25
STS INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
INSTALLATION
DC-1468
Optional condensate
return piping from
dispersion unit*
Air vent tube
H2 (see Table
24-1)
Strainers
(by installer)
Steam outlet
Install level
Install level
Over
fl ow
line
Traps
If run is over 10' (3 m), increase pipe to
1¼" (DN32)
1" (25 mm) air gap
Open fl oor drain.
See fi rst note below
Unions (by installer)
Water seal line MUST be below
drain valve to ensure humidifi er
drains correctly
6"
(152 mm)
minimum
Water supply line (see Table 25-1); water
pressure range 25 to 80 psi (172 to 582 kPa)
3/4" (DN20)
minimum condensate drain piping
rated for 212 °F (100 °C)*
Condensate return
to nonpressurized
system, by gravity
only
12"
(305 mm)
minimum
drop to
traps
Vacuum breakers (by installer)
Notes:
• Offset hu
mid i fi er from fl oor drain to prevent fl ash steam from rising into the hu mid i fi er.
•
Locate air gap only in spaces with adequate temperature and air movement to absorb fl ash steam; otherwise, condensation may form on nearby
surfaces. Refer to governing codes for drain pipe size and maximum discharge water temperature.
•
Water supply inlet is more than 1" (25 mm) above skim/overfl ow port, eliminating the pos si bil i ty of backfl ow or si phon ing from tank. No additional
backfl ow prevention is required; however, governing codes prevail.
• Damage caused by chloride corrosion is not covered by your DriSteem warranty.
• Dashed lines indicate provided by installer.
H1 (see
Table
24-1)
3/4" pipe thread (DN20)
dispersion unit condensate
return inlet*
Drain, skim,
overfl ow piping
rated for 212 °F
(100 °C)
(see sizes in
Table 25-1)
From
steam
source
Pitch 1/8"/ft
(1%) toward drain
If water piping to humidifi er is nonmetallic, we recommend a
2" (50 mm) metallic water seal or loop in the supply line to
isolate steam during maintenance
Strainer (by installer)
mc_010411_1550-di
Manual SST drain valve (electric drain valve
available for end-of-season drain option)
Table 25-1:
STS connection sizes
Description
Connection size
Water makeup (fi ll)
1/4" pipe thread (DN8), all STS models
Drain
3/4" (DN20) for STS models 25 through 100
1" (DN25) for STS models 200 through 800
Steam outlet
Varies with capacity and dispersion type; see Table 27-1
Condensate return
3/4" pipe thread (DN20)
Pressurized steam supply inlet
and return outlet
See sizes in Tables 5-1 and 5-2
mc_010411_1555
* Condensate return
piping is not needed for
Ultra-sorb® Model XV
dispersion unit, which
returns pressurized
condensate to the boiler.
See the Ultra-sorb Model
XV Installation Guide
for condensate piping
requirements.
Piping: RO/DI water option, two heat exchangers
FIGURE 25-1: FIELD PIPING OVERVIEW FOR STS MODEL 800 WITH RO/DI WATER OPTION
