Alfa Laval WHPX 405 Leaking Fuel through the water discharge

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CGEng
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Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby CGEng » Thu Jun 30, 2011 2:09 am

We have an Alfa Laval whpx 405 purifier on board and after a 2000 hour inspection fuel oil is leaking through the water discharge and can be seen in the sight glass. We have replaced the gravity disc several times and all the seals but still no change. If you know why this is happening or how to repair it any information would be appreciated.

CGEng
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Re: Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby CGEng » Thu Jun 30, 2011 10:13 am

I reduced the back pressure down from 2 bar to 1.5 bar and the leaking stopped, however the purifier ran for years at 2 bar. It stopped the leak but there still must be somthing wrong

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JollyJack
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Re: Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby JollyJack » Thu Jun 30, 2011 11:08 am

2 bar seems kinda high, 1.5 is about right. See the comments in the thread about water in lub oil.
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The Dieselduck
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Re: Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby The Dieselduck » Sun Jul 03, 2011 1:51 pm

I am not sure I have much to impart on the subject, except to say that in my experience with Alfa Laval purifiers, there is always a perfectly good explanation for malfunction.

In this case I am sure you've taken the unit apart. I am not familiar with this particular unit, but a careful inspection of the orings should be carried out. Perhaps the bowl is not closing properly, so before you even take anything apart check your water pressure. Sometime operating water has a filter, which gets clogged up giving you lack of sealing pressure. Kinked hoses have also been a problem for me in the past.

Depending on your machine and its control panel, you can run a full diagnostic on the water system, using a stopwatch and measured bucket. Look in the manual for specific instruction.

Another reason for the bowl not closing might be the springs, over time they get compressed and need to be replaced. Check the manual for specs, I've have had to replace a few set of spring to correct this type of issue.

Like I said there is usually a very simple and obvious problem with Alfa Laval machines, so start with the outside variables, in particular operating water, and air too. Is this a new problem? Gradual? Is your back pressure okay? is the gauge accurate?
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jimmys
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Re: Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby jimmys » Wed Jul 06, 2011 10:48 am

Is the specific gravity of the fuel getting near to the specific gravity of the water, a change of fuel can cause this. As we get heavy oil near to a specific gravity of 1.00 this can cause this.

regards

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JollyJack
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Re: Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby JollyJack » Wed Jul 06, 2011 10:50 am

and some of the crap you get now is getting up there
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Big Pete
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Re: Alfa Laval WHPX 405 Leaking Fuel through the water discharge

Postby Big Pete » Mon Jul 11, 2011 12:02 pm

Densisty is a big issue, I believe the HFO specifications permit a density 0f 1010, half way between Fresh water and sea water.
One other thing, is the purifier running at the correct speed? If the centrifugal clutch pads got dirty during the overhaul they may be slipping.
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