Installing and tightening tie rod of main engine on ship

Installing and tightening of tie rod after taking it out

1)clean the thread and try the nuts, ease up is required. Check landing area,square up is required.
2) Apply grease lubricants to the threads and landing
3)Insert tie rod.

4)Now tighten the tie rods bolts , tighten the lower nuts first and then the upper nuts, by hand using a spanner.
5)Now install hydraulic tool across a pair of tie bolts. Always a pair of tie bolts should be tightened at a time.
6)Tighten the tie bolts as per maker instruction as regards to tightening stages,, sequence, hydraulic pressure, checking of strech.

7)Check with thin feeler guage to ensure that there is no clearance at the nuts or landing tools.
8) Remove hydraulic tool, apply the thread protective cap.
9) Tighten the intermediate clamping or pinching screws.

Different types of valve in ship and it's uses;
GLOBE VALVE
There 2types of Globe valve used;
1) RETURN TYPE GLOBE VALVE
a)straight through and angle globe valve.

  USES-
# Mainly used in LO and FO filling,transfer and purifying system (eg Suction side of  fuel oil transfer pump, suction side of purifier supply pump, filling and suction valve of HFO bunker tank) .
#In the boiler feed water system.
#control air system
#steam service system(no non return valve here)
#compressed air service system

2)NON RETURN TYPE GLOBE VALVE
a) straight through and angle non return valve

- It's uses are very less eg before the 3way valve of the purifier inlet.
b) screw down non return valve(SNDR)-

USES -
#discharge side of HFO transfer pump and purifier supply pump.
#boiler feed water check valve.
# fire and bilge pump discharge valve
#suction valve of bilge well
#suction and discharge valve of bilge transfer pump and bilge seperator pump.
#emergency bilge suction
# discharge of air compressor and air bottle
# steam condensate system all drain
#F.W service system.
#ME LO pump dischage valve


BUTTERFLY VALVE
There are various type of butterfly valve they are;
a)wafer lever type
b)lug lever type

c)wafer gearbox type.
d)lug gearbox type

USES OF 
wafer and lug type butterfly valve are used in
#In all sea water pipeline valve. Cooling sea water pump suction and discharge valve.
# suction valve for fire and bilge pump from bilges and cargo hold bilges.
#In LOW temperature cooling water system . LT WATER inlet and outlet to air cooler,LO cooler etc
#HT cooling system. In HT cooler both inlet and outlet valve for LT and jacket water.
#No butterfly valve is used in FO and LO system.
#FWG suction and discharge valve.

e)butterfly check valve.
Butterfly check valve are basically non return valve used in;

#Cooling sea water pump discharge has both lug gear type butterfly valve and butterfly check valve.
#same as for FWG ejector pump discharge has both lug gear type and butterfly check valve.


GATE VALVE

THE GATE VALVE USES IS VERY LESS you can find it in few places like furnace drain valve in boiler.

SAFETY VALVE

There are basically 3types of globe or straight through type safety valve
1)ordinary safety valve
2)high lift safety valve
3) improved high lift safety valve

USES
# IN every  PLATE TYPE HEAT EXCHANGER of Lube oil and Fuel oil.
#AIR BOTTLE
#BOILER
# After the FO supply pump in FO service system of main engine.etc

RELIEF VALVE

The relief valve can be straight through and angle type.

USES
#SCAVENGE AIR RECIEVER
#In all GEAR TYPE OF PUMP(ex FO supply , FO circulating, FO transfer pump etc)
#After every stage of air compressor
#In cylinder cover
# In discharge side of refrigerant compressor and also fitted in the condenser


QUICK CLOSING VALVE

USES
# Suction of HFO service and settling tank to purifier.
#Suction of bunker tank to settling tank
#suction of waste oil service tank to incinerator.
#Suction of generator engine LO settling and service tank
#suction of main engine LO settling and LO service tank.
#Suction of CYLINDER OIL storage tank.

The various valve symbol

Construction and installing Mechanical seal on centrifugal pump on ship

Mechanical seal is a sealing fitted on the shaft of the centrifugal pump to prevent fluid leakage from the pump impeller. Mechanical seal act as a check valve and a slider bearing. The obvious function of check valve is to prevent liquid under pressure from leakage out of the pump or from drawing air into the pump ,when under a vaccum condition.

--Mechanical seal is pressed up in the top of the impeller vane and fitted to the pump shaft by circlip.
--It has many part Rotary seal and stationary seal. The rotary seal has a spring.

--The rotary part of a seal has a ceramic porcelain or carbide material.
-stationary part seal are made of highly finished carbon and rest on mechanical seal cover while is bolted to pump casing and this seal does not rotate. The stationary seal ring are brittle and can be easily chipped or damaged so it should be handled with care.
- Spring in the rotary. seal is there to compensate for microwear down of the rotary part carbon surface and rotary part carbon material.
- The o-ring is there in both stationary and rotary seal and are made up of rubber like substances called an elostomers. This type of elostomers material is selected to match the temperature limit and types of material being pumped. Should the temperature limits exceeds o-ring becomes hard and cracks sometimes.

MECHANICAL SEAL INSTALLATION
1) check the rotary full length and marking note down.
2)Mark where to put stationary and rotary to shaft and fit it.

MECHANICAL SEAL LEAKAGE
1)Incorrect type of mechanical seal
2)Bent shaft
3) mechanical seal improperly installed
4) O-ring damaged
5)mechanical seal runs dry can cause the faces to become hot without lubrication and the carbon faces can turn to a dull black powder.

DAMAGE TO MECHANICAL SEAL
1) due to abrasive particle in the liquid being pump(ex.mud in sea water)  infiltrates with the liquid between the seal faces and grind away the carbon priming rings.
2) heat damage- excessive heat can damage primary ring and the elastomer parts.

Priming of a fuel line filter on ship

Air often gets into the fuel line because of cleaning the filter or any maintenance. This causes the engine to have problems in starting and also air can cause corrosion of the filter element. 
So in Marine fuel filter during changeover of filter or  putting back the filter after cleaning, priming is done in order to remove air from the system.
The procedure after cleaning the filter and putting back.
1)put the filter after cleaning
2) open the purge cock and open the fuel oil suction valve. Now air will come out of the the purge line. Close the purge valve once only oil flows through the line.
3)now the filter is in operation. 

Safety fitting on bunker lines on ships

1) The high level alarms with visual and audible in case ol is fully filled in bunkers tanks.
2)overflow sight glass ,it is there in bottom platform just before the overflow tank to visually check if the bunker tank is overflowing.
3)Quick closing valve in all bunker tanks . They should be closed quickly from remote places .
4)Relief valve in bunker lines if suppose pressure in the line increases it will lead to overflow tank.
5)Drip tray below the flange, if suppose there is a leakage from the flange.
6)pressure gauge in the bunker line should be checked during bunkering . Ensure the line pressure does not exceed the maximum working pressure.

Characteristics of shipboard bilge line valves

The characteristics of shipboard bilge lines valves are as follows;

1) From the bilge well suction , the valve is generally screw down non return type.It is there to prevent flooding back of bilge well.
2)Discharge from the fire and bilge pump is screw down non return valve.
3) At the suction of the fire and bilge pump the ,the bilge valve must be of screw down non return type to prevent water from entering the bilge line from the sea chest or ballast suction.
4) material which can be used is generally steel, it required protection inside and out and both surfaces should be galvanized.