loft coffin type tank,what size to get?

[mikell]

I have a tank with no markings on at present about 2.5 ft x 2.5ft x 2ft that feeds the house.

Want to get a coffin type for the eves ,but got one that measured 61 x 18 x 18 (seemed about right)but when i got it up there it is absolutely massive!

I'd guess half this size would do but what capacity would I require? Is 25 gallon the smallest?

We are a family of five in a 3 bed house. Any help please gents.

Thanks in advance.

 

[Bahco]

Will THIS be ok

 

[mikell]

thanks,
that looks like my old one,but mabye a bit smaller ,will pop up and measure it properly tommorow.the tank needs to be low and slender, but the one I got seems almost industrial size! I could use it myself as a plastic sleeping bag,the ballcock is also about a size five caseball size( ok a bit smaller,but still big) so Im guessing that there is standard house sizes you plumbers use up to a certain litreage,before we hit the BIG sizes, any ideas of standard domestic or is there no such thing?

 

[mikell]

written on the new big long tank it says- `500 hr type tested feed and expansion tank` what is 500 ?

the old one just has measurements on it 30 x 24x23.

500 hr ? any ideas