Caleffi 5231 User Manual

Thermostatic mixing valves,
low-lead, high-flow

5231 series

CALEFFI

ACCREDITED

ISO 9001 FM 21654

ISO 9001 No. 0003

01256/14 NA

Function

The thermostatic mixing valve is used in systems producing domestic
hot water or in radiant heating systems. Its function is to maintain the
temperature of the mixed water supplied to the user at a constant set
value when there are variations in the supply pressure and temperature
of the incoming hot and cold water or in the flow rate.

The 5231 series thermostatic mixing valves are ASSE 1017 approved for
point of distribution and are designed specifically for systems requiring
high flow rates and precise, stable temperature control.

ASSE 1017

Product Range

Code 5231_0A Thermostatic mixing valve (ASSE 1017) with threaded connections.........................................................sizes 1”, 1-1/4”, 1-1/2”, 2” union NPT male

Code 5231_8A Thermostatic mixing valve (ASSE 1017) with sweat connections................................................................... sizes 1”, 1-1/4”. 1-1/2", 2" union sweat

Code 523177A Thermostatic mixing valve (ASSE 1017) with sweat connections and outlet temperature gauge..................................... sizes 1-1/4” union sweat

Technical specification

Materials: - Body: Low-lead brass

- Shutter: PPSG40

- Springs: Stainless steel

- Seals: EPDM

Suitable fluds: Water, glycol solutions
Maximum percentage of glycol: 30% glycol solution
Setting range:
See table on page 3
Temperature stability: ± 3°F (± 2°C)
Max working pressure (static): 200 psi (14 bar)
Max operating differential pressure: 70 psi (5 bar)
Hot water inlet temperature range: 120 – 195°F (49 – 91°C)
Cold water inlet temperature range: 39 – 80°F (3.9 – 26.6°C)
Mixed temperature range: 95 – 150°F (35 – 66°C)
Maximum inlet pressure ratio (H/C or C/H): 2:1
Minimum temperature difference between hot water inlet
and mixed water outlet for optimum performance: 20°F (11°C)
Maximum water hardness: 10 grains
Certifications:

1. cUPC Listed to ASSE 1017/CSA B125.3. Reduction of
Lead in Drinking Water Act Compliant: 0.25% Max.
weighted average lead content. Reduction of Lead in
Drinking Water Act Certifed by IAPMO R&T.

2. Meets requirements of ANSI/NSF 372-2011.

Dimensions

C

B B

F

A

D

HC

A

E

Sweat version

110

130

90

D

F

70

E

50

30

150

170

190

210

A

A

Code A B C D E F Wt (lb)

523160A 1" NPT 4" 8" 7 5/8" 4 3/16" 3 3/8" 7.0

523168A 1" SWT 3 5/16" 6 5/8" 7" 3 1/2" 3 3/8" 7.0

523170A 1 1/4" NPT 4 1/8" 8 1/4" 7 3/4" 4 5/16" 3 3/8" 7.1

523177A 1 1/4" SWT 3 3/8" 6 3/4" 7 5/8" 4 1/8" 3 3/8" 8.5

523178A 1 1/4" SWT 3 3/8" 6 3/4" 7" 3 1/2" 3 3/8" 7.1

523180A 1 1/2" NPT 5 1/8" 10

523188A 1 1/2" SWT 4 1/16" 8 1/8" 8 1/8" 4 3/8" 3 3/4" 17

523190A 2" NPT 5 1/8" 10

523198A 2" SWT 4 5/16" 8 5/8" 8 5/8" 4 7/8" 3 3/4" 18

1/4" 9 3/16" 5 7/16" 3 3/4" 17

1/4" 9 1/2" 5 3/4" 3 3/4" 18

A

“Legionella” - Scalding risk

Principle of Operation

In systems producing domestic hot water
with storage, in order to avoid the dangerous
bacteria known as ”Legionella”, the hot
water must be stored at a temperature of at
least 140°F. At this temperature it is certain
that the growth of the bacteria causing this
infection will be totally eliminated. However,
at this temperature the water cannot be
used directly, as it may cause scalding. For
example, at 130°F, partial burning takes
place in 30 seconds and at 140°F total
burning takes place in 5 seconds.
In view of the above, it is necessary to install a
thermostatic mixing valve which can

· reduce the temperature at the point of use
to a value lower than that of storage;

· maintain this value when the incoming
pressure and temperature conditions
vary.

Thermal disinfection

The diagram below shows the behavior of
the bacteria “Legionella Pneumophila” when
the temperature conditions of the water
in which it is contained vary, in laboratory
sample population.
In order to ensure proper thermal
“disinfection”, the value must not be below
140°F.

:

A thermostatic mixing valve mixes hot and cold water in such a way as to maintain a constant
set temperature of the mixed water at the outlet.
A thermostatic element is fully immersed into the mixed water. It then contracts or expands
causing movement of the piston, closing either the hot or cold inlets, regulating the flow rates
entering the valve. If there are variations of temperature or pressure at the inlets, the internal
element automatically reacts attempting to restore the original temperature setting.

Thermal shutoff

In the event of a failure of either the hot or cold supply, the piston will shut off, stopping water
discharging from the mixed water outlet.
The Caleffi valve requires a minimum temperature differential from hot inlet to mixed water outlet
of 20°F (11°C) to ensure the correct operation of the thermal shutoff feature.

Construction details

Double seat

The mixing valve has a special actuator which acts on a double water passage seat. This
produces a high flow rate with a reduced resistance, at the same time maintaining accurate
temperature control.

Anti-wear surfaces

The materials of construction in the 5231 series thermostatic mixing valve eliminates the
problem of jamming caused by mineral deposits. All the working parts, such as the PPSG40
shutter and EPDM seals, are made of a special anti-scale material, with a low friction coefficient,
providing long term high performance.

Low inertia thermostat

The temperature-sensitive element, the “motor” of the thermostatic mixing valve, is characterized
by a low heat inertia; this means that it reacts rapidly to variations in the incoming temperature
and pressure conditions, reducing the valve response times.

Temperature setting and locking

The control knob permits temperature setting, between min. and max., in one turn (360°). It
also has a tamper-proof system to lock the temperature at the set value.

160
140
120
100

80
60

32

Reference documents

For the prevention and control of Legionella,
see the National Regulations and applicable
Code of Practice.

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

COLD

HOT

MIXED