Kahhang
Mechanical
- May 4, 2018
- 1
I am currently working on a piping study. The project requires me to design a pipe routing for a high temperature high pressure setting as per ASME B31.1 Power Piping.
In the ASME B31.1 Power Piping Code, there is a clause in page 29 Section 104.8.1 where it shows the requirement that must be met for sustained loads. I have attached the relevant page and formula involved in the attachment below. As seen in the formula, most of the values can be found easily except M(A) which is the moment on cross section due to weight and other sustained loads.
A density of a P91 ASME A335 Steel Alloy material pipe is 7760 kg/m3. According to this density, a 1m pipe would have 2.314kN/m weight acting on the middle of the pipe. According to these values, I found that a simple 2-3 metre pipe will not be able to meet the requirement as set by the ASME code. Logically, I don't think this is the case as I know that a lot of pipes that are longer than 2-3m are already built without supports.
Could someone please explain to me why this is the case? Or am I doing something wrong. One possible resolution that I can think of is that the weight of the pipe itself is not considered as a sustained load in the first place and the sustained load is actually referring to other possible loads instead.
Looking forward to all of your help
Thank you!
In the ASME B31.1 Power Piping Code, there is a clause in page 29 Section 104.8.1 where it shows the requirement that must be met for sustained loads. I have attached the relevant page and formula involved in the attachment below. As seen in the formula, most of the values can be found easily except M(A) which is the moment on cross section due to weight and other sustained loads.
A density of a P91 ASME A335 Steel Alloy material pipe is 7760 kg/m3. According to this density, a 1m pipe would have 2.314kN/m weight acting on the middle of the pipe. According to these values, I found that a simple 2-3 metre pipe will not be able to meet the requirement as set by the ASME code. Logically, I don't think this is the case as I know that a lot of pipes that are longer than 2-3m are already built without supports.
Could someone please explain to me why this is the case? Or am I doing something wrong. One possible resolution that I can think of is that the weight of the pipe itself is not considered as a sustained load in the first place and the sustained load is actually referring to other possible loads instead.
Looking forward to all of your help
Thank you!
