Function

The Caleffi DELTA 2™ high-low thermostatic mixing valve delivers tempered water for a wide range of flows in a single assembly, applicable for institutional and commercial applications such as hotels, nursing homes, hospitals and schools. The NA52367HL is furnished assembled and pressure tested with high range and low range thermostatic mixing valves, Caleffi code 521509A and 523178A; along with a pressure reducing valve, Caleffi code 535970HA, to function as one system in providing a broad flow range from 1* gpm to 50 gpm. This one-piece assembly also contains an outlet thermometer, cold water inlet check valves, and shut-off ball valves.

Thermostatic mixing valves meet requirements of ANSI/NSF 372-2011 and certified to ASSE 1017, CSA B125.3, UPC, IPC, Low Lead Laws and listed by ICC-ES for use in accordance with the U.S. and Canadian plumbing codes. Pressure reducing valve is certified to ASSE 1003, CSA B356, NSF 61, NSF 372 Low Lead Laws and listed by ICC-ES.

Delta2™ high-low mixing valve

NA52367HL © Copyright 2018 Caleffi

NA10477.01

www.caleffi.com

Product rangeNA52367HL: Adjustable thermostatic high-low mixing valve..............................................................................................................................................1 inch copper inlet x 1¼ inch copper outlet

Technical specification

PerformanceSuitable fluids: waterMax. working pressure: 200 psi (14 bar) Max. inlet temperature: 180°F (80°C)Mixed temperature setting range:

95 to 150°F (35 to 66°C)Flow range: 1* to 50 gpm (3.8 to 190 l/min)Connections:

- inlets: 1” copper; -outlet: 1¼” copper

Reference documentation: 521: Instruction Sheet 38476 5231: Instruction Sheet 48277535: Instruction Sheet NA10397

Min Flow*

Pressure Drop (Inlet - Outlet)

5 10 15 20 25 30 PSI

0.3 0.7 0.97 1.4 1.7 2.1 BAR

1.0 16 28 36 42 47 50 gpm

3.7 60 105 135 160 180 190 l/min

*Minimum flow rate is 0 gpm when recirculation flow rate is 1 gpm or greater.

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Leave this manual for the user.

CAUTION: If the thermostatic mixing valve is not installed, commissioned and maintained properly, according to the instructions contained in this manual, it may not operate correctly and may endanger the user.

CAUTION: Make sure that all the connecting pipework is water tight.

CAUTION: When making the water connections, make sure that the pipework connecting the Delta2™ thermostatic mixing valve is not mechanically overstressed. Over time this could cause breakages, with consequent water losses which, in turn, could cause harm to property and/or people.

CAUTION: Water temperatures higher than 100ºF (38ºC) can be dangerous. During the installation, commissioning and maintenance of the Delta2™ thermostatic mixing valve, take the necessary precautions to ensure that such temperatures do not endanger people.

CAUTION: In the case of highly aggresive water, arrangements must be made to treat the water before it enters the thermostatic mixing valve, in accordance with current legislation. Otherwise the thermostatic mixing valve may be damaged and will not operate correctly.

SAFETY INSTRUCTION

CAUTION: All work must be preformed by qualified personnel trained in the proper application, installation, and maintenance of systems in accordance with all applicable codes and ordinances.

This safety alert symbol will be used in this manual to draw attention to safety related instructions. When used, the safety symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED! FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN A SAFETY HAZARD.

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WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Operating principle

The mixing valves are piped in parallel to the hot and cold inlet lines and the pressure reducing valve is piped on the outlet (mixed temperature) side of the larger thermostatic mixing valve. When demand is low, the small thermostatic mixing valve provides the needed water flow. When demand increases, indicated by increasing differential pressure in the system, the pressure reducing valve sees this differential and opens to allow flow through the larger thermostatic mixing valve.

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-10

0

1020

3040

5060

70 80

9010

0

020

30405060

70

8090

100110

120

130

140150 160

180190

200

41”

18”

10”

MIXED

HOTCOLD

Dimensions

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Use

Caleffi Delta2™ code NA52367HL high-flow thermostatic mixing valve is designed to be installed at the hot water heater. The NA52367HL valve cannot be used for tempering water temperature at fixtures as a point-of-use valve. It is not designed to provide scald protection. For safety reasons, it is advisable to limit the maximum mixed water temperature to 120°F when anti-scald devices are not used at each fixture.

Construction details

-10

0

1020

3040

5060

70 80

9010

0

020

30405060

70

8090

100110

120

130

140150 160

180190

200

MIXED

COLD HOT

535

H S

erie

s

3045

60

HO

T

COL

D

MIX

MINMAX7 1 2

H C

Pressure reducing valve:code 535970HA, 1 ¼”

Thermostatic mixing valve:code 5231178A, 1 ¼”

Thermostatic mixing valve: code 521509A, ¾”.

Check valves on mixing valve cold inlets

Recirculation pump sizing curve

*∆P (Inlet - Outlet)

*∆P

(psi

)

4

-100

10

20

30405060

70

80

90100

020

3040

5060

70

8090100

110

120

130

140150

160180

190

200

MIXED

COLD

HOT

535H Series

304560

HOT

COLD

MIX

MIN

MA X

71

2

HC

Installation

Before installing a Caleffi Delta2™ high-flow 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 Delta2™ 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.

The Caleffi Delta2™ thermostatic mixing valve must be installed by qualified personnel in accordance with the diagrams in this brochure, taking into account all current applicable standards.

The following are shown on the thermostatic mixing valve bodies:- Hot water inlet, color red and marked “HOT”. - Cold water inlet, color blue and marked “COLD”. - Mixed water outlet, marked “MIX”.

The Caleffi Delta2™ thermostatic mixing valve can be installed in any position, either vertical or horizontal. However, the pressure reducing valve must not be installed upside down. In this case, the PRV can be rotated within the unions (A).

5

-10

0

1020

3040

5060

70 80

9010

0

020

30405060

70

8090

100110

120

130

140150 160

180190

200

MIXED

COLD HOT

535

H S

erie

s

3045

60

HO

T

COL

D

MIX

MINMAX7 1 2

H C

-100

10

20

30 40 5060

70

80

90100

020

3040

5060

70

8090 100

110

120

130

140

150

160

180

190

200

MIXED

COLD

HOT

535 H Ser ies

304560

HOT

COL D

MIX

MIN

MAX

71

2

HC

-100

10

20

30405060

70

80

90100

020

3040

5060

70

8090100

110

120

130

140150

160180

190

200

MIXED

COLD

HOT

535H Series

304560

HOT

COLD

MIX

MIN

MA X

71

2

HC

A

Commissioning

The Caleffi Delta2™ thermostatic mixing valve must be commissioned in accordance with current standards by qualified personnel using temperature measuring equipment. The integral outlet port temperature gauge provides a time-saving temperature setting process to get to the desired temperature.

After installation, the valve system must be tested and commissioned in accordance with instructions given below, taking into account current applicable standards.

1) Ensure that the system is clean and free from dirt or debris before commissioning the thermostatic mixer.

2) The valve must be commissioned by measuring the temperature of the mixed water emerging at the point of use. Refer to the setup instructions.

3) The maximum outlet temperature from the valve must be set accounting for fluctuations due to simultaneous use. It is essential for these conditions to be stabilized before commissioning.

4) Adjust the temperature using the adjusting knob on the thermostatic mixing valves. For safety reasons. it is advisable to limit the maximum mixed water temperature to 120ºF in domestic hot water systems.

5) The temperature may be adjusted using the control knobs.

a) Adjust the temperature of the mixed water to the desired value. b) Measure and record the temperature at the cold and hot water inlets. c) Measure and record the temperature of the water delivered from the tap at the lowest and highest flow rates.

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Check valves

In systems with thermostatic mixing valves, check valves should be installed to prevent undesired backflow. The Delta2™ thermostatic mixing valve is supplied complete with check valves on the cold water inlets to the two thermostatic mixing valves.

Locking the setting for thermostatic mixing valves

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.

MIN MAX7

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3

Index Point

Temperature setting and lockingThe control knobs on the integral thermostatic mixing valves permit 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. The temperature is set to the required value by means of the knob with the graduated scale, on the top of the valve. Refer to specific instructions for each of these valves

Application diagram

Pos. Min. 1 2 3 4 5 6 7 Max

T (ºF) 81 90 100 111 120 127 138 145 152

T (ºC) 27 32 38 44 49 53 58 63 67

with: T = 155ºF (68ºC) . T = 55ºF (13ºC) . P = 43 psi (3 bar) Hot Cold

521509A

Pos. Min. 1 2 3 4 5 6 7 Max

T (ºF) 95 104 109 117 122 129 136 142 150

T (ºC) 35 40 43 47 50 54 58 61 66

523178A

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Setup Instructions

Once the unit is piped in to the hot and cold water sources and connected to the fixtures, follow these instructions for proper operation.

Step One:

Set the small mixing valve to deliver 10°F less than desired mixed outlet temperature. Example: desired temperature of 120°F requires the small mixing valve be set to 110°F.

• Isolate the pressure reducing valve and large mixing valve so all flow will pass through the small mixing valve. Do this by simply closing the ball valve at the outlet of the pressure reducing valve indicated with circle X in diagram.

• Open the appropriate amount of fixtures to achieve approximately 2 gpm of flow.

• Adjust the small mixing valve set point knob until the outlet gauge reads 10°F less than the desired mixed outlet temperature.

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Step Two:

Set the large mixing valve to the desired mixed outlet temperature.

• Isolate the small mixing valve so all flow will pass through the large mixing valve and pressure reducing valve. Do this by simply closing the ball valve in the outlet line coming from the smal mixing valve indicated with circle X in diagram. Open the other ball valve.

• Open the appropriate amount of fixtures to achieve approximately 12-14 GPM of flow.

• Adjust the large mixing valve setpoint knob until the gauge reads the desired mixed outlet temperature.

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Step Three:

Set pressure reducing valve.

• Maintaining 12-14 GPM.

• Open both isolation valves to allow flow to pass through both mixing valves.

• Observe the final outlet temperature

• Adjust the pressure reducing valve until mixed outlet temperature is 6-7°F lower than desired mixed outlet temperature. This means the pressure reducing valve is beginning to open and allow flow through the large mixing valve.

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Step Four:

Set small mixing valve to desired mixed outlet temperature.

• Isolate the large mixing valve and pressure reducing valve.

• Open the appropriate amount of fixtures to achieve approximately 2 GPM of flow.

• Adjust small mixing valve setpoint knob until the gauge reads desired mixed outlet temperature.

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Caleffi North America, Inc.3883 West Milwaukee RoadMilwaukee, WI 53208T: 414.238.2360 F: 414.238.2366

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Troubleshooting

Under normal operating conditions the Caleffi Delta2™ code NA52367HL high-low thermostatic mixing valve will provide a very high level of performance. This system includes two thermostatic mixing valves and one pressure reducing valve which must be regularly maintained, individually, following those specific instruction sheets. However, in some circumstances, where the following maintenance schedule is not followed problems may arise.

Recommended maintenance schedule:Tests should be conducted regularly to monitor the Delta2™ thermostatic mixing valve performance, as deterioration of performance could indicate that the valve system and/or the entire operating system require maintenance. If, during these tests, the temperature of the mixed water has changed significantly in comparison with the previous test, the details given in the installation and commissioning sections should be checked and maintenance conducted.

The following should be checked regularly to ensure that the optimum performance levels of the valve are maintained. Check every 12 months at least, or more often if necessary.

1) Check and clean the system filters.

2) Check that any check valves positioned upstream of the Caleffi thermostatic mixing valve are operating correctly, without problems caused by impuritites.

3) Limescale can be removed from internal components of the thermostatic mixing valve by immersion in a suitable de-scaling fluid.

Symptoms Cause Corrective action

Hot water at the cold taps a) Operation of check valve is hindered; Check valve is not sealing correctly. b) Check valves not fitted.

- Replace faulty check valve

Fluctuating mixed water temperature

a) Erratic supply temperatures at the inlet of the valve. b) Starvation of the water supplies at the inlets of the valve. c) Incorrect commissioning of the valve.

- Restore inlet conditions within the limits of the valve.

Erratic flow of water from the valve

a) Insufficient water supplies b) Fluctuations in the supply pressures/temperatures. c) Adverse effect created by other draw off points on the system

- Stabilize inlet supply condi-tions.

No flow of water from the valve

a) In-line filters blocked. b) Insufficient supply pressures. c) Debris obstructing valve operation.

- Clean filters - Resore inlet supplies - Clean debris or scale from the valve.

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