Fresh water filter ......where I the system ?

[clyst]

Hi all
Just noticed that the large Aqua spin on filter is on the suction side of FW pump . Logic says it should be on the discharge side to give purest water to the system . What does the panel think ? .....On the suction side or discharge ??

cheers

 

[VicS]

why would it give purer water if on the discharge side of th e pump ??? ;
Please explain the logic of which you speak

 

[NormanS]

Probably the best setup is to have the filter just before a dedicated tap. After all water for washing etc doesn't need filtered.
A fine gauze filter just before the pump is also good, as it can prevent little bits of grit from sticking under the valves in the pump.

 

[theoldsalt]

Hi Clyst,

The recommended position appears to be on the pressure side of the pump. See typical installation on this pdf download.

http://www.google.co.uk/url?sa=t&rc...ooDwAg&usg=AFQjCNGxzTy7UYK2OANElm6osbH2ij69-w

 

[alahol2]

Ours is too far from the tap and any water left in the pipes between filter and tap can pick up an 'off' taste if the boat is left for a couple of weeks. Means we have to remember to pump a bit of water before filling the kettle on arrival. So, nearer to the tap would be better.

 

[clyst]

Thank for your replies chaps.
Reason for suggesting it would be better on pump discharge is as Alahol2 says .....water lying in the pipe work . I have considerable pipe work before the distribution manifold . I appreciate having a filter close to,each sink would be ideal but having 4 sinks I don't fancy forking out£100+ each year to renew them .

 

[VicS]

Thank for your replies chaps.
Reason for suggesting it would be better on pump discharge is as Alahol2 says .....water lying in the pipe work . I have considerable pipe work before the distribution manifold . I appreciate having a filter close to,each sink would be ideal but having 4 sinks I don't fancy forking out£100+ each year to renew them .

Not then a question of fitting to the pump discharge vs the suction as you originally asked but more a requirement to fit as close as possible to the tap or taps from which drinking water is normally drawn. I don't know how many galleys your boat has but one per galley would seem sensible.

 

[NormanS]

Not then a question of fitting to the pump discharge vs the suction as you originally asked but more a requirement to fit as close as possible to the tap or taps from which drinking water is normally drawn. I don't know how many galleys your boat has but one per galley would seem sensible.

That is why in #3, I suggested having the filter immediately before a dedicated tap. There is no point in filtering water which is going to be used for other than drinking. I would be surprised if the OP drinks water drawn from all of his four sinks.

 

[clyst]

Sorry for all the confusion chaps..... I was trying to finish off an Xmas bottle of JD. The biggest confusion was That I assumed you knew the system layout onboard . Doh !!!
Let me explain now I'm without JD ..... The FW pump is sited about 18" from the FW tank discharge with the filter in between . So stagnant water lies in the rest of the system .
Good point about filters not needed at every outlet .
Apart from the stagnant water issue I wasn't sure whether there were pressure/technical issues in moving the filter to the discharge side of the pump.

 

[VicS]

Sorry for all the confusion chaps..... I was trying to finish off an Xmas bottle of JD. The biggest confusion was That I assumed you knew the system layout onboard . Doh !!!
Let me explain now I'm without JD ..... The FW pump is sited about 18" from the FW tank discharge with the filter in between . So stagnant water lies in the rest of the system .
Good point about filters not needed at every outlet .
Apart from the stagnant water issue I wasn't sure whether there were pressure/technical issues in moving the filter to the discharge side of the pump.

I think the spec gives a max operating pressure. Well within the normal operating pressures expected for FW systems Id guess so there should be no problem from that point of view.

The diagram in old salt's link shows the filter on the pressurized part of the system and close to a tap rather than the pump discharge although I don't remember anything written.

It is desirable to have a strainer/ filter on the pump suction to guard against the effects of debris in the pump valves. Maybe yours has been fitted with that function in mind.

Sorry for being a bit vague about the PDF in old salt's link. This computer wont download it fully. I had to fire up the old one last night to read it!