What is Super Piping? ASME B&PV Code Section III Subsection NB

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SUMMARY

The term "super piping" refers to the section of pipe from the steam generator to the containment isolation valve, characterized by multiple penetrations for safety and relief valves. This terminology is not widely recognized but is discussed in the context of ASME B&PV Code Section III, Subsection NB, which governs Class 1 piping construction. The design of this piping is reinforced to handle full primary pressure, typically between 1000 to 1200 psi, and is crucial for safety during scenarios like steam generator tube ruptures (SGTR). The pipe's design ensures that pressure does not exceed approximately 7.5 MPa due to safety valves.

PREREQUISITES
  • Understanding of ASME B&PV Code Section III, Subsection NB
  • Knowledge of Class 1 and Class 2 piping classifications
  • Familiarity with steam generator tube rupture (SGTR) scenarios
  • Basic principles of pressure safety systems in nuclear engineering
NEXT STEPS
  • Research the specifics of ASME B&PV Code Section III, Subsection NB
  • Study the design and safety features of Class 1 piping
  • Learn about steam generator tube rupture (SGTR) mitigation strategies
  • Examine the role of safety valves in pressure control systems
USEFUL FOR

Nuclear engineers, safety analysts, and professionals involved in the design and maintenance of piping systems in nuclear power plants will benefit from this discussion.

Muti
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The pipe portion from top of steam generator up to containment isolation valve once I heard is called super piping due to number of penetrations in the pipe for safety and relief valves. Is this term correct? Class 1 piping are constructed according to ASME B&PV code section iii, subsection NB. Can I found such terminology (and rules for construction) in subsection NB or somewhere else (if this terminology exist)?
 
I have heard the pipe run between the containment penetration and the main steam isolation valves called super pipe. My understanding was the pipe material certs and fabrication procedures and inspections were such that a pipe break need not be postulated in the section of pipe. I'm not real sure about this though. It seems to me that you could have a break downstream of the MSIV, with failure of MSIV to close as a single failure, and have the same effects as a break in the super pipe. So, what's the point of the super pipe? dynamic effects in the safety valve / MSIV room??

Maybe get more answers in the nuclear engineering section?
 
Thanks gmax so now I know at least this word is said sometimes but not a popular term. From you description it come to my mind piping from SG to MSIV is usually design for full primary pressure because of SGTR. May be due to this connection the pipe length you described might be called super pipe.
 
No, the steam piping design pressure matches the design of the SG secondary, typically 1000 to 1200 psi, depending on the plant.
 
gmax137 said:
No, the steam piping design pressure matches the design of the SG secondary, typically 1000 to 1200 psi, depending on the plant.
Thanks gmax, you are right. The pipe portion between containment penetration and MSIV is thickened and reinforced in design. Pipe portion up to MSIV is Class 2, while rest is non safety class.I was wrong in previous post because I forgot safety valves in SGTR case. Due to safety valves steam line pressure can not rise above design pressure of about 7.5 MPa.
 
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