Question: What is the purpose of the blind cover plug on the pump inlet filter? Urgent~~~
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I’ve been using the equipment for some time now, and today I noticed that the plugs on the inlet filters of both hot oil pumps are leaking. They hadn’t leaked at all during the 5 years they’ve been in use. I’m just wondering what purpose these plugs serve; after all, there’s a drain system for draining oil, so it’s strange. It’s really annoying
If the filter element becomes dirty, it can be removed for cleaning. After cleaning, air is vented from this plug when oil is injected into the filter to prevent cavitation when the pump starts.
I disagree with the opinion above; the filter cover is installed facing downward. That’s for installing drain pipes; the filter equipment is a type of forming equipment, and some designs include such drain pipes, though they are blocked with plugs at the time of manufacturing – many pieces of equipment are like this.
Oh, it seems I didn’t explain it clearly enough. It’s not a “Y”-type filter; rather, it’s a 90-degree “L”-shaped pipe at the pump inlet, equipped with a blind cover. The filter itself is a cylindrical element that is placed horizontally but at a 90-degree angle to the direction of the pump shaft. There’s a plug with external threads on the blind cover. I noticed that many of the pumps in our installation have this kind of plug, but both of the hot oil pumps are leaking today, and we need to deal with each one separately. What’s the purpose of this anyway? Isn’t the pump’s exhaust discharged through the outlet drain?
Reply to 4# xaut: It would be best to have a photo, as that makes it much clearer!
I think it’s for sewage discharge and backwashing. When it’s time to flush the filter (of course, when it’s not too clogged), close the inlet valve, open this plug, then reopen the inlet valve to flush out the dirt from the filter, thus avoiding the need to remove the cover. It's just my personal opinion for reference only; as long as the building has photos, it will be easy to explain.
Agreement: it is the drain guide used during venting
Leakage from the filter blind cover plug can be caused by two possibilities: 1. The equipment has been in use for a long time, resulting in rust on the plug; 2. BSP threads are used for the plug’s connection, whereas NPT threads would be much better. The holes on the blind cover are sealed with plugs, and this is a standard practice followed by filter manufacturers when the equipment leaves the factory – unless you have special requirements! The position on the filter’s upper cover where a plug is installed is not actually meant for installing such a plug; it serves several purposes: 1. To install a pressure gauge – pressure gauges are cheaper than differential pressure meters, and they allow for simple monitoring of the pressure difference across the filter, which is useful for cleaning the filter. 2. To install a pressure relief valve – this prevents excessive pressure from building up, as the valve opens automatically when that pressure reaches a certain level. 3. To install an exhaust valve – when liquid enters the filter, the exhaust valve is opened; once liquid starts flowing out of the exhaust port, the valve can be closed, ensuring that no air remains in the filter. Whether this is necessary depends on the process requirements and the operation of the equipment
It is best to remove the plug on the blind cover and install a three-way valve; a pressure gauge should be attached to one port (to monitor the pressure difference and allow for timely cleaning of the filter), while the other port is used for venting and drainage