Service manual
SECTION 6: RADIANT TUBE AND TAILPIPE
19
6.5.4 To Check Performance Criteria
Compare the results to Page 17, Table 4 and Page
18, Table for the burner model to ensure that the
resulting tailpipe lengths maintain intended operating
characteristic.
6.5.5 Damper Couplings
Damper couplings are needed:
• In any tailpipe branch that carries less flow units
than other tailpipe branches connected to the
same pump
• In unsymmetrical layouts with branches having
the same number of flow units, the damper cou-
pling is placed in every branch except for the
longest branch.
The purpose of the damper coupling is to adjust the
end vent vacuum down to the desired level. These
are to be placed in the tailpipe section and not the
radiant branch. The recommended location is before
the first tee fitting or 10'-40' from the end of the radi-
ant pipe. See Page 20, Figure 17; Page 23, Figure
21, Page 24, Figure 25, and Page 25, Figure 26 for
placement examples.
Total system tailpipe
= Tailpipe ft/flow unit
Total flow units