Norgren Collateral

Solutions Q&A 17 Some lubricators are designed around a cartridge insert. In this case it may be possible to swap the cartridge and sight domes to change the function. 5.3 Setting lubricator drip rates ? 5.3.1 What is the correct drip rate setting? The drip rate will depend on the application, the amount of lubrication required, the flow through the lubricator and the lubricator type. In Micro-Fog lubricators only 10% of the droplets in the sight dome are carried downstream. The drip rate in Micro-Fog lubricators therefore tends to be much higher. The following table can be used to estimate drip rate for required flow. This is very much a rule of thumb. In practice it is necessary to fine tune the oil drip rate in each application. Typical drip rate per minute Micro-Fog Typical drip rate per minute Oil-Fog Approx flow scfm (dm3/s) 20 2 10 (5) 40 4 20 (10) 60 6 30 (15) 80 8 40 (20) 100 10 50 (25) 120 12 60 (30) ? 5.3.2 Can the drip rate be shut off? In lubricators with needle valve type sight dome, yes. Some IMI Norgren sight domes use a felt pad which is soaked in oil at the point where the drops are formed. With this type of sight dome the oil droplets cease once the felt pad dries out. With the new style dome (L72/73/74 and L07) complete shut off is not possible. Minimum adjustment for the drip rate is around 1 drop per minute. 5.4 Filling methods 5.4.1 Oil-Fog and Micro-Fog lubricators: The standard Oil-Fog lubricators can be filled under pressure ie without switching off the upstream air. When a fill plug is removed a check valve in the lubricator body isolates the inlet pressure from the bowl and the reservoir will depressurize. The lubricator can then be filled with oil. When the fill plug is replaced, the reservoir will re-pressurize. The standard Micro-Fog unit can only be filled without isolating the upstream pressure if a remote fill or quick fill nipple accessory is fitted. To remove the fill plug of a Micro-Fog lubricator while under pressure can be dangerous. If in doubt shut off the upstream air! 5.4.2 Remote Fill Devices: The remote oil fill system provides a means of filling from a remote fill point, a single lubricator or a bank of lubricators manifolded together. The remote fill point may be connected to a portable reservoir or to a centralized, permanent reservoir. A portable reservoir permits the use of different lubricants in different groups of lubricators to suit the requirements of the machinery being lubricated. The lubrication oil must be fed in at a higher pressure than exists in the bowl. The devices are NOT intended for connection to an oil feed line which is under constant pressure from a pump or pressurized reservoir. The device cannot reset until the pressure is removed. Such lines are a potential safety hazard if they should leak or become broken. 5.4.3 Quick Fill Nipples: The quick fill system is an alternative which allows ease of filling a single Micro-Fog or Oil-Fog lubricator without switching off the mains air (on some units the quick fill nipple replaces the filler plug). To fill the lubricator, a quick fill connector piped to a portable oil reservoir is snapped in place over the quick fill nipple. The main oil reservoir can now be pumped (or pressurized) to a pressure greater than the lubricator bowl and the lubricator filled. 5.5 Options and accessories ? 5.5.1 Where can liquid level switches be fitted? Liquid level detection methods can be attached to the 1 quart bowl and 2 & 5 gallon tanks. ? 5.5.2 Where can remote fill and liquid level switches be fitted? The smaller bowls, L73 and up, are all capable of either remote fill or liquid level detection (but not both at the same time!). The 2 quart and 2 & 5 gallon tanks only can have the liquid level switches fitted. 5.5.3 How do liquid level switches work? Liquid level switches are bipolar reed switches which change state when the float rises and falls. Liquid level switches are normally connected to give an electrical signal when the float falls (ie when the liquid level is too low). In critical applications the logic could be reversed. Maximum and minimum settings are possible too. 5.6 Large tanks/reservoirs ? 5.6.1 Which units have large tanks/reservoirs? All units in basic 1/2" and above have optional larger bowls/tanks. Olympian Plus and Excelon 74 are limited to 1 quart as standard. For 2 and 5 gallon capacity use 68/17 Series, or the 10-028/-076 (2") lubricators. 5.7 Application specific units ? 5.7.1 What is a fixed venturi (bi-directional) lubricator? Standard IMI Norgren lubricators use a flow sensor to achieve constant oil density with varying flows. In some applications high flow is more important than constant density and a fixed venturi can be used instead of a flow sensor. It may also be useful in systems with rapid cycling. Consult IMI Norgren for more details.

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