Technical Sheet

COLD
HOT
MIX
32
60
80
100
120
140
160
Kills bacteria instantly
Kills 90% of bacteria in 2 minutes
Kills 90% of bacteria in 2 hours
Optimum temperature
for growth of bacteria
Surviving bacteria inactive
521 “A” model,
NPT male union
Inlet port check valve
detail for 521 “AC”
models NPT male union
Inlet port check valve
detail for 521 “AC”
models sweat union
Item Description
Item
quantity
per valve
1/2 inch 3/4 inch 1 inch
NPT
521400A, AC
Sweat
521409A, AC
NPT
521500A, AC
Sweat
521509A, AC
521519A, AC
NPT
521600A, AC
Sweat
521609A, AC
521619A, AC
Union washer 3 R50055
Union nut 1" 3 R61008
Male tailpieces 3 R31981 NA10002 31901A
NA10003
(2 only – “519”)
59817A*
59834A*
(2 only – “619”)
Inlet male tailpiece
with check valve –
“AC” models only
2 59893A 59904A 59840A 59905A 59894A 59906A
Outlet tailpiece –
“AC” models only
1 R31981 NA10002 31901A NA10003 59817A* 59834A*
Outlet adapter with
temperature gauge
1 — — — NA10056 — NA10058
Replacement
temperature gauge
1 — — — 688003A — 688003A
*Tailpiece fitting with integral union nut. 1" NPT and Sweat models require only two separate 1" union nuts (R61008).
Construction details
Anti-scale materials
The material used in the construction of the thermostatic mixing valve
eliminates the problem of jamming caused by lime deposits. All the
working parts such as shutter, seats and slide guides are made of a
special anti-scale material, with a low friction coefficient, guaranteeing
that the performance will be maintained over the long term.
Temperature setting and locking
The control knob permits temperature setting between minimum and
maximum in one turn (360°). It also has a tamper-proof system to lock
the temperature at the set value.
Operating principle
The controlling element of the three-way thermostatic mixing valve is
a thermostatic sensor fully immersed in the mixed water outlet tube
which, as it expands or contracts, continuously establishes the correct
proportion of hot and cold water entering the valve. The regulation of
these flows is by means of a piston sliding in a cylinder between the
hot and cold water passages. Even when there are pressure drops due
to the drawing off of hot or cold water for other uses, or variations in
the incoming temperature, the thermostatic mixing valve automatically
regulates the water flow to obtain the required temperature.
Thermal disinfection
The diagram shows the behaviour of the bacteria Legionella
Pneumophila when the temperature conditions of the water in which it
is containedvary.
In order to ensure proper thermal “disinfection”, the values must not be
below 140°F.