The oil drain kit is designed for use with an RV3, RV5, RV8 or RV12 pump (fitted with an EMF oil mist filter) which operates continuously with gas ballast switched on. You cannot use the oil drain kit if you want to introduce a purge gas into the RV pump. If you want to introduce a purge gas into the RV pump, you must fit a gas ballast adaptor to the pump and oil cannot be returned from the pump. When fitted, the oil drain kit continuously returns oil trapped in the oil mist filter to the pump. This reduces oil loss from the pump and minimises the need to check the pump oil-level and to refill the pump with oil. At high inlet pressures (above 200 mbar, 2 x 104 Pa), the oil drain kit will not work correctly. The Oil Drain Kit is not suitable for use with an RV pump which is used in hazardous processes.