Control Oil

Question 0

What provides cooling water for the control oil hydraulic coolers?

Answer 0

Turbine cooling

Question 1

What is the purpose of the control oil system?

Answer 1

Provides pressurized hydraulic fluid for the operation of:
Main steam CVs
Maintain steam SVs 
CIVs 
EHC system

Question 2

What is the power supply for the main hydraulic pump motors?

Answer 2

NG

Question 3

What is the power supply for the filter pump motor, fans and heaters?

Answer 3

NH

Question 4

What provides power to the EHC control cabinet?

Answer 4

NN

Question 5

What happens to the TC control valves upon loss of IA.

Answer 5

They fail open to the hydraulic oil coolers

The NLO will have to throttle open the bypass around the temp CV and then isolate the CV.

Question 6

What happens to the hydraulic fluid is lost to the CO system?

Answer 6

The turbine will trip

Question 7

What is used to maintain the hydraulic fluid above 85*F?

Answer 7

Two electric heater-fan units.

Automatically operated

Question 8

How is hydraulic fluid maintained at or below 115*F?

Answer 8

The position of the hydraulic fluid coolers cooling water inlet valves is controlled.

Question 9

What pressure is hydraulic fluid provided at?

Answer 9

1600 psig

Question 10

How many hydraulic pumps are there and how many are normally operating?

Answer 10

There are two pumps with one normally in service.

Pump stroke varies to accommodate for pressure demand.

Question 11

What provides cooling and lubrication to the main oil pumps?

Answer 11

There is an auxiliary pump attached to the main pump shaft via chain and sprocket.

Question 12

At what control oil pressure does the standby pump start?

Answer 12

1300 psig

Question 13

Where are the main control oil pumps normally operated from?

Answer 13

Control room.

Question 14

Where are the control oil pumps located?

Answer 14

100’ turbine building

Question 15

How are the four control oil accumulators arranged?

Answer 15

In parallel with a common discharge header.

Question 16

What pressure is the accumulator precharged to with nitrogen?

Answer 16

1000 psig

Question 17

What amount of reserve do the accumulators provide?

Answer 17

200%

Question 18

How many hydraulic fluid coolers are there?

Answer 18

2-100% capacity
In parallel.
One in service one in standby

Question 19

Where are the hydraulic coolers located in the system flow path?

Answer 19

Control oil return line en route to the hydraulic fluid reservoir

Question 20

What cools the hydraulic fluid?

Answer 20

Shell and tube HX

Cooled by TC

Question 21

What removes moisture in the hydraulic fluid reservoir?

Answer 21

Activated alumina

Question 22

What color does the moisture absorbing alumina change to when it is exhausted?

Answer 22

Light pink.

Starts out blue

Question 23

Describe the transfer filter pump

Answer 23

Rotary positive displacement.

Question 24

What provide filtering for the hydraulic control oil when the hydraulic fluid pumps are shutdown?

Answer 24

Fuller earth filters.

Question 25

How is the hydraulic fluid filtering pump operated?

Answer 25

From a local panel START/STOP

Question 26

What is the purpose of the fuller earth filters?

Answer 26

Maintains the oil at a neutral pH and removes chlorine.

Question 27

What prevents the fuller earth filters from over pressurization?

Answer 27

A relief valve set at 75 psig.

Question 28

How does the stealth EHC system function?

Answer 28

It pumps in clean dry air to exclude contaminants and moisture.

Question 29

What is the purpose of the transfer pump filter?

Answer 29

Filter the hydraulic fluid while the reservoir is being filled or drained. Also used under power for continuous filtering. The transfer filter is after the earth filter to remove any fines that may have loosened.

Question 30

What is the purpose of the control oil recirc tank?

Answer 30

Downstream of the transfer filter for batch mode purification. Used during caking

Question 31

What are the four flow path options for valve CO-V204 Transfer and filtering selector valve?

Answer 31

Closed Discharge Recirc to fluid reservoir Discharge to recirc tank.

Question 32

At what pressure does the control oil standby pump auto start?

Answer 32

1300psig

Question 33

How are the hydraulic fluid pumps tested?

Answer 33

HV29 is operated to relieve system pressure. | Auto starts the standby pump.

Question 34

What happens if the control oil pressure drops to 1100 psig?

Answer 34

Alarm in control room and turbine trip

Question 35

What amount of flow is continuously recirculated through the fuller earth filters?

Answer 35

Five percent

Question 36

How would a loss of air effect the EHC fluid reservoir temperature control valves?

Answer 36

They would fail open

Question 37

What would happen to the stealth EHC system on loss of IA?

Answer 37

It would lose its supply air.