water maker filters

[voyager35]

I am starting to resurrect an old Seafresh water maker that is fitted to a boat that i am slowly restoring and hasn't been used for a long time. The system has three inline prefilters labeled OIL, 50 microns and 5 microns. Nowhere that I have found sell a oil prefilter,and no modern watermakers seem to have them fitted. The filters are Atlas 10inch.
My question is do i need the OIL prefilter and if so does anyone know whereto buy them
Thank you

 

[geem]

I am starting to resurrect an old Seafresh water maker that is fitted to a boat that i am slowly restoring and hasn't been used for a long time. The system has three inline prefilters labeled OIL, 50 microns and 5 microns. Nowhere that I have found sell a oil prefilter,and no modern watermakers seem to have them fitted. The filters are Atlas 10inch.
My question is do i need the OIL prefilter and if so does anyone know whereto buy them
Thank you

No you don't need an oil prefilter but since you have the filter housing installed I would fit a carbon block filter in there to protect the HP membranes from chlorine in tap water

 

[Spirit (of Glenans)]

There is an article in the current PBO by a nonagerian who designed and built his own watermaker, perusal of which might help in your project.

 

[Clancy Moped]

I used to buy ours from swimming pool shops.

 

[dgadee]

I presume the oil filter is for use in harbours? I never use mine there due to the possibility of oil damaging the costly membranes.

 

[Ningaloo]

If you are in EU you can get these from SVB.

 

[geem]

I used to buy ours from swimming pool shops.

Aquarium supplies are where mine come from. Lots on eBay and cheap

 

[roaringgirl]

We just have a strainer and a 5 micron. When flushing from the tank, it also goes through a charcoal filter to protect from chlorine.

Our saltwater intake is about 40cm below the waterline, so the only oil the membranes need protecting from is the kind that doesn't float on the surface.(?!)

 

[geem]

We just have a strainer and a 5 micron. When flushing from the tank, it also goes through a charcoal filter to protect from chlorine.

Our saltwater intake is about 40cm below the waterline, so the only oil the membranes need protecting from is the kind that doesn't float on the surface.(?!)

We have the stainless steel strainer as well. The first prefilter is 20 micron. The second is 5 micron. Since we have a high power centrifugal boost pump that will deal with pressure drop we can run pleated 20 micron filters and cheap block type 5 micron filters. The 20 micron filters are cleanable. They get pretty manky. The 5 micron filter stay clean for a long time due to the 20 micron filter. Washing the 20 micron has a downside. There is a risk of contamination on the wrong side of the filter by cleaning and reusing it. However the 5 micron filters are throw away. They catch any crap passes by the 20 micron filter during normal use or by the process of washing it. This provides great protection to the HP membranes.

 

[roaringgirl]

We have the stainless steel strainer as well. The first prefilter is 20 micron. The second is 5 micron. Since we have a high power centrifugal boost pump that will deal with pressure drop we can run pleated 20 micron filters and cheap block type 5 micron filters. The 20 micron filters are cleanable. They get pretty manky. The 5 micron filter stay clean for a long time due to the 20 micron filter. Washing the 20 micron has a downside. There is a risk of contamination on the wrong side of the filter by cleaning and reusing it. However the 5 micron filters are throw away. They catch any crap passes by the 20 micron filter during normal use or by the process of washing it. This provides great protection to the HP membranes.

The 5 micron filters don't last as long as they would if we also had a 20 inline, but the cost is low.

 

[dgadee]

We just have a strainer and a 5 micron. When flushing from the tank, it also goes through a charcoal filter to protect from chlorine.

Our saltwater intake is about 40cm below the waterline, so the only oil the membranes need protecting from is the kind that doesn't float on the surface.(?!)

Oil mixed with Fairy Liquid, for example, will lie beneath the surface I have been told.

 

[voyager35]

Aquarium supplies are where mine come from. Lots on eBay and cheap

Thank you i never thought to look there i had assumed the filters were a specialist item

 

[typhoonNige]

Wherever you source your prefilters you should be sure they are polyester and not paper ones.

 

[geem]

Wherever you source your prefilters you should be sure they are polyester and not paper ones.

If you use two filters 20 and 5 micron, the 20 can be paper. Any deterioration in the paper filter will be caught by the 5 micron. If you are using a single filter it should be polyester and disposed of rather than cleaned. There is a risk of contamination of the HP membranes if you clean a single filter and replace

 

[voyager35]

No you don't need an oil prefilter but since you have the filter housing installed I would fit a carbon block filter in there to protect the HP membranes from chlorine in tap water

I assume that you would fit the carbon block filter after the 5 micron one so it will stay clean of sediment

 

[dgadee]

I assume that you would fit the carbon block filter after the 5 micron one so it will stay clean of sediment

Mine is between tank and taps/filters. No sediment at all.

 

[geem]

I assume that you would fit the carbon block filter after the 5 micron one so it will stay clean of sediment

You need to install the carbon filter in the flushing pipe not the sea water inlet pipe.
On my set up, I have a 1 micron filter straight after the pressurised water pump then a carbon block filter. This way the whole boat gets good tasting drinking water from the water tank. The tee off to flush the water maker is also protected by the carbon block filter.

 

[typhoonNige]

Probably better to have the carbon filter upstream of your 1micron filter. In my experience carbon filters can shed particles which you wouldn’t want on your Watermaker membrane.

 

[dgadee]

Probably better to have the carbon filter upstream of your 1micron filter. In my experience carbon filters can shed particles which you wouldn’t want on your Watermaker membrane.

Which carbon filter do you use?

 

[typhoonNige]

Sorry, my last post was intended as a reply to geem. I don’t use a carbon filter with my water maker or on my water supply. I tried using them when processing seawater for the production of calibration standards in a previous life as a chemical oceanographer. It was my experience that small particles of carbon were shed so I didn’t routinely use them. I don’t recall what brand I used