1″BSP Immersion Heater

1″BSP Immersion Heater


The littlest on my list, and the smallest I’ve ever sold, a 1″BSP Immersion Heater naturally has limitations, as size does indeed matter, Matron!

G / R
Threadpitch Major
  Tapping drill  
      R 95% G 80%
(in) (in−1) (mm) (in) (mm) (in) (mm) (in) (mm) (mm) (mm)
1″BSP 11 2.309 1.309 33.249 1.1926 30.291 0.4091 10.4 30.4 30.9

With a circumference of  104 mm and a diameter of 33mm, it is only possible to fit 2 x 8mm U bent elements and 1 stat pocket

onto the screwplug, and thus it would have to be a Single Phase immersion heater.

  • Available at any kW loading from 500w up to 6kW.
  • 1″BSP only available in brass.
  • Available with 1 thermowell at 7, 11 or 18″ for thermostats / cutouts.
  • 2 M25 cable entry glands as an option.
  • Available with no thermowell if specified by the client. If you don’t need it, omit it from the build, as it is an unecessary weak point.

Within the limitations listed above, it is best we have a conversation about your 1″BSP Immersion Heater needs, so call Jamie on 01827 215684 to discuss, in order to co-design the best heater to suit your needs. Your maximum immersed length will be key, with only 2 looped elements to play with, so get your tape measure out, keep it stiff, and stick it through your hole to see how long we can go with those elements. And don’t have a stat pocket unless you really need one. There are benefits to having your heater made bespoke as it allows you to precisely hit your requirements, rather than taking a “Best Fit” off the shelf.

Plan B.

Should you decide that these limitations are too restrictive, there is always the rather drastic & expensive option of changing your 1″BSP fittings for a more luxuriant, industrial standard 2.25″BSP entry fitting. This will require you to know a friendly fabricator to lop off your 1″ fitting, cut a 70mm hole in the vessel, then weld one of these lumps to your vessel.

…which can be found here in SS316 – https://www.ebay.co.uk/itm/183896119193

…or here in Carbon or Mild Steel – and even cheaper here if you don’t mind a funny shape.

We used to stock stuff like this, but since the world and it’s prices went mad, it’s just not worth the bother anymore, so ebay is your friend.

Call Jamie on 01827 215684 to discuss further.


There are no reviews yet.

Be the first to review “1″BSP Immersion Heater”