3 replies to this topic

[ayan_dg]

I have a 4 inch pipe with schedule 40 and another with schedule 80 when should I use Schedule 40 & when should I use schedule 80 ?

I can reframe the question is another way , What is the use of having so many schedules for the same pipe size ?

[Art Montemayor]

Ayan:

You are spending too much time on theory. Get practical. What are you going to do when you have two fluid streams - one at 100 psig and another at 1,000 psig. Do you think that you would put them into the same pipe rating? Would you put them in Schedule 40 pipe or in Schedule 80 pipe?

Download my workbook on the Crane Tech Paper #410 and read about pipe schedules and what they mean. I try to explain what a pipe schedule is and what it is used for and I did it because I got tired a long time ago of explaining the same thing to green engineers time-after-time. This is an important topic. Don't take it lightly or it will come back to haunt you when you are least prepared to deal with it.

[viral desai]

Let me explain to you in LAYMAN's language. Sch 80 pipe will have higher thickness than sch 40 pipe. So it will withstand more internal pressure. By definition, Schdule is = 100 P/S.

where P is internal pressure and S is maximum allowable stress at given temp.

[Technocrat]

Hi Viral,

Schdule no. is = 1000 P/S,

Regards.