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ＮＰＴ与ＮＰＳ的螺纹有何区别？

请问张老师，ＮＰＴ与ＮＰＳ的螺纹有何区别？
L]?)`!d5I 谢谢！

ＮＰＴ与ＮＰＳ的螺纹有何区别？

[quote][b]下面引用由[u]claire74[/u]在 [i]2006/03/11 08:32pm[/i] 发表的内容：[/b]
8eD'_Q*e D)c1K 请问张老师，ＮＰＴ与ＮＰＳ的螺纹有何区别？
|,b Rtyb5L~ 谢谢！
Yzr)K~%@I*x vb8Y [/quote]!{G"\k{ A_"B

/z4ACU{!US:R2l National pipe thread (NPT) is a U.S. standard for tapered threads, originally used to join steel or brass pipe and fittings. The 1/8 inch, 1/4 in, 3/8 in, 1/2 in, 3/4 in, 1 in, 1 1/4 in, 1 1/2 in, and 2 in sizes are commonly used, appearing on pipe and fittings by most U.S. suppliers. Smaller sizes than those listed are occasionally used for compressed air. Larger sizes are used less frequently because other methods of joining are more practical at 3 inch and above in most applications.
5e2B,v2xH~#Ba Nominal Pipe Size (NPS) is loosely related to the inside diameter of schedule 40 pipe. Because of the pipe wall thickness, the actual diameter of the threads is larger than the NPS, considerably so for small NPS. Other schedules of pipe have different wall thickness but the OD and thread profile remain the same, so the inside diameter of the pipe is therefore different than nominal.G |&S.P5Q+j Xu
Threaded pipes can provide an effective seal for pipes transporting liquids, gases, steam, and hydraulic fluid. These threads are now used in materials other than steel and brass, including PVC, nylon, bronze and cast iron._A vl$x4z/e
The taper on NPT threads allows them to self-tap slightly when torqued and form a seal as the threads compress against each other, as opposed to straight thread fittings or compression fittings in which the threads merely hold the pieces together and do not provide the seal. This means that NPT fittings are easiest to make leak free with the aid of Teflon tape or a similar thread sealant compound. It also means that NPT fittings should only be assembled and disassembled a limited number of times, because the deformation of the threads will result in a poorer quality seal over time.
-p"~Zl y!C\B There is also a semi-compatible variant called NPTF or Dryseal, designed to provide a more leak-free seal without the use of teflon tape or other sealant compound.,H)vjMjx%S/e1aI7_,Fa
Sometimes NPT threads are referred to as MPT or FPT, for male (external) or female (internal) threads, respectively.1Q;O [M9h'E

ＮＰＴ与ＮＰＳ的螺纹有何区别？

got it .thank you so much.
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