Feed/expansion vessel options

[Arducius]

I am about to plumb in my back boiler but have so far been unable to find a suitable feed/expansion tank. I am hoping to have an open system so I can top up the water when necessary, as opposed to a closed system using an accumulator and a PRV.

Either I am not very good at searching or I am looking for the wrong thing, so does anyone have any suggestions for a vented expansion vessel, preferebly one that looks good as it'll be on show? I know I need to calculate the capacity of the system and size the vessel appropriately.

My boat previously had a tupperware box as the expansion vessel (on the ond, now removed system) but I think I'd rather have something a little more robust!

Thanks in advance!

[Robbo]

Search for "Radiator Expansion Tank", that should come up with some results in Google

[bottle]

Probably not big enough

 

http://www.ebay.co.uk/itm/Universal-2-Litre-Polished-Aluminium-Alloy-Header-Expansion-Water-Tank-with-Cap-/151372891620?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item233e8705e4

[Arducius]

Thank you both, I have been searching for "feed tank", "expansion tank", and variations on that theme. Header tank seems to bring back much more likely candidates!

 

Now I just need to figure out how much water the radiators, back boiler and pipes hold...

[The Bagdad Boatman (waits)]

wander round a lorry scrapyard.

[nbfiresprite]

There this one on e-bay http://www.ebay.co.uk/itm/Barge-Boat-Header-Tanks-Toilet-Waste-Tanks-Etc-/251650605686?pt=UK_CarsParts_Vehicles_BoatEquipment_Accessories_SM&hash=item3a978b8276

 

[Guest]

I have seen scrap fire extinguishers used to good effect, turned upside down with a fitting in the hole where the valve once lived. Usually obtained freely, we used to use them for fuel tanks and expansion tanks in our banger racing days. Very robust and should look OK when painted properly. Saw one with traditional roses painted on it.

[Murflynn]

A compact toilet cistern is effective and has a ball valve to keep the system topped up as well. Screwfix.

[mark99]

Look In the what have you fettled for your boat today thread In this forum. A couple of options there. Ie alloy or polished stainless.

[bag 'o' bones]

We used a ford transit coolant header tank:

http://www.ebay.co.uk/itm/Ford-transit-expansion-bottle-/181540193671?pt=UK_CarsParts_Vehicles_CommercialVehicleParts_SM&hash=item2a44a38587

 

you can find them in scrapped transits built between the years 94'-2000

 

They come complete with a very handy mounting bracket. You also monitor the water level as they are translucent. A lot better made than some expansion tanks made specifically for the purpose!

Edited October 2, 2014 by bag 'o' bones

[micky1010]

Hi,

 

I hope someone can help as a lot of people seem to know about these systems and I haven't a clue, my boat has a back boiler feeding 1 radiator with a run to the stern for an expansion tank. I have used it for the first time today and even thought the stove is nice and hot the radiator remains cold.

Is there a way of checking how much water is in the system and how much should there be?

If there is water in it is there a fix without having to put in a pump, presumably the system has worked fine in the past as it has never been removed or changed and the previous owners had the fire going most of the time as they were liveaboards?

[bottle]

Check there is water in the expansion tank, bleed the pipe work/radiator you probably have an air lock.

 

Try to maintain water above outlet of expansion tank, so that air cannot get into the system.

 

May need two people, if lots of air in system, one to bleed (the system) and one to keep the tank topped up.

 

When finished do not have the expansion tank too full as it needs some space for the expanding water to go.

[micky1010]

Thanks Bottle, I'll give it a go.