Powers HydroGuard e427 Series Technical Instructions

DESCRIPTION
e428
The Series e427 and e428 HydroGuard valves automatically
mix hot and cold water to deliver blended water at any desired
temperature within a specified range. The assembly contains
an advanced thermal actuators which maintains the selected
water temperature within rigid tolerances despite temperature
and pressure fluctuations in the water supply.
Construction features include a built-in shutoff valve for delivery
water, a poppet type mixing valve, a concealed adjustment for
raising and lowering the temperature range, and corrosion
resistant parts.
The Series e427/e428 HydroGuard is simply constructed. All
parts are accessible from the front, to facilitate cleaning and
maintenance.
The Series e427/e428 HydroGuard is preferred for a wide variety
of applications because of its accuracy, reliability, and economy
of water and energy. It is chiefly used in showers, baths, hospital
hydrotherapy and residential areas, where precise, consistent
water temperature is required.

SPECIFICATIONS

Maximum Hot Water Supply Temp.
Minimum Hot Water Supply Temp. . . . 10°F (6°C) above set point
Maximum Operating Pressure . . . . . . . . . . . . . . 125 psi (861 kPa)
Temperature Range (standard)
(low temperature) . . . . . . . . . . . . . . . . . . . . . 60-100°F (16–38°C)
(high temperature) . . . . . . . . . . . . . . . . . . . 100-160°F (38–71°C)
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1⁄2" NPT
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 gpm (0.90 l /s)
Minimum Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 gpm
Maximum Static Pressure . . . . . . . . . . . . . . . . . 125 psi (861 kPa)
Finish . . . . . . . . . Chrome Plated on e428, Rough Bronze on e427
Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ASSE 1016
Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . CSA B125 Certified
Shipping Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 lbs.
e427
. . . . . . . . . . . . . 190°F (88°C)
. . . . . . . . . . . 90-110°F (32–43°C)
TECHNICAL INSTRUCTIONS
Thermostatic Mixing Valves
SAFETY AND PERFORMANCE GUIDELINES
Adherence to these guidelines and recommendations promotes
safe product use and ensures proper valve performance.
1. Thermostatic water mixing valves are control devices which must
be cleaned and maintained on a regular basis. Powers specifies
periodic maintenance at least once a year or immediately after
any changes are made to the plumbing system. Although annual
cleaning is recommended, frequency of cleaning depends on
quality of local water conditions. Refer to Preventive
Maintenance on page 2 for recommended cleaning procedure.
2. Locate the valve as close as possible to the fixture being
supplied to avoid waste of energy and water.

OPERATION

Hot and cold water supplies enter the e427/e428 HydroGuard
through their respective inlet ports. Hot and cold water mix in the
chamber containing the cartridge and thermal actuator assemblies.
The resulting mixture flows across the thermostatic motor, and the
motor positions the valve assembly to maintain the desired delivery
water temperature. Delivery water temperature can be varied by
turning the adjustment handle. Turning the handle counterclock-
wise raises the temperature of the delivery water, and turning the
handle clockwise lowers the temperature. Turning the handle com-
pletely clockwise seats the shut off valve and completely stops
the flow. At the same time the hot water disc seats, preventing
crossflow of the water supplies. Valve (without checkstops) does
not prevent crossflow if left in open position and a downstream
shutoff valve is used. If the temperature of the mixture is higher
than the temperature setting, the advanced thermal actuator
expands and forces the valve assembly to move toward the hot
water seat. The reverse occurs when the mixture temperature is
lower than the temperature setting. A change in water temperature
of either hot or cold water supply will cause the advanced thermal
actuator to reposition the valve assembly to maintain the desired
delivery temperature.

PREVENTIVE MAINTENANCE

NOTE: Before servicing checkstops or piping, always turn
off the upstream water supply.
EVERY 12 MONTHS:
• Open up the checkstops and check for free movement of
the poppet. To access the checkstops, remove the handle
assembly and trim plate.
• Before servicing the valve, turn off the water supply upstream
OR close the checkstops. To close the checkstops, turn the
adjustment screw fully clockwise on each checkstop.
• Remove the valve bonnet and rinse all grit and impurities from
the cartridges.
• Winterize valves that are used outdoors. Remove and store
the internal components and drain all water from the valve.
EVERY 3 MONTHS:
• Every three months, check the maximum temperature setting.
HydroGuard ® e427/e428
Form TI e427 v2