Hand Feed Pump Plans

[Lopez Mike]

I use a home made pump with the cylinder made from a block of aluminum and a piston (with O-rings) made out of mild steel. Is a revolting thing to look at, rusts all of the time, and generally is an affront to engineering good sense.

But it pumps water and I use it to test my boiler.

So there is the bottom of the line in design and execution.

My next pump will be made of an old bronze stern shaft packing box with a bronze or S.S. piston with no O-rings and the sealing taken care of by the original flax and sheep snot packing.

[PeteThePen1]

Hi Folks and especially friends in the US

Can I slip in a relevant addenedum to this thread? Here in the UK if one is to steam on our canals and some of our rivers with the intention of pumping water from those bodies, some form of filtration might be advisable. I am currently looking into the idea of fitting a water filter just downstream of the feed seacock (close to the hand feed pump!).

I have spotted this water filter which is widely available here and looks to be of US design and manufacture, indeed it comes threaded NPT (adaptors for BSP supplied). The maker or importer is BWT.

http://www.screwfix.com/p/high-capacity ... t-10/16747

Do US based friends recognise the product and if so, is it also available with a clear plastic bowl. The latter would be useful to keep an eye on the level of sediment that the filter has trapped.

Regards


Pete

[DetroiTug]

Hi Pete,

I would look for a 1/2" "Perko Sea strainer", it can be seen on the tug in the lower portion of these pics. They show up on Ebay occasionally at a fair price. Have a clear cylinder with stainless steel basket strainer. I've never had to clean this one and have never had any foreign debris foul the pumps.





-Ron

[barts]

that bronze unit is nice... if the unit is not visible, consider a Sherwood raw water filter. These are plastic and available in a wide variety of sizes. Same idea - stainless screen, removable clear plastic cover.

A search on ebay for for 'raw water strainer yields both bronze and plastic examples: http://www.ebay.com/bhp/raw-water-strainer

- Bart

[Lopez Mike]

I use a small plastic unit with about a 1.25" dia. by 2" long S.S. screen on the input of my Hypro pump and have not had a single pump valve fouling incident for a couple of years. And Hypros don't like crud at all.

This on a condensing setup. If I were pumping from fairly fouled water I would think about an ordinary under sink filter housing like you are looking at with the largest pore size they sell. You don't need fractional micron filtering at all.

Any building supply or plumbing place will stock clear ones. Like this housing. Filters elements are five to ten bucks.
http://www.homedepot.com/p/Pentek-15811 ... /206017090

[fredrosse]

I had a very fine filtering media domestic water filter on a previous boat with a flash boiler, feed pump taking suction thru this filter. After about 1-1/2 years the filter started to clog, which starved the feed pump, and feedwater flow kept diminishing. But I didn't know that. The engine kept running better and better, because of the great superheat I was getting based on reduced water flow. The boiler coils were stainless, so they could take the heat, and the single acting engine had good lubrication from the crankcase. All went well until the feed flow got so low that 950F steam was coming out, but not quite enough steam for the engine. This problem was corrected with a new filter cartridge, but I nearly burned up the insulation on the steam pipes.

Now for feedwater I use a standard 40 mesh plumbing "Y" strainer, with a blowdown port. Many of these come with 20 mesh screen, in my view too coarse for a small pump such as many engine driven ones. With 40 mesh, never a problem with pump valves, and I have cleaned this filter every year. The Y strainer would eventually clog up with rust particles from my feed tank if I did not regularly clean it.

[PeteThePen1]

Thank you all for your comments and suggestions.

I love the bronze filter that you referenced Ron, but I fear that will have to wait until I win the lottery. The advisory shipping costs and import duty amounted to over $70 before taking into account the fact that none of the reasonably priced vendors will ship to the UK.

Mike's suggestion is exactly what I had in mind, although I have not been able to find them this side of the pond. However. Bart's raw water filters do seem to be available here at a reasonable cost, so will go on the list.

I must look more closely at Fred's suggestion of a Y filter. A quick Google seems to suggest that they are available here at every plumber's merchant and DIY store. That will probably put them at the top of the list.

Thank you all. Once again the Forum has come up trumps. I hope also that our colleague who kicked off this thread has got what he wanted.

Regards

Pete

[DetroiTug]

Pete,

I bought that one on Ebay for 70 dollars. They are about 300 new. The strainer is just a stainless steel cylinder with holes about .08" diameter. It has served well.

-Ron

[PeteThePen1]

Thanks for the update Ron. Yes, I did have a good browse of eBay, but the best offer was about $110 before shipping. Perhaps we ought to use the sales section of the Forum to flag up bargains if we spot them. The trouble is that one has be trawling eBay a good deal to spot that sort of thing.

Updating on the issue of this thread, hand pumps and filtration, I can report that I was correct in my memory that the hand pump is not protected with a filter. Tracing the pipe runs, it appears that the same is true for the injector, but there is one for the Hypro.

Having sat in the cool (10c) garage and pondered the pipe runs and possibilities it strikes me that a Y filter just inboard from the seacock would be the neatest solution. It might also be an occasion to see if I can smooth the run from the injector, although it works very well as it is. I might also try to simplify all the pipe runs as I can see a few opportunities for somewhat better routes. Some of the photos you all have posted have such neat pipework - I feel a degree of peer pressure to try to match your standard!

Regards


Pete

[DetroiTug]

Here is another solution. Inline filter. It really shouldn't take much filter area. I'm a bit hesitant about these plastic parts (mine has a clear lexan? cylinder). They are typically mounted below the water line, if it cracks.. I intend to mount a seacock on the thru-hull for when it is left unattended.

http://www.mcmaster.com/#5166k66/=10fp4pl



-Ron