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

= 8mm

1 2

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Protective cap

Gasket

Setting screw

Main spring

Valve body

Equalization bellows

Valve plate

Valve seat

Damping device

100%

0.2 1 2 3 4 5 6

Min.

Max.

CbSOPAMin.

Max.

Capacity

bar

Set point

oset

P- band

Adjustment range

Min. setting point

Max. setting point

Crankcase pressure regulator, Type KVL

Functions

Figure 1: Design/Function for KVL

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 Oset

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.

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.

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