Installation guide / Operating instruction
Safety relief valves
SFA 10, SFA 10H, SFA 15
148R9527
148R9527
Fig. 1. Orientation
Fig. 2. Vibrations
Oil
Fig. 3. Piping precautions
© Danfoss | DCS (ms | 2020.11
Fig. 4. Piping precautions
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SFA 10(H) T / SFA 15 T
B
100 Nm
74 ft lb
DSV
b
a
SFA 10(H) T: G ½”
SFA 15 T: G ¾”
a
b
Alu-gasket (SFA 10(H) T / SFA 15 T)
Union nut (SFA 10(H) T G ¾”)
(SFA 15 T DN20)
Welding nipple (SFA 10(H) T DN15)
(SFA 15 T G 1”)
4
2 2
3
Alu-gasket
Union nut
DSV / Welding nipple
3
100 Nm
74 ft lb
100 Nm
74 ft lb
5
1
Welding connector (SFA 10(H) T DN15, 148F3075)
Welding nipple (SFA 15 T DN15)
Fig. 5. SFA 10(H) T / SFA 15 T (G-thread) installation
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NOTE: Add G4500 grease (148F3064)
to thread a and b on all SFA valves.
© Danfoss | DCS (ms | 2020.11
2
2
2
NPT ½”
DSV / Welding connector
Welding connector
2
NPT ¾”
1
148 F3076
Fig. 6. SFA 10(H) NPT installation
© Danfoss | DCS (ms | 2019.11
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Installation
Refrigerants
SFA 10 with CR O-ring is applicable to
R717, R744, HFC and HCFC.
SFA 10H is with EPDM O-ring and applicable for CO₂ with POE and PAG oil only.
Temperature range
For SFA 10 and SFA 15 with CR O-ring:
- Set pressure shall not be lower than
-30 °C (-22°F) saturation temperature.
- At static temperatures below -30 °C (-22 °F)
the CR O-ring becomes harder and full
tightness of the valve cannot be
guaranteed. Above -30 °C (-22 °F) the
CR O-ring will become soft and fully
functional again.
- Observe for R744 (CO₂)! Due to above the
min. set pressure for correct functional
valve in R744 (CO₂) is 27 bar (392 psig), to
ensure proper function of the valve in
case of a sudden relief.
Pressure range
The SFA valve is designed for a
max. working pressure of
SFA 10: 65 bar (944 psig).
SFA 15: 40 bar (580 psig).
The safety valve is adjusted to a specific
relief pressure stated on the ID plate.
After setting the valve is sealed with wire
and seal. To comply with EN13445-3, the
SFA10(H)/15 is limited for operation up to
500 full pressure cycles or equivalent set
pressure cycles.
Piping precautions
The valve is recommended for closed
circuits only.
Refrigerant purity
Danfoss cannot guarantee correct opening
and closing of the valve if the pressure
relieved refrigerant is polluted with dirt
and particles.
IMPORTANT:
THE INLET/OUTLET PIPE DIMENSIONS
MUST NOT BE SMALLER THAN THOSE
OF THE WELDING NIPPLES.
The valve is designed to withstand a high
internal pressure. However, the piping
system should be designed to avoid liquid
traps and reduce the risk of hydraulic
pressure caused by thermal expansion.
It must be ensured that the valve is
protected from pressure transients like
“liquid hammer” in the system.
During welding avoid welding debris and
dirt in the threads of the connections and
in the adjacent pipes.
Before assembly clean all parts exposed to
debris and dirt.
Valve orientation (see fig. 1)
The valve should be installed with the
spring housing pointing upwards.
Vibrations (see fig. 2)
The SFA valve should never be exposed to
thermic or dynamic stress from vibrations.
Outlet pipe orientation (see fig. 3)
To avoid dirt and condensate entering and
accumulating at the valve outlet avoid
piping lay out in upwards slope.
Oil trap (see fig. 4)
For SFA valves in applications with outlet
to the ambient an oil filled U-pipe is an
efficient protection against the entrance of
water and dirt.
Installation of SFA T with G-thread
(see fig. 5)
The SFA valve can be installed either in the
dedicated DSV change-over valve
(SFA 10(H) only) or directly in the system
piping via a threaded weld connector
148 F3075.
Follow these steps:
1. (Welding nipple/connector only).
Assemble the union nut and welding
nipple and place the assembly on the
system piping. Fully weld the welding
nipple to the system piping and
cool down
2. Add G4500 grease (148F3064) to
thread a. Place the alu gasket inside the
the union nut and install the SFA by
turning the union nut clockwise
3. Tighten to torque 100 Nm ( 74 ft lb)
4. Prepare and weld the outlet welding
nipple like described in step 1
5. Add G4500 grease (148F3064) to
thread b and tighten the outlet
connection to torque 100 Nm ( 74 ft lb)
Installation of SFA 10(H) NPT (see fig. 6)
The SFA 10(H) NPT valve can be installed
either in the dedicated DSV 10 NPT
change-over valve or directly in the system
piping via a threaded weld connector
(148F3076).
Follow these steps:
1. (Welding nipple/connector only). Place
the welding connector on the system
piping. Fully weld the connector to the
system piping and cool down
2. Add sufficient teflon tape or similar
sealing material on the SFA 10(H) inlet
and outlet
3. Insert the SFA 10(H) inlet to the
DSV/weld connector thread
4. Align and tighten by applying a
sufficient torque
5. Connect the SFA 10(H) outlet to the
discharge piping system, e.g. by use of
pipe union
Corrossion protection
The DSV valves are factory painted with a
red oxide primer. The external surface of
the SFA and DSV valve housing must be
prevented against corrosion with a
suitable protective coating after
installation and assembly.
© Danfoss | DCS (ms | 2020.11
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