SPED Equipment Piping (Pumps, Exchangers, Vessels & Control Stations)

Question 1

On a horizontal pump suction line where a reducer is needed, how should an eccentric reducer normally be installed?

Accepted Answer

Flat side on top

Answer

With the flat side up (top flat), there is no high point where vapor or air can collect at the pump inlet. A trapped pocket could cause cavitation or vapor lock.

Question 2

For a centrifugal pump to operate without cavitation, which condition must be met?

Accepted Answer

NPSH available must exceed NPSH required (with margin)

Answer

The system's NPSHa must exceed the pump's NPSHr, usually with a safety margin. Otherwise the liquid flashes to vapor at the impeller eye and causes cavitation damage.

Question 3

On a centrifugal pump discharge, where is the check valve normally located?

Accepted Answer

Between the pump discharge nozzle and the discharge block valve

Answer

The check valve goes between the pump and the discharge block (isolation) valve. When the block valve is closed, the check valve can be isolated and maintained, and it prevents backflow into the pump.

Question 4

A typical control valve station (manifold) consists of:

Accepted Answer

The control valve with upstream and downstream block valves plus a bypass line with a globe valve

Answer

Block valves on both sides let the control valve be isolated and removed. A bypass with a throttling valve (typically a globe valve) lets operators control the process manually during maintenance. Drains and vents are usually included.

Question 5

When routing piping around a shell-and-tube heat exchanger with a removable bundle, the designer must:

Accepted Answer

Keep a clear area at the channel end at least equal to the tube bundle length for bundle pulling

Answer

A removable bundle is pulled out from the channel end, so that area must stay free of piping and structures for at least the bundle length. Channel-head piping is usually flanged so it can be removed.

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

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

SPED Equipment Piping (Pumps, Exchangers, Vessels & Control Stations)