Figure 30.MICRO-FOG LUBRICATOR

application as possible. Always select lubricators and locate them where different levels of lubrication are required, never attempt to fit one lubricator to supply a whole distribution system as differing parts willthen be over lubricated, whilst others areunder lubricated.Ensure that only special purposeMicro-Fog lubricators are used for bearing lubrication as other types are not suitable.Check that the lubricator chosen hassufficient flow capacity without excessive pressure drop for the pipe line size beingused (see figure 37 and individual lubricator performance graphs). associated with high flows and so be more energy efficient.For exceptionally high flow ratessmall amounts of lubricant (especially for anti-freeze usage) can be injected by smalllubricators into large distribution mains of 1to 2 " and above, where a full bore lubricatorwould be expensive in both cost and pressure drop.

Figure 31.LUBRICATOR FLOW RATES PipeUnitFlow (dm

/s)* Size

" pipe size and above, severalreservoir capacities are usually available. Where this is not possible because of space or usage rate utilise remote fill devices or liquid level switches to auxiliary systems.Where very high flows are encoun-tered use a fixed venturi type lubricator.Unlike standard types this does not automati- cally adjust to give a constant air/oil density, so the flow requirement needs to be essen- tially constant. This type of device will then not produce excessive pressure drops

*Flow at 6,3 bar and 0,5 bar pressure drop.

Although a high level signal may atfirst seem strange remember that overfilling will not only prevent the lubricator from performing its function of producing an air/oil mix of fog, but will distribute bulk lubricant into the pneumatic system, floodingit. Since lubricators require a minimumpressure drop to operate which is normally related to a flow, ensure that this minimum flow condition is met or there will be no oil output. It is important to note that leaks from compressed air systems are a source ofenergy loss and also such leaks are effec- tively a constant flow through the system. If alubricator with a very low start point is used then even a small leakage, if in excess of the start point will cause it to drip and supply oil to the system. This is often the cause of oil flooding during periods of shut-down, especially over weekends.Where continual usage exists selecta lubricator with sufficient reservoir capacity.For units in 1/2

Clean Compressed Air Brochure - 14694 LUBRICATOR SELECTION

Determine which parts of the system requirelubrication (some distribution lines will be to oil free areas such as paint spraying or breathing air applications).Determine what type of lubrication isrequired for each part of the system. Slowmoving heavy cylinders need high deliveryso chose an Oil-Fog type lubricator. Long runs of pipe in multi-valve circuits require a Micro-Fog (or several Oil-Fog) lubricators to lubricate effectively. High speed tools are better served by a Micro-Fog, as are tips of cutting tools.All lubricators are a source ofpressure drop and therefore energy loss, soalthough Micro-Fogs may be positionedalmost anywhere in a system select and place them as conveniently close to the

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