50-------------- 2, -----------60.3 65-------------- 2, 1/2, -----------73.0 80-------------- 3, -----------88.9 100-------------- 4, ------------114.3 125-------------- 5, ------------139.8 150-------------- 6, ------------168.3 200--------------- 8------------219.1 The above data is referenced only in ASTM A53. Please note that there are some differences in external diameter with different specifications Nominal diameter, also known as the average diameter. Since the wall of the metal tube is thin, the diameter and diameter of not much difference between, so the average diameter of the tube is worth. Nominal diameter is the metric mm based, called DN (metric unit) For example, DN100 tube, if encountered thin-walled tube, it has to be larger than the diameter of 100mm, but encountered thick walled tube, it will be smaller than the diameter of 100mm. But when calculating, take 100mm. It's also called DN100 The relationship between DN and NB is this: DN/25=DB, such as DN50, is DB2, that is, "2", "1", "=25.4mm" DN15= DN20= Phi Phi 20; 25; 32 DN25=; 40 DN32= Phi Phi 50; DN40=; DN50= 63;... And diameter of the general relationship between nominal... (Note: in metal pipe. The seamless steel pipe diameter) marked by phi, In a simple way, the same type of pipe diameter, diameter larger than DN a number, such as Phi 20 = DN15 Phi 25 = DN20 ...... And so on, very simple and feasible way, you don't want to be too complicated. Look, we all have some doubts about the nominal diameter Let me explain Nominal diameter (diameter), also known as the average diameter: This is the tube from the metal tube, it is very thin, The outer diameter of the pipe is almost the same as the inner diameter of the tube, so the average value of the outer diameter of the pipe and the inner diameter of the pipe is called the diameter. Generally speaking, the diameter of the pipe can be divided into outer diameter, inner diameter and nominal diameter. The diameter, inner diameter of pipe is better understood, seamless steel pipe and metal pipe diameter by the letter D to represent, then additional outer diameter size and thickness, such as diameter of seamless steel pipe 108, a wall thickness of 5MM, denoted by D108*5, is also used outside said, such as De63 plastic pipe, such as reinforced concrete pipe, cast iron pipe, galvanized steel pipe, represented by DN, in the design drawings is generally used to represent the nominal diameter, nominal diameter is a standard in order to design and manufacture and maintenance convenient set artificially, with nominal diameter, tube (or tube) specification name. The nominal pipe diameter and the inner diameter and the outer diameter were not equal, for example: the nominal diameter of 100MM seamless steel pipe post 102*5 and 108*5 several, 108 for the outer diameter of pipes, 5 said that the wall thickness of the tube, therefore, the pipe diameter (108-5-5 = 98MM), but it is not completely equal to pipe diameter minus two times the wall thickness difference, it can be said that the nominal diameter is close to the diameter, but not equal to the diameter of a pipe diameter specifications on the design drawings, so we use the nominal diameter, the purpose is to determine according to the nominal diameter pipe, flange and gasket structure and size connecting dimensions, nominal diameter is represented by the symbol DN, if the diameter of said in the design drawings, piping specifications should also make the table, show that the nominal diameter of a pipe wall thickness. Nominal diameter is the average outside diameter Nominal diameter is neither the inside diameter nor the outside diameter, but a calculation diameter, which reflects the actual water flow capacity of the pipeline. Generally close to the inside diameter. Nominal diameter = diameter + wall thickness average value, this is from the metal tube of the tube is thin, the outer diameter of the tube and the tube is almost the same, so take the outer diameter of the pipe and the average diameter of the pipe as the diameter of the call. Because the units have metric (mm) and British (inch is English inches) distinction, so there are the following name method. 1. nominal diameter DN, in metric (mm) units The 2. NB is based on the British system (inch), which is usually a few inches apart 3. DE indicates that the outside diameter is usually expressed as the plastic tube, and the metric (mm) is the unit. According to the different tubing, the outside diameter range is not the same, but there is probably a standard listed below 5. the outer diameter is related to DN, NB, DE: The nominal diameter of DN (mm) --------NB (inch) - DE diameter (mm) 15-------------------- 1/2 (4 English points) ------------------21.3 20--------------------3/4 (6 English points) ------------------26.7 25-------------------- 1 (1 inches) -------------------33.4 32-------------------- 1 1/4 (1.2 inches) --------------42.2 40-------------------- 1 1/2 (1.5 inches) -------------48.3 50-------------------- 2 (2 inches) -------------------60.3 65-------------------- 2 1/2 (2.) 5 inches) --------------73.0 80-------------------- 3 (3 inches) -------------------88.9 100-------------------- 4 (4 inches) ------------------114.3 125-------------------- 5 (5 inches) ------------------139.8 150-------------------- 6 (6 inches) ------------------168.3 200--------------------- 8 (8 inches) ------------------219.1 The relation here is only the corresponding relation of the specifications, not equal to the relation