nd鋼管外徑和承受壓力求壁厚計(jì)算方法：nd鋼管外徑、規(guī)格、壁厚求能承受壓力計(jì)算方法(鋼管不同材質(zhì)抗拉強(qiáng)度不同) 壓力=(壁厚*2*鋼管材質(zhì)抗拉強(qiáng)度)/(外徑*系數(shù)) 二：nd鋼管外徑和承受壓力求壁厚計(jì)算方法：
Method for calculating wall thickness of ND steel pipe by external diameter and bearing pressure: method for calculating external diameter, specification and wall thickness of ND steel pipe to be able to withstand pressure (different tensile strength of different materials of steel pipe) pressure= (wall thickness*2*tensile strength of steel pipe material)/(external diameter*coefficient). 2: method for calculating wall thickness of ND steel pipe by external diameter and bearing pressure:
壁厚=(壓力*外徑*系數(shù))/(2*鋼管材質(zhì)抗拉強(qiáng)度)三：nd鋼管壓力系數(shù)表示方法：
Thickness = (Pressure * Outer Diameter * Coefficient)/(2 * Tensile Strength of Steel Tube Material) 3:nd Pressure Coefficient of Steel Tube:
鋼管壓力P<7Mpa 系數(shù)S=8
Steel pipe pressure P<7Mpa coefficient S=8
7<鋼管壓力P<17.5 系數(shù)S=6
7<Steel Tube Pressure P<17.5 Coefficient S=6
鋼管壓力P>17.5 系數(shù)S=4
Steel pipe pressure P>17.5 coefficient S=4 怎樣判斷nd鋼管的好壞
How to judge the quality of ND steel pipe

首先要看nd鋼管的表面。觀察亮度和表面有無(wú)漏焊和脫皮等表面問(wèn)題。好的nd鋼管表面色澤光亮，一般情況下不會(huì)生銹。
First of all, we should look at the surface of ND steel pipe. Observe the brightness and surface problems such as welding leakage and peeling. A good ND steel pipe has a bright surface and will not rust in general.

第二點(diǎn)就是看材質(zhì)?；瘜W(xué)成分是nd鋼管的基礎(chǔ)。檢查化學(xué)成分是否達(dá)標(biāo)是nd鋼管很重要的檢查方式。還有就是檢查是否精煉爐的材料。
The second point is to look at the material. Chemical composition is the basis of ND steel pipe. Checking whether the chemical composition is up to the standard is an important inspection method for ND steel pipes. The other is to check whether the material of the refining furnace is available.

第三點(diǎn)就是要看做工。圓管的圓度、方管的方度、表面的處理、nd鋼管兩端的處理、還有很重要的一點(diǎn)就是整只鋼管的平直度。
The third point is to look at the workmanship. Roundness of circular pipe, squareness of square pipe, surface treatment, treatment of both ends of ND steel pipe, and a very important point is the flatness of the whole steel pipe.

最后，好的nd鋼管廠家擁有好的管理層、好的操作工、好的制度、有一定的知名度和信譽(yù)度，產(chǎn)出來(lái)的產(chǎn)品自然也能滿足客戶的高端要求。而一些小的或者不正規(guī)的鋼管廠家生產(chǎn)出來(lái)nd鋼管不僅在外觀上與好的nd鋼管有差距，其堅(jiān)硬程度、韌性，也有很大的差距。
Finally, a good ND steel pipe manufacturer has good management, good operators, good system, a certain degree of popularity and credibility, and the products can naturally meet the high-end requirements of customers. And some small or irregular steel pipe manufacturers produced ND steel pipe not only in appearance and good ND steel pipe has a gap, its hardness, toughness, but also a big gap.