SPED Valve & Fitting Selection 3

Question 1

In ASME B16.5, what does the Class 300 pressure-temperature rating for a carbon steel flange signify?

Accepted Answer

A pressure-temperature rating group that varies with temperature

Answer

ASME B16.5 Class designations represent rating groups where the maximum allowable working pressure decreases as temperature increases, following published tables.

Question 2

Which type of valve disc design in a butterfly valve provides improved sealing performance at high differential pressures?

Accepted Answer

Triple-offset disc

Answer

Triple-offset butterfly valves use a conical seat geometry that produces zero friction during opening/closing, enabling tight metal-to-metal shutoff at high pressures.

Question 3

A fitting used to connect two pipes of different schedules (wall thicknesses) with the same nominal pipe size is called a:

Accepted Answer

Swage nipple

Answer

Swage nipples transition between different pipe schedules while maintaining the same nominal diameter, providing a smooth bore transition.

Question 4

For a valve in chlorine gas service, which packing material should be avoided due to attack by wet chlorine?

Accepted Answer

Neoprene elastomer

Answer

Neoprene (polychloroprene) and most elastomers are attacked by dry or wet chlorine gas, making PTFE or graphite-based packings the correct choice.

Question 5

What is the purpose of a spectacle blind (figure-8 blind) in a piping system?

Accepted Answer

To provide visual confirmation of isolation or flow status between equipment

Answer

A spectacle blind provides a permanent, positively isolating blind or spacer that can be flipped, with the open or blind position visually verifiable at the flange.

(SPED) Society of Piping Engineers and Designers Certification Practice Test

(SPED) Society of Piping Engineers and Designers Certification Practice Test

SPED Valve & Fitting Selection 3