Question 1

How to blow down the boiler?

Accepted Answer

Blow down to dump sludge, scum and dissolved solids: scum off the top, solids off the bottom, ship-side valve first and water level never lost. Purposes: remove solids, dirt, foam and oil from boiler water and hold density down. Two routes: scum blowdown skims the surface layer; bottom blowdown dumps settled impurities. Three depths: flash blowdown for settled sludge, partial blowdown to the gauge-glass bottom level when chlorides, phosphates or alkalinity run high, complete blowdown only for survey or maintenance. Sequence for full/partial: kill fires, shut steam stops, let pressure fall to about 5 bar, open scum cock first, then the shipside valve — open overboard side first and close it last so the boiler valve never takes the full differential alone. Surveyor follow-up: chlorides just failed high — flash, partial or complete blowdown, and how do you confirm the result?

Question 2

Cylinder head pressure testing

Accepted Answer

Pressure-test the head to prove the water jacket: clean it, close it up, hold hydraulic pressure and read for weeps and cracks. Strip carbon, descale the water jacket and check for scaling and corrosion before any test. Blank openings and apply hydraulic pressure — about 7 bar on the jacket — holding and watching for weeps, seeps and pressure fall. Dye-penetrant backs the test on suspect faces; valve seats get checked for acid corrosion, bending and blow-by at the same opening. Springs, valves and seats renewed on condition — a head that will not hold pressure never goes back on. Surveyor follow-up: pressure holds but one valve seat weeps water — head, seat or valve, and what proves it?

Question 3

what overhauling u have done onboard ??

Accepted Answer

Answer overhauls as job cards: what, why, readings, parts and tests — surveyors promote stories with numbers. Name the machine and the trigger: hours, survey, breakdown or parameter drift. Quote readings before and after — clearances, pressures, temperatures and timing. List parts renewed, clearances set and torques used, with maker limits beside each. Close with tests run and results: trial readings, alarms proved and log entries made. Surveyor follow-up: pick your biggest overhaul and give me three numbers from it.

Question 4

gauge glass blowdown

Accepted Answer

Blow the glass to prove both legs: steam jet first, water jet second, then refill and watch the level settle true. Shut steam and water cocks, open the drain, then crack steam — a strong jet proves the steam leg clear. Shut steam, open water — a strong jet proves the water leg clear. Shut water and drain, reopen water so the glass fills high, then open steam and let the level settle. No water after blowing means no water in the boiler: shut down at once, ease pressure, never feed a hot empty boiler. Surveyor follow-up: level sits high and lazy after blow-through — which leg is choked?

Question 5

Since corrosion may happen on the part above the upper bearing

Accepted Answer

The shaft above the top bush corrodes where seals weep and air meets oil: bronze liners, glands and drains guard it. Shrunk bronze liners with rubber seals stand between steel shaft and seawater at the sternbush. Worn bearings vibrate and whirl, rewooded late with sediment and damaged propellers shortening life to months. Radial face seals back the liner with drain cocks proving leaks — water out means seals failing inward. Pressurise past outside head on light drafts to watch for oil globes betraying the outer seal. Surveyor follow-up: drain cock runs water with oil pressure normal — seals, liner or bearing, and what first?

Question 6

Enumerate at least five common faults in welding and measures to prevent. Substantiate your answer with suitable sketches

Accepted Answer

Sketch five faults with cures: undercut, slag, no penetration, porosity and cracks — current, cleaning and groove decide. Undercut from hot current and long arc — cut amps, shorten arc, steady travel with sketched groove edge. Slag trapped between passes from dirty beads — clean every bead before the next with sketched inclusion. No penetration at the root from tight groove — open root gap and prove fusion with sketched section. Porosity and cracks from damp rods and dirty plate — dry rods, clean steel, controlled heat with sketched pores. Prevent by procedure, prove by visual, dye, ultrasonic and X-ray in that order. Surveyor follow-up: draw the undercut section — where does the notch sit, and what current change cures it?

Question 7

Purifier manual desludging procedure?

Accepted Answer

Manual desludge stops, displaces and opens: displace oil to service, drop the slide, sling sludge, reclose and restart by the book. Displace purified oil to the service tank with water, then stop closing water and pulse opening water to drop the slide. Sludge ports open as the bowl drops — sludge flung outward to the sludge outlet for the timed seconds. Re-admit lifting water to reseal the bowl edge, then water and oil in sequence to restart purification. Self-cleaners desludge running; manual bowls stop, brake past critical speed, open, clean the sludge space and rebuild. Surveyor follow-up: oil to the sludge tank after desludge — bowl height, seal ring or timing, and what proves it?

Question 8

How to purge air from refrigeration system?

Accepted Answer

Purge air at the condenser after proving sub-cooling: pump down, compare pressure to saturation, vent the top. Air shows as high condenser and discharge pressure with bubbles in the glass, hot running and swinging gauges. Prove by liquid pressure-temperature against the saturation chart with cooling water trimmed to near-saturated. Pump down to the condenser with the outlet shut, then crack the purge valve until pressures settle. Find the entry — shaft seals, hoses or long vacuum-side standstill — or the air returns. Surveyor follow-up: pressures normal a week after purging — leak, overcharge or moisture, and what proves it?

Question 9

Piston ring calibration?

Accepted Answer

Calibrate rings by groove and gap: feeler top and bottom against the data-plate figure with butt gap proved in the liner. Read vertical clearance top plus bottom with feelers; the total must sit inside the plate figure. Sudden wear jumps mean water through the cooler, dead cylinder oil or abrasive fuel and air. Proving the ring free in its groove matters more than polishing it — stuck rings pump blow-past. Butt gap proved square in the unworn liner band per maker figure before fitting. Surveyor follow-up: one unit high exhaust with low compression — rings, valves or timing, and what do you measure first?

Question 10

Tappet clearance of ae?

Accepted Answer

Auxiliary tappets follow the same hot-cold logic at speed: early-late errors cost volumetric efficiency first. Too little opens early and closes late; too much opens late and closes early — both cost air. Early inlet pumps exhaust back to the manifold; late inlet wire-draws suction and wastes inertia fill. Early-closing inlet chokes the end of suction; late-closing pumps charge back out. Set cold off the peak, prove timing on marks and recheck as gear wears between overhauls. Surveyor follow-up: one AE unit smokes with tappets correct — valve, timing or fuel, and what proves it?

MEP / Marine Electrical — Most Asked Questions

Crankshaft / Bearing / Cylinder

Boiler (motor)

Certificates & Statutory Survey

Piping & Hydraulics

Engine Room - General

Fuel Oil System

Lubrication System

Ship Structure - Plating & Seams

Purifier / Clarifier

Engine Room Auxiliaries (MEP)

Auxiliary Machinery - ER

Gas Cylinder & CO2 Room Safety

Refrigeration Plant

Sounding & Level Measurement

Boiler (MEP)