Calculating Radiator Pipe Centres & Maximum Width of Radiators

We always advise you to wait for your cast iron radiators to be onsite before working out pipe work and pipe centres widths. This is because cast iron is not an exact product and because each radiator is hand assembled there will always be slight discrepancies as indicated on each radiator page in the lengths of same style & size radiators.

However, we appreciate that occasionally some prep work may need to be carried out prior to your order arriving onsite and that approximate pipe centre measurements may be required for first fix purposes.

In this instance, please refer to the technical drawing/specification document, saved as a PDF on each individual valve type, for the measurement from the thread on the valve tail to the centre point of the valve, and add this to the length of your radiator to work out your approximate pipe centre measurement.

For example, if fitting one of our Kenilworth Thermostatic Valve Sets, which has a measurement of 45mm from thread on the valve tail to the centre point of the valve, to a 10 section, Traditional Victorian radiator at 650mm wide, the approximate pipe centre measurement would be 740mm.

For the approximate measurement off the skirting board or wall if no skirting is used to the pipe centre we suggest half the depth of the cast iron radiator + 10mm as a minimum.

For the approximate ‘outside valve to outside valve measurement’ (the minimum measurement to be able to operate the valves freely) you should add approx 150mm/6.0” to the length indicated for each radiator in the Specification tab, however this measurement will vary depending on the valve that is fitted - this measurement should be used if fitting the radiator and valves into an area where there may be a width restriction.