2) Piping Interview Questionnaire

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MILIND SATPUTE PIPING GUIDE

PIPING INTERVIEW QUESTIONNAIRE

PUMPS

1 What is NPSH ?An s : It is measure of the pressure drop of the liquid as it moves formthe inlet of the pump to the eye of the impeller, determined by testingand expressed in feet of water by pump manufacturer.

2 What is cavitation ?An s : Cavitation is a rapid collapse of vapor pressure that can producenoise, result in loss of head and capacity and create a severe erosion ofthe impeller and casing surface in the adjacent inlet areas.

3 What is velocity head?An s : The head loss caused by the consumed power to acceleratestationary fluid to suction line velocity during pump startup. Its about 1 ft.

4 What is standard for petroleum pumps?An s : API 610 is the standard for centrifugal pumps in petroleumindustry.

5 Where positive displacement pumps are used ?An s : Used to move viscous liquids, injects chemicals or additives into a

system, or pump quantities too small for centrifugal pumps.

6 What are types of rotary pumps ?An s : External Gear, Cam and piston, two lobe, three lobw, single screw,Two screw.

7 Where rotary pumps are used ?An s : For viscous liquids that are free of hard and abrasive fluids.

8 Where should boiler feed water pumps be located ?An s : They take water from a deaerator and generally operate close tothe vapor pressure of the liquid, hence they must be located as close tothe deaerator as possible.

9 Tell something about vertical pumps ?An s : Used where low available NPSH is not sufficient, for surfacecondenser, for waste material in concrete pit, screen at the bottom.

10 Where centrifugal pumps in vacuum service be located ?An s : directly below tower, may be on spring supports.

11 How to support discharge line of centrifugal pump ?An s : Discharge line should be supported as close to the top elbow as possibleand should be within five diameters of that elbow, using spring support.


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1 Where spiral heat exchangers are used? An s : Generally in chemicalplants2 How piping is positioned for spiral heat exchanters ? An s : Pipingpositioned to allow opening of covers and the removal plates.

SHELL AND TUBE HEAT EXCHANGERS

1 What are the types of tube arrangments?An s : U-tube, Fixed tube, kettle arrangement.

2 What is full form of TEMA?An s : Tubular exchangers manufacturers Association.

3 Which fluids to be sent through tubes?An s : Fouling and/or corrosive fluids (Easy cleaning and cheaper toreplace tubes than shell), hotter fluid : To reduce heat loss to thesurroundings except steam., refrigerant, cooling fluid.

4 What should be clearance between flanges of exchangers?An s : 1000 MM.

PLATE EXCHAN GERS

27. Where plate exchangers are used ?

An s : Low pressure, low temperature applications.

DOUBLE PI PE OR FI N TUBE EXCHA NGERS

28. Where used ?An s : Used when liquid has a greater resistance to heat flow than anotheror when the surface area is small.

AI R COOLER EXCHA NGERS

29. Where used ?An s : To cool tower overhead vapors.


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LPG STORAGE

1 How to group LPG Vessels ?An s : Max 6 Vessels, total capacity 15,000 cum, curb wall, distancebetween vessels of different groups 30M, separate dedicated manifold for

each group.

2 Where to located LPG Storage ?An s : Downwind of process units, important buildings and facilities, not insame dyke where other flammable liquid HCs stored, single row in caseof spheres and bullets, not one above the other, bullet head not towardother vessel, no dip ditch to avoid LPG Settling.

3 How to operate LPG Cylinders ?An s : Separate area for empty and filled cylinders, Cylinders vertical, not

near other gase cylinders, never below grade, smooth trucking traffic.

Documents

2) Piping Interview Questionnaire