[U.S. wfp USER]

The ro membrane i ordered came with an accessory kit.

It contains a piece of plastic pipe about 2 inches long with o-rings inside it and 4 extra o-rings.

What are these for?

[JM123]

they are for linking 2 4040 membranes together in a 80inch housing - you can throw it away

[U.S. wfp USER]

Thanks.

The prefilters I have, each have 1" inlet outlets.

The RO has a 1/2" inlet outlet.  Does it make a difference whether I reduce the water flow coming from the prefilters?

Where in line does a booster pump go?

Before or after the prefilters?

Also does sediment go before carbon or the other way around?

Thanks.

[Paul Coleman]

Thanks.

The prefilters I have, each have 1" inlet outlets.

The RO has a 1/2" inlet outlet.  Does it make a difference whether I reduce the water flow coming from the prefilters?

Where in line does a booster pump go?

Before or after the prefilters?

Also does sediment go before carbon or the other way around?

Thanks.

On my system the pump is before the pre filters.  Withput looking I'm not sure about the order of pre filters. I THINK sediment comes first butr don't rely on that.  Will be changing mine over in the next few days.

[Pj]

Thanks.

The prefilters I have, each have 1" inlet outlets.

The RO has a 1/2" inlet outlet.  Does it make a difference whether I reduce the water flow coming from the prefilters?

No, you can reduce it to whatever size you like really.

Where in line does a booster pump go?

Before or after the prefilters?

Before prefilters, mains water into booster, booster into prefilters, prefilters into membrane, membrane into di vessel = PURE into tank.

Also does sediment go before carbon or the other way around?

Sediment then carbon

Thanks.

OK?

[JM123]

it goes like this

1 - sediment filter

2 - carbon filter

3 - booster pump

4 - ro

the booster pump should always be after the prefilters as it puts unnecessary stress on the housings, let the pump draw the water through the prefilters (which works better anyway) and then from pump to ro housing.  Another reason for this is that as the prefilters age you will notice a pressure drop across the filters, therefore if you have the pump before the prefilters then you will lose 10/20/30psi by the time the water reaches the membrane - on the other hand if you set it up pump after prefilters then there is no pressure drop before membrane, only feed rate into the pump inlet slows down, this is evident in a reduced product output.

[Paul Coleman]

it goes like this

1 - sediment filter

2 - carbon filter

3 - booster pump

4 - ro

the booster pump should always be after the prefilters as it puts unnecessary stress on the housings, let the pump draw the water through the prefilters (which works better anyway) and then from pump to ro housing.  Another reason for this is that as the prefilters age you will notice a pressure drop across the filters, therefore if you have the pump before the prefilters then you will lose 10/20/30psi by the time the water reaches the membrane - on the other hand if you set it up pump after prefilters then there is no pressure drop before membrane, only feed rate into the pump inlet slows down, this is evident in a reduced product output.

Just to be clear on this:  Are you saying that if the pump is AFTER the pre-filters then the water output drops?

[JM123]

No, the output only drops when the prefilters are knackered (sediment clogged).

Visualise it for a moment.

If the pump is before the prefilters then you can have a pressure drop before the membrane (across the prefilters) but if the pump is after the prefilters then there is no pressure drop - understand??

[Paul Coleman]

No, the output only drops when the prefilters are knackered (sediment clogged).

Visualise it for a moment.

If the pump is before the prefilters then you can have a pressure drop before the membrane (across the prefilters) but if the pump is after the prefilters then there is no pressure drop - understand??

OK.  I got that now thanks.
I just wanted to re-visit this thread because I changed my pre filters yesterday and have now had a closer look at how my RO is set up and it's not the way I thought.

It goes like this:-

sediment pre filter

booster pump

carbon pre filter

membranes

di

i.e. the booster pump is BETWEEN the two pre-filters.


I did contact the supplier and am assured that this is fine so now I don't know what to think.  The supplier also stated that it is not the only way to set it up though.  I haven't yet measured water production since changing the pre filters but will do so in the next few days.

[JM123]

I just hopefor your sake your carbon housing is pressure tested to at least 50% more than he switch setting of the booster pump.