Product Overview

Kv = 2.6
0.1
10
0.023
0.23
0.046
0.069
0.02 0.05 0.2 0.5
0.115
2.3
0.46
0.69
1.15
20 50
∆p (ft of head)
G (l/min) (
gpm
)
23
4.6
6.9
11.5
46
0.01
0.1
0.02
0.03
0.05
1
0.2
0.3
0.5
(psi) (bar)
10
2
3
5
20
1 0
.
1
0
.2
0.5 0
.05
10
2 5 2
0
0.001
0.01
0.002
0.003
0.005
0.1
0.02
0.03
0.05
1.0
0.2
0.3
0.5
Cv = 3.0
9.2
0.092
0.92
0.04
0.4
4
0.004
0.04
0.4
50
115
161
50
70
2.0
5.0
190
70
100 140
M
I
N
M
A
X
7
1
2
3
Index Point
Flow curve
Use
Caleffi MixCal
™
521 series thermostatic mixing valves are designed to be
installed at the hot water heater. The 521 series valve cannot be used
for tempering water temperature at fixtures as a point-of-use valve. They
are not designed to provide scald protection or chill protection service.
They should not be used where ASSE 1070 devices are required.
Wherever a scald protection feature is required, Caleffi 5213 series high
performance mixing valves need to be installed. For safety reasons, it is
advisable to limit the maximum mixed water temperature to 120°F.
Instantaneous production of hot water
Caleffi MixCal
™
521 series thermostatic mixing valves should not be
used in conjunction with boilers giving instantaneous production of
domestic hot water. This could compromise the correct operation of
the boiler itself.
Radiant heating systems
Caleffi MixCal
™
521 series thermostatic mixing valves can also be used
for regulating the flow temperature in hydronic and radiant heating
systems, to which it assures a constant and accurate control with ease
of installation.
Temperature stability
The diagram shows the stability of the temperature of the mixed water
on variation of the temperature of the stored water. Stable mixed
temperature during water heater recovery.
Installation
Before installing a Caleffi MixCal
™
521 series three-way thermostatic
mixing valve, the system must be inspected to ensure that its operating
conditions are within the range of the mixing valve, checking, for
example, the supply temperature, supply pressure, etc.
Systems where the 521 series thermostatic mixing valve will be installed
must be drained and cleaned out to remove any dirt or debris which may
have accumulated during installation.
The installation of appropriately sized filters at the inlet from the main
water supply is always advisable.
Caleffi MixCal
™
521 series thermostatic mixing valves must be installed
by qualified personnel in accordance with the diagrams in this brochure,
taking into account all current applicable standards.
Caleffi MixCal
™
521 series thermostatic mixing valves can be installed in
any position, either vertical or horizontal, or upside down.
The following are shown on the thermostatic mixing valve body:
- Hot water inlet, color red and marked “HOT”.
- Cold water inlet, color blue and marked “COLD”.
- Mixed water outlet, marked “MIX”.
Check valves
In order to prevent undesirable backsiphonage, check valves should be
installed in systems with thermostatic mixing valves. As a convenience
for easier installations, the Caleffi MixCal
™
521 “AC” series thermostatic
mixing valves include integral check valves in the hot and cold inlet
ports.
Commissioning
The Caleffi MixCal
™
521 series thermostatic mixing valve must be
commissioned in accordance with current standards by qualified
personnel using temperature measuring equipment. Caleffi 521419A,
521519A and 521619A with integral outlet port temperature gauges
provide a time-saving temperature setting process to get close to the
desired temperature. Use of a digital thermometer is recommended
for determing the final setting of the mixed water temperature. Note:
For models purchased without the outlet temperature gauge, the
temperature gauge adapter with temperature gauge can be separately
purchased and field installed, code NA10328 for 1/2" models, code
NA10056 for 3/4" models or code NA10058 for 1" models.
Temperature adjustment
The temperature is set to the required value by means of the knob with
the graduated scale, on the top of the valve.
Locking the setting
Position the handle to the number
required with respect to the index
point. Unscrew the head screw, pull
off the handle and reposition it so that
the handle fits into the internal slot of
the knob. Tighten the headscrew.
Pos. Min. 1 2 3 4 5 6 7 Max.
T (°F) 81 90 100 111 120 127 136 145 152
T (°C) 27 32 38 44 49 53 58 63 67
with: T
HOT
= 155°F (68°C), with: T
cold
= 55°F (13°C), P = 43 psi (13 bar)
Flow should never exceed standards for pipe size and materials.