Why were cast rads plumbed top and bottom for flo and return

[Glenbirnie]

Hi,

I have been refurbing some original cast rads which i will be starting to fit shortly.

All the rads I have came out a working sytem from a fire station and the flow and return where plumbed into one lower connection and one upper connection why was this?

Can I plumb them in the modern way with valve and lockshield at the bottom?

Thanks

 

[ALEC1]

Yes, early systems were gravity from coal fired boilers so the therm syphonic effect is enhanced with TBOE (top bottom opposite ends) which still enhanes radiator performance. This is also why good radiators have predetermined flow tappings...

 

[SandyLyon]

Most we're fitted on a single pipe system, sometimes on gravity circulation as well.

The connections would have been 3/4" or 1" TBOE, if you are using on a 2 pipe pumped system, you can bush the trappings and use either 15 or 22mm valves, depending on the output of the radiator.

Yes, you can use BOE wheel or TRV and LSV.

 

[Glenbirnie]

So would I be better putting them back in the TBOE way, I have a modern gas boiler system?

I was concerned about having a hot copper pipe going from floor to top of rad, I have young kids, but the rad will get hot anyway I supposse.

On a modern steel rad then are you relying on the cold water in the rad falling and being pushed out?

Im using old style TRV's

Thanks

 

[Agile]

It makes little difference on a pumped system.

But many c/i/ rads need a blockage in the bottom centre to ensure adequate flow.

Tony

 

[doitall]

It makes little difference on a pumped system.

But many c/i/ rads need a blockage in the bottom centre to ensure adequate flow.

Tony

Who told you that rubbish Tony

Unless the OP has the kit to change the tails and bushes I suggest leaving them TBOE.

 

[bab]

Id recomend bottom tappings either side. top and bottom ethier end can cause a cool bottom corner below the top entry valve if flow is inadequate and also leaves a vunerable pipe on top feed

 

[CBF]

& make sure you bolt them to the wall you don't want them falling on the kids, also make sure you fit some kind of magnetic filter on the return to the boiler you wouldn't believe the amount of crap you will get out of these, i've got one customer on their third boiler in ten years & it's all down to the crap in the rads (even though it's been powerflushed twice) & the fact they don't clean the filter of course

 

[sherbert]

It makes little difference on a pumped system.

But many c/i/ rads need a blockage in the bottom centre to ensure adequate flow.

Tony

Where did you make this crap up from

Have never made up cast rads and been told to put a blockage in the bottom ........ Be honest have you ever made up a cast iron rad

The correct answer has been said ......... Goes back to days of old when we had gravity 1 pipe systems

 

[gaswizzard]

But many c/i/ rads need a blockage in the bottom centre to ensure adequate flow.

Made many cast iron rads up over the years , are you saying some sort of a restrictor should of been fitted between the sections? , are you also saying the 'restrictor' was missing? , can't say i've ever noticed a restrictor when looking through the bottom tappings. , was there a section that differed from the standard one's? (me thinks not )

These 'assumptions' do you no favours whatsover , you forget there are guys on here with far more experience.

Not being funny Tony but BS needs to be addressed..

 

[Biggles..]

Totally agree.
Used to take hours splitting down the rads to add that invisible restrictor!

 

[newbuildinstaller]

It makes little difference on a pumped system.

But many c/i/ rads need a blockage in the bottom centre to ensure adequate flow.

Tony

Who told you that rubbish Tony

.

The guy who sold him the blocked rad!!!

 

[Glenbirnie]

I have a magna clean that was in the house and hadnt been here long, I was thinking of having two. Is this ok?

I know they will produce a lot of residue into the system, hopefully no more dolly pegs though! I found a 'preserved' original dolly peg stuck in one of the rads!

 

[Nige F]

that was the restrictor

 

[ALEC1]

A few modern immitations of CI radiators do have baffles, to behave like a TBOE radiatior..Zehnder, for example...that baffle is only two sections from one end, and the bleed valve is the opposite end. The radiator has to have the flow opposite the bleed valve..