Volvo Penta Pre filter Part Number 877762

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swifty

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What is the correct filter required for this filter unit, Marine Parts Europe lists 2, 10, and 30 micron on my engine this is the pre- filter,there is a secondary canister type filter volvo penta 3825133. Researching on the internet filter 3825133 seems to be 20 micron.
 
Ideally you want progressive filtration. The canister one will be something in the 2 to 5 micron size. I would stick a 10 micron filter in the primary. Having said that, you could put a 2 micron in the primary, as they are very easy to change, and extend the life of your canister filter almost indefinitely. Can't really see any reason to use a 30 micron filter, Unless you have three stage filtration.
 
all about if you do change both filters at the same time or do the pre-filter more often (ideally) than the engine filters. You can happily go with a 10m for pre-filter if you change both of them at the same time. Another factor to consider is the area you boat and condition of the fuel. If you can filter the junks in your fuel tank first and block the pre-filter, you know your engine filters are still fine can within 10min you can change the pre-filter in the sea but engine filters usually take longer and harder to change (some boats almost impossible unless you do a major surgery of the floor!)
 
Normally you have a coarser mesh on the prefilter which is mounted remotely from the engine on a bulkhead and the engine mounted filter is a fine filter.So the guy who posted 30m meaning 30 micron is the normal way of doing it.That way the prefilter takes all the large debris down to 30 micron and fine debris can pass through to the engine mounted filter where it is stopped.
 
Bandit said:
Normally you have a coarser mesh on the prefilter which is mounted remotely from the engine on a bulkhead and the engine mounted filter is a fine filter.So the guy who posted 30m meaning 30 micron is the normal way of doing it.That way the prefilter takes all the large debris down to 30 micron and fine debris can pass through to the engine mounted filter where it is stopped.
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OK, but why not put a 10m in the pre filter, which will stop more crap reaching the engine filter and is usually much easier to change.
 
inception said:
all about if you do change both filters at the same time or do the pre-filter more often (ideally) than the engine filters. You can happily go with a 10m for pre-filter if you change both of them at the same time. Another factor to consider is the area you boat and condition of the fuel. If you can filter the junks in your fuel tank first and block the pre-filter, you know your engine filters are still fine can within 10min you can change the pre-filter in the sea but engine filters usually take longer and harder to change (some boats almost impossible unless you do a major surgery of the floor!)
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Im trying to make sense of that.

I run a 10 micron pre filter to catch smaller stuff than a 30 micron. I realise I could have to change them more often but that’s easy.

If using a 10, why do I have to change the engine 2 micron filters at the same time but not with a 30 micron pre filter?

Bit confused :)
 
swifty said:
A Volvo Penta TAMD 31B.
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I have kad32 engines which are the same basic engine except with a supercharger added.
I have spin on type filter which according to an internet search is 20 micron rated.

The filter of the identical make/spec was fitted by a respected marine engineer during service of kad32's on my previous boat and also my present boat . So I take that as a recommendation.

Micron ratings do not mean 100% of the particles of that rating will be captured.
 
I have a racor 500 series filter housing and I use a 30 micron filter and you can crossreference that number and you will find numerous manufacturers like parker Knoll - fleetguard etc
 
The main reason behind not using a very fine filter before the main filter is to avoid differential pressure . The job of the prefilter is to filter large particles like grit, sand etc. without building up and causing a high differential pressure. The design of the pre-filter is to act like a centrifuge as well and separate water from fuel. if the fuel can't get through easily then the centrifugal effect won't happen and in fact it can pass through water straight into the engine.
 
inception said:
The main reason behind not using a very fine filter before the main filter is to avoid differential pressure . The job of the prefilter is to filter large particles like grit, sand etc. without building up and causing a high differential pressure. The design of the pre-filter is to act like a centrifuge as well and separate water from fuel. if the fuel can't get through easily then the centrifugal effect won't happen and in fact it can pass through water straight into the engine.
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Thanks for the answer. Never knew that :encouragement:
 
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