IT IS THE ALLAH WHO SUBJECTED THE SEA TO YOU.THAT SHIP MAY SAIL THROUGH IT BY HIS COMMAND ,THAT

YE MAY SEEK OF HIS BOUNTY,AND THAT YE MAY BE GRATEFUL

(Al-Quran)

Marine Engineering

Pumps

Pumps

• There are two types of pumps mainly– Nonpositive displacement(dynamic)

• Centrifugal pump• Axial pump

– Positive displacement• Rotary

– Multirotor– Single rotor

• Reciprocating – Diaphragm– Piston/plunger

Centrifugal pumps

– These are nonpositive displacement pump – These are categories non-positive because if

the discharge is closed; and pump is running no effect on the pump as well as on the pipeline

– Different cofiguration of these pumps are• Vertical

– Two stages (higher discharge usually)– Double suction and single discharge(low disc. Usually)– Doubleeeee

• Horizontal

Centrifugal pumpsVertical

Two stages (higher discharge usually)

• Two stages give good higher discharge

• It is used as Fire and General service pump

• Abbrevation used in ship is F&GS P/P

Centrifugal pumpsVertical

Double suction and single discharge(low disc. Usually low npdh)

• This pump have good suction and discharge pressure is not so much higher than previous pump

• This pump is used as Ballast p/p

Centrifugal pumpsVertical

Two stages (higher discharge usually)

• Two stages give good higher discharge

• It is used as main sea water pump

• Abbrevation used in ship is MSW p/p

• Difference between this pump and the pump in slide #07 is that it is provided with bush instead of bearing.

Centrifugal pumpsHorizontal

Two stages (higher discharge usually)

• Two stages give good higher discharge

• It is used as boiler circulating pump

• Abbrevation used in ship is BLR CIRC. P/P

• The impeller used in this boiler made up of steel because of higher temperature.

Pump parts• Fire and gs pump• Parts of pumps • body (CI)• impeller (brass) 2no.• bearing (ball) 1no.• center bush (brass) 1no.• h-ring (brass) 2no.• end bush (brass) 2no.• wear rings (brass) 2no. with steel hollow lock pin• mostly this pump faces the end bush problem• Ballast pump • body (CI)• wear ring (steel) 2no.• o-ring (to separate) 2no.• impeller (brass) (double suction single discharge) 1no.• main problem is wear ring problem• boiler feed pump • body (CI)

Pump parts(contd)

• wear ring (brass) 2no.• center bush ( brass) 1no.• h.ring (brass)(with hole for cooling) 2no.• gland (brass) 2no.• bearing (……….)(ball bearing ) 2no.• locking pin (steel)(to place the wear ring at its position)• non ZZ if grease nipple is available(otherwise ZZ)• main problem• non ZZ if grease nipple is available(otherwise ZZ)

Pump parts(contd)

• bearing problem(humming sound )• gland packing leakage• 3 will damage the bearing• if wear ring cut out it will disturb the suction and

discharge pressure.• During watch we check the following parameter• open the particular valve suc and dis for particular pump• switch on the motor • check the suc and discharge• check for any leakage • check the movement of fluid by touch hand with

discharge pipe.

MT Quetta• MT Quetta• Crude oil pump turbine (centrifugal pump)• Rpm 1200/1200• Upper bearing 50• Lower bearing 71• LO in 52/55• LO out 44/50• Gland steam 1MPa• Exhaust steam 0.04 MPa/0.03 MPa• Lub oil 0.12MPa/0.12 MPa • Suction 0.01MPa / 0.02MPa• Discharge 0.6MPa/0.7MPa• Steam Chest 0.7MPa• Ballast pump (1S)• Suction : -0.1MPa• Discharge: 0.25MPa• P/P casing: 29• Upperside P/P brg 40• Lowerside P/P brg 46• Bulkhead Stuffing box• The difference between mt johar and mt quetta boiler and economizer is that ……..• In the johar the economizer getting the feed from the steam accumulator and the quetta getting the feed from the

aux. boiler water drum.

Domestic fridge and Air conditioning

• Today I am describing about the domestic refrigeration(DOM Fridge) and as well as air conditioning plant (A/C acc.)of tanker ship MT Johar.

• The parts which are I have seen in the refrigeration plant are:• Compressor• Condenser• Thermostatic expansion valve• Evaporator• And other auxiliary components are• Thermostat (operated on principal of expansion/contract : used to set the conditioning

temperature)• Sight glass• Oil separator• dryer• We can divide the fridge or A/C system into • Low pressure• High pressure • You can seen the block diagram for A/C system.• The compressor we used on the board ship may be of y or w type

Author Introduction

ZEESHAN AHMED, Marine Engineer. After doing FSc(pre-engineering) from PAF(fazaia) intermediate college Lahore cantt. I joined Pakistan Marine Academy and choose Marine engineering branch. Two years of training at academy (practical + theoretical) we learned a lot of thing like CNC (computerize numeric code), trained on various models (like control valve, solenoid valve, flow meter, refrigeration system,

CPP propeller, Main engine model (TWO stroke), Boiler model (water tube) ……………………………….. in GEK (general engineering knowledge) lab, Mechanical and physics lab, Engineering workshop. ETC . After two years, we joined PNSC workshop for the training of ONE year Industrial training. That was also the golden time where we learnt a lot of things at different shops as well as onboard (repairing and watch keeping). I learn many thing on tanker E.g. MT Johar (learn how to dismantle turbine rotor from casing and what are the precautionary measurement while working on turbine, learn how to change the diaphragm(stationary blade) Plate type heat exchanger gasket change, shell and tube Cooler Anode replacement and (Cont.)

Introduction (cont.)cleaning of SALT WATER tubes etc.) , MT Swat (major thing which I learn in Swat is how to dismantle head of main unit and copper gasket replacement with a minor facing defect which is found during overhauling which is filled and faced by Belzona) , MT Lahore(About the DEAD MAN ALARM, Alpha lubricator for Cylinder Main Engine Unit, Pump operation and watch keeping), MT Quetta(Auto load sharing of Generator Set, MT Karachi (Dry washing of the main engine turbocharger with granules, water washing of IG Fan of Inert Gas system, sludge removal of from purifier(centrifuge) etc., . One thing I want to added is that the trend in ship building is more toward based on electronic and electrical application. So a marine engineer must strong in automation, instrumentation and control system. PLC (programmable and logic control) and SCADA (supervisory central access and data acquisition) are the upcoming technology that are using on modern ship. The latest engine of MAN B&W is based on Camless technology. Chain is removed ; fuel pump and exhaust valve actuation is control by hydraulic servo(lub) oil which is driven by Axial piston pump mounted on the Fly wheel.

Regards,

Z.A.

Author contact information

• zeetec4@yahoo/gmail/hotmail.com

Social networking sites.• Facebook: mariner46

Website: zeetec4.googlepages.com

Any question and suggestion are welcome