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Why does vacuum in steam condenser reduce or drop??

  1-High exhaust temperature: Vacuum drops or maintains at lower side due to high exhaust steam temperature flow into steam condenser. This high exhaust temperature is mainly due to 1-Operation of Turbine at lower loads 2-More clearance in labyrinth seals 3-Not operating exhaust hood sprays 4-More load on condenser 5-Breaking of ejector U loop 2-Low circulating cooling water flow Vacuum in condenser reduces due to inadequate cooling water flow through steam condenser. This is mainly due to; 1-Problems associated with pumps 2-Air pockets in pipe line 3-Leakages in cooling water line 4-Stuck of discharge valve of pump 3-High cooling water temperature at condenser inlet Higher cooling water temperature at condenser inlet results into reduction of vacuum due to poor heat transfer from steam to water 4-Poor heat transfer in condenser Very less or poor heat transfer in steam condenser reduces vacuum to very low level resulting into high exhaust temperature &am

Selected Questions and Answers on Power Plant Safety

1. What is Safety? What are the objectives of safety in power plant?

Safety is defined as freedom from that condition that can cause injury to persons including death or damage to property or environment

Objectives

  •   To create, friendly environment and healthy atmosphere at work.
  •   Prevent accidents and harmful effects on workers’ health
  •   Eliminating injuries to employees and damages to equipments
  •   Provide safety guidelines for appropriate measure of planning control and enforcement.

 2. What is accident?

It is an unexpected or unplanned event which may or may not result in injury or damage or property loss or death.

3. What is an injury ?

It is defined as a harmful condition sustained by the body as a result of an accident.

4. What is hazard?

Inherent property of a substance or an occurrence which has potential to cause loss or damage property, person or environment.

5. What is risk?

In probability of the realization of potential for loss or damage or injury.

6. What is an incident?

It is an event which represents deviation from the intended sequence of designed steps.

7. What is safety policy?

Any company has a social and legal obligation to provide a safe and health working environment to all his improvement to all his employees.

8-What is work permit?

It is the legal written document issued by authorized persons to execute a particular work.

9-What are the different work permits issued in power plants?

A-Electrical related maintenance activities

B-Hot work

C-Height work

D-Confined space work

E-Chemical related works

10-What is LOTO system? & what is its significance?

Lockout & Tag out. It is carried out to isolate equipment from electrical /hydraulic/pneumatic power system to avoid damages to working persons & equipments.

11-What is meant by Job safety Analysis (JSA)?

JSA is the identifying & analyzing the hazardous which are going to be occurred during performing a particular activity.

12-List out the PTW (Permit to Work) steps of Electrical related maintenance works

a-Get the work permit for a particular maintenance work

b-Apply LOTO

c-Issue the Lock out key to working personnel

d-Operate the emergency push button

e-Isolate any other power sources like water, air,  oil etc

f-Complete the work

g-Close the PTW

h-Normalize the equipment for further operation

13-What is hot work? & list out the safe steps of hot work

Any work related to welding, cutting & high temperature fluid related works.

JSA of hot works.

A-Welding & cutting

a-Get the work permit

b-Identify the competent person for a particular work  eg. Welder/Mech.technician

c-Ensure all the PPEs are available with working person

d-Ensure all combustible materials like, fuel, lubricant etc have been isolated from working area

e-Ensure water hose pipe, sand buckets   are made available for immediate use.

f-Perform the work

g-Close the permit.

h-Normalize the equipment or system.

B-Steam line related work.

a-Get the work permit.

b-Identify the competent person.

c- Ensure all related  the PPEs are available with working person.

d-Isolate particular line by opening/closing the valve

e-Perform the work

F-Close the work permit

g-Normalize the system..

14-List out the hazardous during welding

1-Burn injury

2-Electric shock

3-Poisonous fumes

4-Sparking noise

5-Fire explosions

3-Radiation heat

 15-What is height work & list out the safe steps of height work?

Any work which is at a height of more than  1.8 m from ground level. Work at height means work in any place where, if precautions were not taken, a person could fall a distance liable to cause personal injury

18-What is meant by confined space?

An area which is small and enclosed or an area where one entry and exits or where a man cannot work comfortable in any location is caused confined space.

OR

In order for a work area to be defined as a confined space it must meet all three of the following criteria

1-Limited openings for entry and exit

2-The space is not intended for continuous human occupancy

3- The space is large enough for you to enter and conduct work

According to OSHA, if a space does not meet all three of the above criteria, it is not considered as confined space

19-Givesome examples of confined space?

Pipes, vessels, tanks, Boilers, Silos, trenches & excavation deeper than 4 feet.

20-Name the hazardous jobs in confined space.

Welding, grinding & use of chemicals.

 21-Define near miss

It is an unplanned event that has the potential to cause, but does not actually result in human injury, environmental or equipment damage, or an interruption to normal operation.

22-Classify the fires & extinguishers

Sl No.

Fire class

Extinguisher type

Application

1

A

Water

Flammable solids, such as wood, paper, and fabric

2

B

Foam

Turpentine, paint, petrol etc

3

C

Dry powder

Flammable gases

4

D

Co2

Combustible metals like magnesium, aluminum

5

F

Wet chemical

Cooking oil

 23-What are the duties of a safety officer?

1-Tool box talk preparation

2-Monthly statistics preparation

3-Near miss recording & preventive action schedule

4-Preparation of accidents reports

5-Safety meeting & training arrangements

6-Inplant training of fire extinguishers & firefighting system

7-Arranging safety competitions like quiz, slogans, poster exhibition etc

8-Maintaning first aid box at all various areas of plant.

24-What is meant by lifting plan is?

Is the documents prepare for planning a critical lift by calculating and considering all factors which is going to effect the lift and thereby selecting the correct tools & cranes and ensure the safe lifting procedure to be followed for the particular lift.

25-What is SWL?

Safe working load is the maximum load that can be applied to the lifting tool, safely.

26-What is Tandem lift?

A lift in which two cranes are used for lifting.

27-What is trench?

A narrow excavation, where the depth is greater than width.

28-What is toe board?

Barrier secured along the sides and ends of a platform to guard falling of materials, tools & other objects.

29-What is the minimum height of toe board?

4”/100mm

30-What is the height of the top rail from the platform?

38 to 45 inches

31-What is the minimum width required for walkway?

18 inches

32-In what circumstances fall protection system has to be used?

If the person could fall more than 1.8m height.

33-Commonly used abbreviation used in safety

OSHA: Occupational Safety and Health Administration

OHSAS: Occupational Safety and Health Assessment series.

SWL: Safe Working Load

LTI: Lost Time Incident/Injury

LMI:Load Movement Indicator

MSDS:Material Safety Data Sheet.

ERP:Emergency Response Plan

JSA:Job Safety Analysis

UEL:Upper Explosive Limit

LEL:Lower Explosive Limit

SCBA:Self Contained Breathing Apparatus

RSO: Radiation Safety Officer

HIRA:Hazard Identification & Risk Analysis

TBT:Tool Box Talk

SOP: Safe/Standard Operating Procedure

SMP: Safe or Standard Maintenance Procedure

34-What is Hydro-test?

It is the test carried out for leak test for pipes, vessels, by filling water  with some designed pressure.

35-What is Hypot- test?

It is the insulation leakage test done for high voltage electrical cables

36. What is safety tag?

Safety tag can be defined a surface made of card board or paper board on which English local languages letters written for warning safety instructions to employees.

38. What are belongs to un hygienic working environment?

Presence of toxic, High temp. Excessive noise Emission of radiation improper lighting improper ventilation Process involving handling of poisonous.

39. What is ingestion?

Entry of harmful materials through mouth is called ingestion.

40. What is inhalation?

Entry of harm full materials through mouth is called ingestion

41. What is delegated work permit?

Delegated work permit used for areas requiring light control. Ex : Fabrication, yards – valid – 30 days

42. What is blanket permit?

A blanket permit is a permit issued on the basis of location where the multiple jobs are to be carried out at safe location.

43. What is first aid?

Firs aid is temporary and immediate care given to the victim of an accident.


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