Hi,

Just buying the fittings for the F&E tank for a 250l DIY heatbank.

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

The only think I can see is air might clear better with a 22mm expansion
pipe. On the fill pipe, though I have mental water pressure on the mains, I
doubt a standard ballcock could much exceed the capacity of a 15mm fill
pipe.

Any thoughts gratefully received before I hit Toolstation...

Ta

Tim

Tim S coughed up some electrons that declared:

Hi,

Just buying the fittings for the F&E tank for a 250l DIY heatbank.

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

I'll quickly add of course, that the expansion connection will overhang the
tank in the time honoured fashion, not use a tank connector - but killing
birds etc...

On Wed, 03 Jun 2009 22:18:19 +0100, Tim S wrote:

Hi,

Just buying the fittings for the F&E tank for a 250l DIY heatbank.

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

I think the general rule is 15mm feed, 22mm vent.



--
John Stumbles -- http://yaph.co.uk

The clairvoyants' meeting has been cancelled due to unforseen circumstances.

YAPH coughed up some electrons that declared:

On Wed, 03 Jun 2009 22:18:19 +0100, Tim S wrote:

Hi,

Just buying the fittings for the F&E tank for a 250l DIY heatbank.

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

I think the general rule is 15mm feed, 22mm vent.




Thanks for the confirmation John. I'll do exactly that...

Cheers

Tim

On Wed, 03 Jun 2009 22:18:19 +0100 someone who may be Tim S
wrote this:-

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

The only think I can see is air might clear better with a 22mm expansion
pipe. On the fill pipe,

One pipe, generally 15mm, allows water to flow into the system and
also allows water to expand back into the tank. After the system has
been filled water flows up and down this pipe as the water in the
heatbank expands and contracts. This is the feed and expansion pipe.

The other pipe, 22mm, allows air and water to escape from the
pipework during filling and afterwards. If water flows over the top
of this pipe [1] then the system is designed or installed wrongly.
This is the vent pipe.

Those pipe sizes are house and other small building ones.

[1] during filling a large air bubble may force water over the top.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen coughed up some electrons that declared:

On Wed, 03 Jun 2009 22:18:19 +0100 someone who may be Tim S
wrote this:-

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

The only think I can see is air might clear better with a 22mm expansion
pipe. On the fill pipe,

One pipe, generally 15mm, allows water to flow into the system and
also allows water to expand back into the tank. After the system has
been filled water flows up and down this pipe as the water in the
heatbank expands and contracts. This is the feed and expansion pipe.

The other pipe, 22mm, allows air and water to escape from the
pipework during filling and afterwards. If water flows over the top
of this pipe [1] then the system is designed or installed wrongly.
This is the vent pipe.

Those pipe sizes are house and other small building ones.

[1] during filling a large air bubble may force water over the top.



Thanks David. Have ordered parts...

Now for the joy of hole drilling a GRP tank :-ooo

Cheers

Tim

Tim S wrote:
Hi,

Just buying the fittings for the F&E tank for a 250l DIY heatbank.

Any reason to take 22mm for the fill and vent/expansion connections?
Most smaller F&E tanks I've seen have had 15mm for both.

The only think I can see is air might clear better with a 22mm expansion
pipe. On the fill pipe, though I have mental water pressure on the mains, I
doubt a standard ballcock could much exceed the capacity of a 15mm fill
pipe.

Any thoughts gratefully received before I hit Toolstation...

I think the logic of using 22mm for the vent is to make it much harder
for this to get blocked by scale or other obstructions...

--
Cheers,

John.

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John Rumm coughed up some electrons that declared:

I think the logic of using 22mm for the vent is to make it much harder
for this to get blocked by scale or other obstructions...


Good point - hadn't thought of that...