On 2008-05-31 03:27:37 +0100, John Stumbles said:

On Sat, 31 May 2008 00:41:41 +0000, John Stumbles wrote:

Cheapo garden spray pump and suitable adaptor(s) to get it onto the
filling hose connection. And a bit of elbow grease.

Oh and drop the pressure in the system before doing so or you'll never get
any in.

I made one of these to be able to refill my secondary circuit (used for
the workshop and supplied with heat via a plate heat exchanger).
This circuit is substantially dosed with Alphi-11 inhibitor, containing
antifreeze, which is quite expensive, so I wanted to be able to keep
the liquid if it's necessary to partly drain down and put it back
afterwards.

The recipe was the bog standard large capacity Hozelock sprayer from
wherever. The aluminium tube forming the lance will fit well into
an 8mm brass compression fitting. I used a 8x8mm coupler From there
I adapted upwards using a short piece of 8mm copper tube to a 8x15mm
adaptor with male tail with that going into a 15mm x 3/4 BSP male
fitting - i.e. something onto which the filling loop will go.

I've found that I can get the pressure up to about 1.5 bar with this.
On refilling, I add a little more fresh Alphi-11 to the mix and
finally top up with mains water to 2 bar. This avoids dilution.

I agree, though, the last few sprayer tank fulls beyond 1 bar are hard work.