20
STS INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
WATER SUPPLY PIPING
All STS humidifi er models have a 1" (25 mm) internal air gap to prevent back
siphoning into a potable water system. However, some governing codes may
require additional protection such as a vacuum breaker or backfl ow preventer.
The supply water pressure range must be 25 to 80 psi (172 to 552 kPa).
TAP/SOFTENED WATER STS
Water supply assembly includes a strainer, needle valve, and fi ll solenoid —
1/4" pipe thread (DN8) connection. European models are provided with a
3/8" pipe thread (DN10) connection. Since the primary component of the
water supply assembly is a solenoid valve, there may be noise issues that
surface during a fi ll cycle.
During a fi ll cycle, the supply water drops the water temperature in the tank
and may collapse the steam, which can cause a low rolling sound. To diminish
this, adjust the needle valve to decrease the water fi ll rate and/or use hot
supply water.
In cases where water hammer occurs when the fi ll solenoid closes, a shock
arrester is recommended. Reducing the supply water pressure (minimum
25 psi [172 kPa]) or using fl exible tubing (rated 212 °F [100 °C], minimum
continuous operating temperature) may diminish the noise, but installing a
shock arrester is the best solution.
The minimum water conductivity for the probe-type water level control system to
work is 30 μS/cm.
INSTALLATION
Piping: Fill
