Oil tank and pipeline flow question

[byronelvis]

When installing an 1200 litre oil tank and 10mm pipeline into a dwelling,is there a head height of oil tank / length of oil line equation that should be adhered to like we have when pipe sizing with gas?
The boiler has been firing fine when the tank was fuller.
Now although the bottom of the tank is level with the level at which the oil Line enters the house, it drops to ground level , runs about 10 metres , with 4 slow/smooth 90' bends then rises and enters the house and boiler.
There is a decentish flow of oil when undoing the nut on the fire break valve just outside the boiler wall but is really poor at the boiler itself .I've also checked for any blockages on this last section just a few more meters away.
This flow was a lot stronger flow when installed but there was more fuel in the tank so is obviously something to do with the head of oil weight .
We ( myself and the builder who installed this ) has asked me to look into this as he wants relocate the tank, still further away than the current location , but higher. Will he also need larger bore pipe, or is 10mm
standard practice ?

 

[dcawkwell]

No you can go large distances and 10mm pipe will be plenty
to supply a standard house burner.
Making the pipe larger will only make it harder for the oil
pump to lift fuel if there is any height to lift.

If you consult your oil boiler manual that came with the boiler
it will give guidance on this.

I hope you had the oil installation signed off by a registered oftec
engineer.

 

[Boilerman2]

When re-locating the oil tank bear in mind the requirement for any joints underground to be installed within an inspection chamber No Buried joints allowed!!