Klüber Summit RHT 68


Klüber Summit RHT 68 Is a paraffin-based mineral oil especially developed for ammonia refrigeration compressors.


Your benefits at a glance


– Low solubility in ammonia
– Excellent flow characteristics at low temperatures
– Lower maintenance costs due to long oil change intervals and reduced oil consumption
– Easier changeover due to neutral behaviour towards seals
– High refrigeration efficiency due to reduced oil deposits
– Lower operating costs due to long filter and oil separator lifetimes
– Lower oil carryover than with naphthene-based mineral oils


Your requirements – our solution


Klüber Summit RHT 68 and Klüber Summit RHT 100 are refrigeration compressor oils on the basis of highly purified, hydrogenated mineral oils.

Klüber Summit RHT 68 and Klüber Summit RHT 100 meet the requirements of DIN 51 5031, KAA.




Klüber Summit RHT 68 is used for the lubrication of screw-type and reciprocating piston compressors in industrial refrigeration plants.

Klüber Summit RHT 100 was especially developed for the operation of reciprocating piston compressors requiring a higher viscosity due to specific operating conditions such as higher operating temperatures in NH3 heat pumps.

As Klüber Summit RHT 68 and Klüber Summit RHT 100 are highly refined oils, oil carryover is considerably lower than with conventional mineral oils. This leads to lower oil consumption. The viscosity of Klüber Summit RHT 68 and Klüber Summit RHT 100 remains stable at a level since they contain only a small amount of highly volatile hydrocarbons. The oils’ high
evaporation stability prevents viscosity increases and thus premature oil change.
The hydrogenated base oil is chemically stable and was designed in particular to withstand the influence of ammonia.

While conventional mineral oils tend to blacken when reacting with ammonia, and deposits tend to form in the refrigeration
circuit, this is not the case with Klüber Summit RHT oils.

Oil change intervals can be extended significantly. Due to their low solubility in ammonia, Klüber Summit RHT oils contribute to
refrigeration plant efficiency. Experience has shown that Klüber Summit RHT 68 can be used with evaporator temperatures as
low as -39 °C, and Klüber Summit RHT 100 as low as -30 °C.

Klüber Summit RHT 68 and Klüber Summit RHT 100 are chemically miscible with mineral oils, alkylbenzenes and PAObased refrigerator oils. They may therefore be used to top up such oil fills. The full performance capacity of Klüber Summit
RHT 68 and Klüber Summit RHT 100 will only come to bear with a complete change of the oil and filters.

Klüber Summit RHT 68 is neutral towards most chloroprene and neoprene seals typically used in refrigeration equipment. Klüber Summit RHT oils are less soluble than naphthene-based mineral oils, which reduces the influence on the swelling behaviour of the seals to a minimum. In some rare cases, a changeover from naphthene-based refrigerator oils to a Klüber Summit RHT oil may lead to leakages as the oil change may cause seals to shrink to their original size. In our experience, such leakages are very small and reversible, depending on the runtime and the maintenance condition of the refrigerator.

Application notes


Drain old oil from the whole circuit of the refrigeration compressor while still warm. We recommend replacing all oil filters and oil separators and completely drain oil traps of the refrigeration circuit.

Then refill the compressor with Klüber Summit RHT 68 or Klüber Summit RHT 100.


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