Hydro-Guard® Freeze Protection Overview
• Frost depth of zero to 16 inches: Hydro-Guard Standard Unit (HG1) with atmospheric discharge. Valve bury depth of 16”. Built in sampling.
• Frost
depth of zero to 18 inches: Hydro-Guard Basic Unit (HG1 Basic) with
atmospheric discharge. Valve bury depth of 18”. No built in sampling.
•
Frost depth of zero to 30 inches: Hydro-Guard Vertical Units (HG5Vac, HG5-RP2
and HG5Air) and Hydro-Guard Direct Discharge Unit (HG2 and HG2-Air). These devices
offer directed discharge. The HG5Vac employs a pressure
vacuum breaker for backflow prevention and is hard-piped to a sanitary
sewer, storm sewer etc. The HG5Air offers an air gap for backflow prevention
and discharges into a receiver pipe (supplied by others). These two
models offer integrated programmers with a 10-flush per day capability. The HG5-RP2 and HG2 are built with an RPZ backflow preventer. Both are programmed via an interactive programmer and powered by
a 9-volt alkaline battery good for approximately six months to one year of daily flushing.
Each of these Units offers built-in sampling. The
freeze protection used on these Units is a self-actuating, mechanical
thermal control valve (TCV). The valve senses the water temperature
within the device and will, at a predetermined temperature, open to
allow a trickle of water to flow through the main valve in order to
prevent freezing. Once warmer water has been introduced to the Unit
the valve will close. Max flow rate of the TCV is 1gpm and is achieved
at five degrees below the preset temperature. Most Units in the US
are calibrated to 40F with max flow at 35F. Some Canadian Units as
well some as some Units within mountainous regions of the US
are calibrated to open at 35F with max flow at 30F. Once the 1gpm is
reached the main valve within the Units opens and immediately introduces
warmer water from below frost depth. This shuts off the thermal control
valve. The TCV’s operation does not interfere with programmed
flushing schedules.
• Frost depth of 24 to 84 inches (Custom lengths available): Hydro-Guard
Longneck Units (HG3 and HG4). The Longneck Standard Unit (HG3) offers
atmospheric discharge and an air gap for backflow prevention. The LongNeck
Sub-surface Discharge Unit (HG4) discharges into a receiver pipe (by
others) and employs an air gap for backflow prevention. These Units
offer integrated freeze protection by virtue of their design. Each
of these is designed to bring the valve and electrical components below
the local frost depth. The working components
are assembled on a cam-lock system that allows the end user to conveniently
retrieve the mechanicals when battery replacement or maintenance is
required. These Units are powered by the 9-volt alkaline battery and
programmed via a hand-held programmer. The multi-flush per day
programming options are particularly important to the HG3 as discharge
volumes can be managed effectively (i.e. in a freezing scenario ice
build up can be prevented by breaking the flush duration up into smaller
packages). A ten minute daily discharge can be executed through two
three-minute flushes and a final four minute flush each executed an
hour apart. Built in sampling is available as an upgrade, otherwise a brief
manual flush allows the collection of the sample from the discharge
point.