ISO 19349:2019 pdf free

ISO 19349:2019 pdf free.Plain bearings with liquid lubrication一Lubricant supply arrangements and monitoring
When the return flow is driven by gravity, oil return lines shall have a slope of at least 5 %. According to ISO 10438-1, oil drains shall be sized to run no more than half full when flowing at normal drain operating temperature at maximum flow conditions and shall be arranged to ensure good drainage (recognizing the possibility of foaming conditions). Junctions and changes in the direction of pipes shall be designed so as not to impair lubricant flow. Sharp bends and down or up loops shall be avoided.
Junctions in return pipes shall be located in the direction of flow. In order to prevent foaming, vertical slopes exceeding 1 m in length shall be avoided. No devices significantly impeding the flow in the return line, such as filters, etc. shall be installed.
Where more than one device (bearings, and possibly other consumers) is to be supplied with lubrication oil, the design of the oil supply and circulation system should mitigate against the potential harmful interactions in the return lines and oil reservoir caused by differential air pressure conditions.The basic design requirements for oil reservoirs are given by ISO 4413 in conjunction with ISO 10438-1.
Based on experience and with respect to air release and oil aging, the capacity of oil reservoirs should be approximately eight times the quantity delivered per minute. The factor eight may be reduced to three depending on the ratio of exposed surface area to volume in the oil reservoir, lubricant properties (air release additives), operating conditions, duty cycle and oil change interval. Small oil reservoirs in particular should have an internal weir or baffle plate between return and suction pipe to settle the returning oil and to permit entrained air in the oil to escape.
Oil reservoirs shall be suitably vented to allow entrained air to escape. In the – recommended – case of return pipes discharging below the reservoir oil level, vent holes shall be provided above the oil level so that the air in the reservoir is able to communicate with the air in the bearing housing via the partly filled return pipe. Oil reservoirs shall be equipped with an oil level indicator.ISO 19349 pdf free download.