Download DriSteem Vaporstream Specifications

Piping a steam injection system
Pressurized steam piping guidelines
• Size piping in accordance with ASHRAE recommendations.
• The humidifier’s steam supply should be taken off the top of the
steam main (not the side or bottom) to ensure the driest steam.
The main should be dripped and trapped (in accordance with
ASHRAE recommendations).
• The humidifier steam trap(s) must drain by gravity to the return
main having little or no back pressure. If condensate cannot drain
by gravity, then it must be elevated to the return main (see the
next page for instructions).
• If steam pressure is < 15 psi (103.4 kPa), use float and
thermostatic (F&T) traps for the humidifier.
• If steam pressure is >15 psi (103.4 kPa), use inverted bucket traps
for the humidifier.
• If lifting condensate, use an inverted bucket trap. See drawings
and instructions on the next page.
• Condensate from unavoidable heat loss in the distribution
system must be removed promptly to eliminate water hammer,
Figure 66-1:
Piping from boiler to humidifier
Take off branch lines from the top of the
steam main, preferably at a 45° angle,
although vertical 90° connections are
acceptable
45°
Insulate piping
End of main
steam trap
by installer
Condensate return
Blowdown valve
by installer
Automatic
warm-up:
28" (711 mm) minimum.
Supervised warm-up:
1.5 × pipe diameter,
8" (203 mm) minimum.
If pipe is 4" (DN100)
or larger, size drip for
50% of the condensate
load at start-up. If pipe
is less than 4" (DN100),
size drip for 25% of
the condensate load at
start-up.
"
in 1⁄4 )
ma (0.2%
h
c
Pit r 10'
pe
Pit
c
per h hum
fro 10' idifi
m
(0 e
les main .4%) r bran
s th to if ch
an hum dist 1/2
10' id anc "
(3. ifier e
3 m is
)
Bra
nch
t
ra
m if d p r
gre ain t istan ecom
ate o h ce f me
r th um rom nde
an idifi
d
10' er
(3.3 is
m)
To humidifier.
Inlet strainer must
be within 3' (1 m)
of humidifier
Humidifier isolation valve
Insulate piping
Branch
steam
trap
by installer
Condensate return
Blowdown valve by installer
Page 66 • DRI-STEEM Design Guide
Piping same size as
humidifier inlet strainer
12" (305 mm) minimum
4" (100 mm) minimum