JonL
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WWSME (Wiltshire)
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Post by JonL on May 28, 2020 11:16:34 GMT
I've just taken a tatty looking filter off the pump feed of my William. I don't think it's ever been used, it's just not that well made, with splits and solder all over the shop.
I'd like to remake it, can anyone suggest which size brass mesh I would require for a good compromise of filtration and blockage resistance?
Thank you,
Jon.
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Post by simplyloco on May 28, 2020 11:28:18 GMT
I've just taken a tatty looking filter off the pump feed of my William. I don't think it's ever been used, it's just not that well made, with splits and solder all over the shop. I'd like to remake it, can anyone suggest which size brass mesh I would require for a good compromise of filtration and blockage resistance? Thank you, Jon. Jon Did you see my SS post where I used a spraygun filter for that task? John modeleng.proboards.com/thread/13166/stirling-single-10-00-scotsman?page=23
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JonL
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WWSME (Wiltshire)
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Post by JonL on May 28, 2020 12:11:46 GMT
I do now you mention it, I'll revisit.
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uuu
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Post by uuu on May 28, 2020 12:35:28 GMT
If you look at a car air or oil filter, you'll see the filter medium is pleated, to present a much larger effective surface area. I've not seen this done on the various finger-filters I've encountered in models, but suggest it would give a better flow and longer intervals between cleaning.
Although the spraygun filter is very neat!
Wilf
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JonL
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Post by JonL on May 28, 2020 13:08:50 GMT
I've got quite a lot of space in there so I figured if I do make one I'll just make it long. Access in the will be almost impossible once the other pipework is done so I would like it to be fit and forget if possible.
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kipford
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Building a Don Young 5" Gauge Aspinall Class 27
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Post by kipford on May 28, 2020 13:14:36 GMT
Wilf You are correct it is done to increase the media surface area which minimises pressure drop and gives a longer life. However it is not just a simple case of providing a lot of pleats. To many pleats and the dynamic losses in the pleat geometry far out way the gains and you get crap performance. A car filter oil or air filter is normally designed to remove particulate around the 5-10 micron mark (human hair is about 90 microns on average). The filters we want for our tenders and water tanks are not really filters but strainers or last chance filters, like John has on his spray gun. Be aware pleated car air filters do not like being submerged in water, they are hydroscopic and this makes the pressure drop even worse and ruins the life. I am using stainless steel meshed fish tank filters on my tender like Midland does. Dave
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uuu
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Post by uuu on May 28, 2020 13:48:33 GMT
I was thinking you could make something like this (with whatever grade of mesh you decide): Wilf
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smallbrother
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Errors aplenty, progress slow, but progress nonetheless!
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Post by smallbrother on May 28, 2020 14:55:53 GMT
I just cut 2 discs of brass about 1" diameter, 1/4" thick. One has a hole just bigger than the copper feed pipe. I wrap the discs at either end of a roll of brass gauze off Ebay and fix the gauze over the discs with 2 jubilee clips. Worked for about 8 years now on quite a few locos. Not pretty but quick and simple. It isn't on view anyway.
Pete.
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JonL
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Post by JonL on May 28, 2020 20:05:36 GMT
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smallbrother
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Post by smallbrother on May 28, 2020 20:34:50 GMT
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JonL
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Post by JonL on May 28, 2020 20:48:31 GMT
Thank you
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uuu
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Post by uuu on May 29, 2020 6:01:36 GMT
On your fit-and-forget idea. If a filter/strainer works, it will get blocked and will need cleaning. If it doesn't get blocked, then it's either not working, or not needed.
Wilf
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smallbrother
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Post by smallbrother on May 29, 2020 7:32:21 GMT
On your fit-and-forget idea. If a filter/strainer works, it will get blocked and will need cleaning. If it doesn't get blocked, then it's either not working, or not needed. Wilf Two of mine are very accessible being in my riding truck/trolley rather than in a side tank. The ones on my large Bagnall however are at the bottom outlets in the saddletank. They are just flat pieces of gauze about 1/2" diameter. I haven't had chance to do a lot of running but I doubt they will perform very well as any crud will easily block that I reckon. They are a bit awkward to get at too with the water supply valves and control rods being directly under them. I need to fix some other problems on this loco before sorting this issue out but I will come up with something better in due course. Pete.
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Post by daveburrage on May 29, 2020 15:57:23 GMT
I might be over simplifying matters, but as long as the mesh is smaller than the smallest injector cone it should do its job. A bit of crud under a ball valve should clear in a few pumps and anything inside the boiler will clear when blown down.
regards
Dave Burrage
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miken
Part of the e-furniture
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Post by miken on May 30, 2020 20:26:21 GMT
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JonL
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Post by JonL on May 30, 2020 20:29:28 GMT
Luckily at the present time it doesn't have any injectors...
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Post by coniston on May 30, 2020 20:30:57 GMT
They look like a good solution, and if fine enough for filtering petrol they should be excellent for our water feeds Chris D
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Post by d304 on May 30, 2020 22:27:18 GMT
Have a look at spray fun filters, small, cheap and disposable..
David
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Post by GWRdriver on Mar 27, 2021 0:03:43 GMT
I've just made a pair of drains & strainers for the side tanks on my loco project (7+ga) and need to install a spool of wire mesh in the strainers. I wondered what wire count would be appropriate for small injectors, say up to 24oz/min. I'm thinking 60-80 or more, and the strainers are very similar to the motorbike fuel strainers mentioned earlier in this thread.
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Post by Jim on Mar 27, 2021 2:20:00 GMT
For the primary water filter I used the tea holder from the tea pot. It is a fine brass mesh and catches any bits of foriegn matter as the water is poured into the tender. I then used water filters from an in ground irrigation system as secondary filters on the water cocks to catch any fine material that had managed to get through the primary filter.
The system works well and so far the wife hasn't twigged to what happened the the tea holder fom the tea pot.
Jim
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