Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Which Hoffman 17C cage unit vents faster: Tunstall or B&J?

Just curious--I'm working on fine tuning my system and have had some luck with replacing a few stock Hoffman 17C capsules with B&J units, based on the data in Gerry Gill's balancing book. That book doesn't include any data on the equivalent Tunstall replacement cage--anyone know which is faster or if they're about the same?


  • I would think the capacity is dependent on the size of the orifice under the new capsule, and with either make, it would be the same.--NBC
  • Waterbury Steam
    Waterbury Steam Member Posts: 53
    Maybe I should just order one of the Tunstalls and give it a try. I know the B&J is a lot faster than the stock Hoffman.
  • Silkey
    Silkey Member Posts: 18
    I am replacing what looks to be original 1/2" steam traps with new Hoffman 17c traps. (Thats what the repair man used when one leaked last winter). The originals have an S inside a circle with a wishbone or v underneath.
    My question is if I should install new Bar and Jones Cage units when installing the new traps. I have not yet bothered to calculate many things...how much air in the main line, size of radiators....

    2 story house, 1600sq ft, about 22' x 36' each floor, 8 radiators, 2 main lines: 1 is about half the length of the other.