CALEFFI 3048 Series User manual

www.caleffi.com
1
3048 Series
Dual Check Backflow Preventer
© Copyright 2023 Caleffi
Function
Low lead dual check valve backflow preventer for residential
domestic water supply lines or commercial low-hazard backflow
applications. It prevents reverse flow of unsafe water into main
system water supply. This can occur due to pressure changes in
the distribution network that can force water flow in reverse, or
backwards. The two inline serviceable check valves prevent any
contact between the two systems, closing automatically when
backflow conditions occur. The Caleffi 3048 series is certified to
ASSE 1024 by ICC-ES.
The valve complies with NSF/ANSI/CAN 61 (180°F/82°C Commercial
Hot) as certified by ICC-ES, and complies with NSF/ANSI/CAN 372,
low lead, and codes IPC and UPC or use in accordance with the US
and Canadian plumbing codes, as certified by ICC-ES.
Product range
3048 Series NPT male, NPT female, press, sweat, PEX crimp, PEX expansion pipe sizes 1/2”, 3/4”, 1”
NA10884
Technical specifications
Materials
Body, retaining ring and lock nut: DZR low-lead brass CW724R-M
Check valve: EPDM, PPO
Spring: stainless steel
O-rings: peroxide-cured EPDM
Performance
Max. working pressure: 160 psi (11 bar)
Operating temperature range: 32 to 180°F (0 to 82°C)
Medium: water
Flow rate: see graph
The backflow preventer is ICC-ES certified to ASSE 1024, and complies with NSF/ANSI/CAN 372, low lead laws,
and NSF/ANSI/CAN 61 as certified by ICC-ES. It meets codes IPC, IRC and UPC for use in accordance with the
US and Canadian plumbing codes.

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CAUTION: All work must be performed by qualified personnel trained in the
proper application, installation, and maintenance of systems in accordance
with all applicable codes ordinances.
CAUTION: Over-tightening and breakage can occur with the use of Teflon®
pipe joint compounds. Teflon® provides lubricity so that care must be
exercised not to over-tighten joints. Failure to follow these instructions could
result in property damage and / or personal injury.
CAUTION: System fluids under pressure or temperature can be hazardous.
Be sure the pressure has been reduced to zero and the system temperature
is below 100°F (38°C). Failure to follow these instructions could result in
property damage and/or personal injury.
CAUTION: If the device is not installed properly, according to the instructions
contained in this manual, it may not operate correctly and may endanger the
user.
Caleffi shall not be liable for damages resulting from stress corrosion, misapplication or
misuse of its products.
CAUTION: Clean the pipes of any debris, rust, incrustations, welding slag
and any other contaminants. For optimal operation, air in the system must
be removed.
CAUTION: Make sure that all the connecting pipework is water tight.
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.P65Warning.ca.gov.
This safety alert symbol will be used in this manual to draw attention to safety related
instructions. When used, the safety alert symbol means ATTENTION! BECOME ALERT!
YOUR SAFETY IS INVOLVED! FAILURE TO FOLLOW THESE INSTRUCTIONS
MAY RESULT IN A SAFETY HAZARD.
SAFETY INSTRUCTION

3
Ce symbole d’avertissement servira dans ce manuel à attirer l’attention sur la sécurité
concernant instructions. Lorsqu’il est utilisé, ce symbole signifie. ATTENTION! DEVENEZ
ALERTE ! VOTRE SÉCURITÉ EST EN JEU ! NE PAS SUIVRE CES INSTRUCTIONS PEUT
PROVOQUER UN RISQUE DE SECURITE.
Caleffi ne pourra etre tenue responsable des dommages resultant de la corrosion, d’une
mauvaise utilisation ou une mauvaise utilisation des produits.
AVERTISSEMENT: Ce produit peut vous exposer à des produits chimiques
comme le plomb, qui est connu dans l’État de Californie pour causer le
cancer, dommages à la naissance ou autre. Pour plus d’informations rendez-
vous www.P65Warnings.ca.gov.
AVERTISSEMENT: Tous les travaux doivent être effectués par du personnel
qualifié formé à la bonne application, installation et maintenance des
systèmes conformément aux codes et règlements locaux.
AVERTISSEMENT: Un serrage excessif et une rupture peuvent survenir
avec l’utilisation de Teflon® composés de joint de tuyau. Le Teflon® offre
un pouvoir lubrifiant de sorte que les soins doivent être exercé pour ne pas
trop serrer les joints. Non-respect de ces instructions pourrait entraîner des
dommages matériels et / ou des blessures corporelles.
AVERTISSEMENT: Les liquides du système sont sous pression ou de la
température peivent être dangereux. Être sûr que la pression a été réduite
à zéro et la température du système est inférieure à 100°F (38°C). Le non-
respect de ces instructions peut entrainer des dommages matériels et/ou des
blessures.
AVERTISSEMENT: Nettoyer les tuyaux de tout debris, roille, incrustations,
scories de soudure et d’autres contaminants.Pour un fonctionnement optimal,
de l’air dans le system doit etre retire.
AVERTISSEMENT: S’assurer que tous les raccordements sont étanches.
CONSIGNE DE SÉCURITÉ
AVERTISSEMENT: Si le valve, n’est pas installe, mis en service et Entretenu
correctement, selon les instructions contenues dans ce manuel, il Peut ne pas
fonctionner correctement et peut mettre en danger l’utilisateur.

4
DIRECTION
OF FLOW
WATER METER DUAL CHECK
The Caleffi 3048 series dual check backflow preventer is typically installed downstream of a water
meter. A pressure reducing valve (if required) may be installed on either side of the dual check
backflow preventer, all subject to local codes and standards.
The dual check backflow preventer can be installed in either a horizontal or vertical pipe; the
checks are spring loaded and will function independent of orientation. Verify that the flow direction
matches the flow indication arrow on the dual check backflow preventer.
If installing models with sweat tailpiece connectors, always sweat the connectors in place then
install the 3048 union body. Attempting to sweat the fittings with the body in place may damage
the check valves.
For serviceability, always install the 3048 in an accessible location and protect the 3048
from potential freezing conditions. Installing isolation valves is highly recommended to permit
disassembly for servicing.
When installing the dual check backflow preventer, make sure not to over-tighten the connections.
Over time, a material stress failure can occur with subsequent water leakage causing damage.
The 3048 has dual union connections with Posi-Stop o-ring seals which do not require pipe dope
or tape. See graphic on next page.
Typical dual check backflow preventer pit installation:
Installation:

5
Spring check valves
Posi-Stop™ O-ring seals
3048 series dual check backflow preventer section view:
Service, maintenance:
The Caleffi 3048 should be inspected and cleaned, rebuilt or replaced every 5 years. If excessive
pressure drop is experienced in the domestic water supply, dirt or other debris may be causing higher
than normal pressure drop in the dual check backflow preventer. The 3048 can be easily inspected
by removing the body from the dual union connectors. To disassemble the check valves, remove the
sealing brass ring from the downstream side.

Dimensions:
6
B
A
NPT female
sweat
press*
NPT male
PEX crimp
PEX expansion
C
Code A B C Wt.
(lb/kg)
NPT female threaded connections
304843A 1⁄2" 213⁄16” 51⁄4” 1.2/0.5
304853A 3⁄4” 213⁄16” 5½” 1.6/0.7
NPT male threaded connections
304840A 1⁄2” 213⁄16” 55⁄16” 1.0/0.4
304850A 3⁄4” 213⁄16” 51⁄8” 1.2/0.5
304860A 1” 213⁄16” 513⁄16” 1.6/0.7
Sweat connections
304849A 1⁄2" 213⁄16” 49⁄16” 1.2/0.5
304859A 3⁄4” 213⁄16” 51⁄16” 1.6/0.7
304869A 1” 213⁄16” 513⁄16” 1.6/0.7
*Lay length for press:
size 1/2”: 3 1⁄2inch
size 3/4”: 3 3⁄8inch
size 1”: 3 7⁄8inch
Code A B C Wt.
(lb/kg)
Press connections*
304846A 1⁄2" 213⁄16” 53⁄16” 1.0/0.4
304856A 3⁄4” 213⁄16” 515⁄16” 1.2/0.5
304866A 1” 213⁄16” 57⁄8” 1.4/0.6
PEX crimp connections
304847A 1⁄2” 213⁄16” 67⁄16" 1.0/0.4
304857A 3⁄4” 213⁄16” 67⁄16” 1.2/0.5
304867A 1” 213⁄16” 65⁄8” 1.4/0.6
PEX expansion connections
304848A 1⁄2" 213⁄16” 77⁄16” 1.0/0.4
304858A 3⁄4” 213⁄16” 77⁄16” 1.2/0.5
304868A 1” 213⁄16” 77⁄16” 1.4/0.6

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Hydraulic characteristics
0
2
4
6
8
10
12
14
16
0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25 27.5 30 32.5 35 37.5
Flow rate, GPM
psi
0 9.5 28 47 66 85 104 123 142
GPM
LPM
1/2”
3/4”
1”
kPa
83
55
42
28
14
0
110
96
psi
3048 series 1/2 inch 3/4 inch 1 inch
Cv 8.0 9.5 10.5
Code A B C Wt.
(lb/kg)
Press connections*
304846A 1⁄2" 213⁄16” 53⁄16” 1.0/0.4
304856A 3⁄4” 213⁄16” 515⁄16” 1.2/0.5
304866A 1” 213⁄16” 57⁄8” 1.4/0.6
PEX crimp connections
304847A 1⁄2” 213⁄16” 67⁄16" 1.0/0.4
304857A 3⁄4” 213⁄16” 67⁄16” 1.2/0.5
304867A 1” 213⁄16” 65⁄8” 1.4/0.6
PEX expansion connections
304848A 1⁄2" 213⁄16” 77⁄16” 1.0/0.4
304858A 3⁄4” 213⁄16” 77⁄16” 1.2/0.5
304868A 1” 213⁄16” 77⁄16” 1.4/0.6
69
0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25 27.5 30 32.5 35 37.5
16
14
12
10
8
6
4
2
0
Safety
If the dual check backflow preventer valve is not installed, commissioned and maintained
properly in accordance with these instructions, it may not operate correctly, and may cause
damage to objects and/or people. Make sure all the connections are watertight.

Caleffi North America, Inc.
3883 West Milwaukee Road
Milwaukee, WI 53208
T: 414.238.2360 F: 414.238.2366
8
04-2023
NOTES
For Technical Support call 1-414-338-6338, or
email techsupport.us@calef.com