Danfoss KVL 12, KVL 15, KVL, KVL 22, KVL 28 Data sheet
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Data Sheet
Crankcase pressure regulator
Type KVL
Ensures safe compressor operation
Crankcase pressure regulator type KVL is €tted in the suction line ahead of the compressor.
KVL protects the compressor motor against overload during start-up after long standstill periods or after defrost periods (high pressure in evaporator).
Features
• Accurate, adjustable pressure regulation
• Wide capacity and operating ranges
• Pulsation damping design
• Stainless steel bellows
• Compact angle design for easy installation in any position
• “Hermetic” brazed construction
• Available in a wide size range of „are and ODF solder types
• KVL 12 – KVL 22: may be used in the following EX range: Category 3 (Zone 2)
AI246886497547en-001001
Crankcase pressure regulator, Type KVL |
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Functions |
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Figure 1: Design/Function for KVL |
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1 |
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1 |
Protective cap |
2 |
= 8mm |
2 |
Gasket |
3 |
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3 |
Setting screw |
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4 |
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5 |
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4 |
Main spring |
6 |
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5 |
Valve body |
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6 |
Equalization bellows |
9 |
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7 |
Valve plate |
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8 |
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8 |
Valve seat |
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7 |
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9 |
Damping device |
The Crankcase pressure regulator type KVL opens at pressure fall on the outlet side, i.e. when the suction pressure ahead of the compressor drops below the set value.
The KVL only regulates based on the outlet pressure. Pressure variations on the inlet side of the regulator do not a†ect the degree of opening since the KVL is equipped with an equalization bellows (6). This bellows has an e†ective area corresponding to that of the valve seat.
The regulator is also equipped with an e†ective damping device (9) against pulsations, which normally occur in a refrigeration plant.
The damping device helps to ensure long life of the regulator without impairing regulation accuracy.
Figure 2: P-band and Offset
C |
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100% |
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S |
b |
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0.2 |
1 |
2 |
3 |
4 |
5 |
6 |
Min. |
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P |
O |
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Max. |
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A |
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C Capacity
b bar
S |
Set point |
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Oo†set
PP- band
A |
Adjustment range |
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Min. |
Min. setting point |
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Max. |
Max. setting point |
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Proportional band
The p-band is de€ned as the di†erence between the pressure at which the valve plate starts to open (set point) and the pressure at which the valve is completely open.
© Danfoss | Climate Solutions | 2021.02 |
AI246886497547en-001001 | 2 |
Crankcase pressure regulator, Type KVL
Example
If the valve is set to open at 4 bar and the valve p-band is 2 bar, the valve will give maximum capacity when the outlet pressure reaches 2 bar.
O€set
The o†set is de€ned as the di†erence between the pressure at which the valve plate starts to open (set point) and the pressure at which the valve reaches the necessary opening for the actual load.
The o€set is always a part of the p-band
Because optimal function of a refrigeration plant is best reached with fully open KVL, the term o†set is normally not used in connection with the KVL valve.
© Danfoss | Climate Solutions | 2021.02 |
AI246886497547en-001001 | 3 |
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