Clang in radiator section

Dave Stockhoff

I posted a few days ago about a banging in my 2-pipe/air vent system. I've traced the noise to a single section of a radiator in the middle of a bank of 5. It happens that that middle section is lukewarm when the others are hot, although it doesn't stop downstream sections from heating. I've concluded that the noise comes from differential warming and thermal expansion/contraction of that section, especially where the sections have contact at the top. So more questions arise:

(1) Is the section clogged, and if so how, why, and with what? is it a bad nipple?

(2) How can I stop the noise without disassembling the section? Would tightening the threaded rods at the top help, make it worse, or risk damaging the section? The sections seem a bit farther apart at the top where the rods are, so maybe they are not tight enough.

(3) What's involved in removing/replacing an air vent? Do they just twist off?

Thanks!

Timco

Vents just thread off...1/8 NPT usually. If the rods are loose, and the sections are not alligned, you can try tightening the rods. Can't imagine steam would make loose bits of nipple clang....likely just the exp / cont of the loosening nipple.

Tim