Flashcards in Objective 05: Metal Selection for Process Plant Applications Deck (14)
What are the 5 minimum required descriptions that ANSI requires manufacturers to identify pipes, fittings, and flanges with?
2. Wall Thickness
3. Schedule Designation
4. Material Type
5. Manufacturer's Identity Stamp
What measurement does Size refer to when it comes to piping?
NPS in inches or DN in mm
Nominal Pipe Size of the nominal outside pipe diameter or the inside flange diameter
The thickness of piping, steel plate, vessel walls, and pipe fittings, in inches or mm
The thickness of a pipe or fitting based on standard criteria
What does the magnitude of the Schedule number indicate?
The greater the schedule number, the thicker the material, and the greater its ability to withstand internal pressure, corrosion, or erosion
Why can the Schedule number always be known for piping?
It is stenciled along the entire length of pipe, to ensure it can be identified when cut into shorter lengths during construction
What are the 7 ANSI Schedules that are used to refer to the different pressure rating classes of flanges?
What determines the MAWP of a flange?
Class Number and maximum service temperature
What does ASME refer to as Low Temp for piping and fitings?
Limiting design temperature range from -45°C to an upper specified value <425°C
What does ASME refer to as High Temp for piping and fittings?
Limiting design temperature range from -29°C to an upper specified value <425°C
How is piping/fitting lowest temperature service for either the processing fluid or external environment determined?
Charpy Impact Testing that demonstrates that these metals do not become brittle at these temperatures
What are 9 variables that are used to select metal for a pressure piping system?
1. Internal or external maximum pressures
2. Maximum and minimum temperatures
3. Tensile and compressive stress loads
4. Vibration and cyclic stress loads
5. Chemical corrosion exposure
6. Temperature gradients and thermal expansion stress factors
7. Nozzle loading (on flange connections)
8. Impulse stresses (liquid slugging, hydraulic shock, physical collisions)
9. Heat conductivity