Fault Finding 2

[Big Pete]

15 years ago I was "on board co-ordinator" (Company spy) on an oil tanker owned and manned in Batumi, Georgian Republic, (Former USSR). I represented the British management company.
It was a very scary trip.
The Chief Engineer informed me that one of the Laval Purifiers had to be cleaned manually because the automation did not work. The Electrician informed me that the automation was fine, the problem was with the purifier.
I asked the engineer's a few basic questions about the system, for instance there were 2 header tanks, high and low supplying operating water to the Heavy Oil, Gas Oil and Lube oil Purifiers. I found that they thought the upper tank supplied water to the Fuel purifiers and the lower one to the L.O. purifiers. In fact the upper tank supplied high pressure water to all 3 purifiers and the lower tank low pressure water to all 3.
Nobody knew where any of the water filters where (when I checked they had all been removed) and nobody knew how to open & close the bowl using the manual valves.
There were a Chief, Second, Third, & Fourth Engineers, Electrician and about 4 Motormen Fitters all had been on the ship for years.

I checked the purifier next time it was dismantled, guess what I found?

[Dieseldame]

Great story BP, I'm thinking that maybe the purifier was working just fine despite its operational environment?

DD

[JK]

I laughed at your post because I have run into the engineer/electrician thing many times before:
it's not mechnical, it's electrical; no it's mechanical, not electrical.

I am almost afraid to find out, but I'll bet that everything was so chocked with mud\sludge that it was a miracle it was working at all. Or did they take the disc stack out because it keept getting dirty

[The Dieselduck]

Hey whats wrong with taking the stack out, ehehehe. Thats pretty funny.

[Big Pete]

Don't even joke about it Martin,
I was Chief on an old tanker with 2 V12 Pielsticks, the original L.O purifiers ( 1 per engine) had long been out of service and a single, totally indaquate, little purifier installed instead.
AS a consequence the main engine L.O. filters got dirty very quickly. This meant the duty engineers had to change over the filters and clean them during the night. They decided to solve this problem by punching big holes in all the filters with a Marlin spike.
I explained to them that this was very dangerous, effectively the engines were running without any filters at all.
I then had the filter gauzes replaced ashore and refitted, but within a few days the engineers had punched holes in them again.
I asked them why they had punched holes in the new filters, instead of just taking them out. They told me it would be dangerous to run the engine without filters, but by punching holes in the filters the engine was still protected but they didn't have the extra work of cleaning the filters!!!
They thought I was very stupid for not understanding this.

[JK]

Big Pete, very good reasoning on their part. Obviously 50% of the LO is being filtered in some fashion

In this culture of blaming the Captain/Chief Engineers and throwing them in jail, I have to ask how your nerves stand it !?!?

[Big Pete]

I used to think something similar myself, but, when you think about it, if you have several 10 mm diameter holes right through a filter, the oil will take the line of least resistance, and even if some goes through the mesh, the debris filtered out will not stay on the upstream side of the filter, but will be washed through the large holes with the oil flow.

I have had similar arguements, ( with British Engineers!) over the Boll & Kirch Filters on MaK engines. These consist of a series of concentric wire meshes, with the gaps between them alternately sealed at the top and bottom. All the filter meshes are operating in parrallell, but many people are convinced that they operate in series and therefore that small damages to one mesh do not matter.

It is now my firm opinion that if it is supposed to be a 40 Micron filter, then any part of the filter with a hole in it larger than 40 micron should be scrapped, and that goes for the sealing arrangements as well.

B.P.

[JK]

We changed most of our manual LO filters out to automatic backwash filters.

[Big Pete]

We have wondered off from the original purifier tale, but the end result of that was that when the bowl had been stripped down, still attached to the purifier, I tested the operating water and only got a feeble dribble.
I got the crew to remove the bowl, which they had never done before, and the brass water distributor underneath the bowl was choked with scale, after cleaning that everything worked perfectly.

[JK]

Never had the bowl out...amazing.




It seems all the engineers that read the forum are rather shy and do not want to post,

[Joe Shemoe]

I used to think something similar myself, but, when you think about it, if you have several 10 mm diameter holes right through a filter, the oil will take the line of least resistance, and even if some goes through the mesh, the debris filtered out will not stay on the upstream side of the filter, but will be washed through the large holes with the oil flow.

I have had similar arguements, ( with British Engineers!) over the Boll & Kirch Filters on MaK engines. These consist of a series of concentric wire meshes, with the gaps between them alternately sealed at the top and bottom. All the filter meshes are operating in parrallell, but many people are convinced that they operate in series and therefore that small damages to one mesh do not matter.

It is now my firm opinion that if it is supposed to be a 40 Micron filter, then any part of the filter with a hole in it larger than 40 micron should be scrapped, and that goes for the sealing arrangements as well.

B.P.

I agree. Boll & kirch filters are reliable however with the damage or whole larger than 40 micron it defeats the purpose and should be replaced.

Joe
http://www.fluitek.com

[JK]

Welcome to the Forum, JoeShemoe, love the handle.
Post often, love to hear from you.