Diesel primary filter - vacuum or pressure side?

[Robih]

Evening all,

I'm fitting a water separator/fuel filter in the genny diesel supply line (contractors fitted genny with no filtration). Can anyone advise whether the filter is best placed on the vacuum side or the pressure side (between tank and fuel pump or between fuel pump and injection pump)? The filter is a Parker 120AT, I can't find any guidance on the Parker/Racor website.

**EDIT** I have determined that the 120AT can be used in pressure deployment up to a maximum 7psi in the supply line so it looks like either is fine assuming its not high pressure.

Any further guidance would be appreciated.

Rob

 

[Wing Mark]

Do you want to keep the pump clean?

 

[PaulRainbow]

Fit it before the lift pump.

 

[vas]

+1 on what previous posters state.
I do have a fuel pressure sender fitted on the Main filter between lift and high press pump. It can easily exceed 1bar, so that filter would be unsuitable anyway...

Cheers

V

 

[Shanty]

As PaulRainbow says, the filter should go before the pump. Filters work best when fluid is drawn through them, rather than pushed in to them. Pulling gives the filter a relatively smooth flow. Pushing gives the filter the turbulence generated by the pump.

 

[Robih]

Thanks all, every day is a school day……

 

[Mistroma]

As PaulRainbow says, the filter should go before the pump. Filters work best when fluid is drawn through them, rather than pushed in to them. Pulling gives the filter a relatively smooth flow. Pushing gives the filter the turbulence generated by the pump.

It also helps to fit a filter before anything you want to protect from small particles or water. It will then filter out the small particles or water before they reach anything expensive. Even the small electric lift pump is stupidly expensive on my Yanmar.

Of course the really expensive stuff is after the engine's own filter. Eye-watering.

 

[Bilgediver]

Do you want to keep the pump clean?

Some lift pumps have a filter basket . Can save problems if it only gets clean fuel