Hale RSD - Manual (Page 24)

❑ Accessories
24 Section 2a: Accessories
Hale Products, Inc., Nov. 2005, Rev-A
The optional TRV protects the pump from overheating. It is attached to the
discharge piping either by flange mounting or 1-1/4” NPT threaded connec-
tion (38 mm for Model TRVM). (See Figure 2a-3: “Thermal Relief Valve,
TRV,” on page 23.)
The valve monitors the temperature of the water in the pump. When tem-
peratures exceed 120° F (49° C), the valve automatically opens. Depend-
ing on the installation, a small amount of water either discharges to the
ground or into the water tank allowing cooler water to enter. After the tem-
perature returns to a safe level, the valve closes.
TRV-L Kit
The TRV-L kit includes a chrome panel placard with a warning light, a light
test button, and a pre-assembled wire harness. The RED light illuminates
when the TRV is open and discharging water. Also see Figure 2a-3: “Ther-
mal Relief Valve, TRV” on page 23.
An optional buzzer, mounted on the operator panel, provides an audible
warning.
2A.4 PRIMING SYSTEMS
Priming pumps are used to evacuate air in the suction hose and pump. The
vacuum created allows atmospheric pressure to push water from the static
source through the suction hose and into the pump.
Hale pumps use Rotary Vane Positive Displacement pumps for priming.
(See Figure 2a-4: “Rotary Vane and ESP Priming Pumps,” on page 25.)
The priming pump has a rotor mounted off-center (eccentric) to the pump
body housing. The rotor vanes slide in grooves and are held against the
body housing by centrifugal force.
As a vane turns toward the discharge, it recedes into the rotor compressing
the air. As the rotor continues past the discharge, the vane advances out-
ward from the groove and against the body housing. During this cycle, the
space between the rotor and housing case fills with air. The vanes, acting
as wipers, force air out of the discharge, creating a vacuum in the main
pump allowing atmospheric pressure to push water into the hose and suc-
tion side of the pump.
The Hale ESP series priming pump is an environmentally friendly primer
that does not require a separate lubricant reservoir. The vanes and pump
body are self-lubricating for maintenance free operation. (See Figure 2a-4:
“Rotary Vane and ESP Priming Pumps,” on page 25.)