In need of a education

[Coaldust]

Tyler D4C,

Why not just use a HE filter all the time?
Damn good question. You are a quick study.

My students would ask that question about half way through my contamination control class.

Quick answer is the design of mobile hydraulic systems, especially on compact equipment is always a compromise for space. Reservoirs and filters are made smaller than standard best practices to make them fit on the machine. Of course, cost is an issue, too.

The HE (clean-out) filters plug up very fast in normal ops. 50-100 hours, instead of the normal 500 hour change interval.

The manufacturer could install a super efficient filtration system, but the filter assemblies would be huge and costly. Compact equipment is built to a price point in that highly competitive market.

Plus, there is some planned obsolescence built in to keep the parts and service departments busy.

 

[Nige]

Problem with using HE filters as standard elements is that unless you feed the machine with clean oil on PMs the filters may plug up quicker than normal. That is something you have to live with until the system cleans up, and is the reason why some folks prefer standard elements - to avoid the hassle of having to change them outside PMs on the odd occasion.

i assume that your machine has a plugged hydraulic filter indicator light..?

 

[Nige]

The HE (clean-out) filters plug up very fast in normal ops. 50-100 hours, instead of the normal 500 hour change interval.

I'm not sure I'd agree 100% with that, with the caveat that "Not if the oil's clean in the first place they don't".

The location I've been working recently has a filtration plant for all their oil grades apart from engine oil. Hydraulic oil comes out of the guns in the shop at ISO 14/9 or better. They use HE filters as the standard element and under those conditions the filters will quite happily go 500 hours between changes under normal circumstances.

I would say on this machine and bearing in mind the hours it works Tyler is most likely going to be doing 6-monthly or annual filter changes rather than hours-based. Under those circumstances I'm confident HE filters will work for him.

 

[Tyler d4c]

Problem with using HE filters as standard elements is that unless you feed the machine with clean oil on PMs the filters may plug up quicker than normal. That is something you have to live with until the system cleans up, and is the reason why some folks prefer standard elements - to avoid the hassle of having to change them outside PMs on the odd occasion.

i assume that your machine has a plugged hydraulic filter indicator light..?

I believe it does

 

[Nige]

I believe it does

You'll need to keep an eye on it, especially in the early days.

I just sent you an email BTW.

 

[Tyler d4c]

You'll need to keep an eye on it, especially in the early days.

I just sent you an email BTW.

I got it im sure the alarm in the cab will be singing also. I'll be reading up on that email this evening im just about to leave to a power plant to do some work on a belt line. This day job always in the way of fun.

 

[John C.]

The issue in my eyes with the HE filters is that a dirty system will plug up the filters and allow the bypass to open letting the return oil go around the filters. The bypass valves are just springs on a poppet that open when differential pressure between the inlet and outlet get to a certain point. The springs have no adjustment and the differential changes as the system heats up. Many machines have a pressure switch installed across the filter but it only tells you when the pressure difference is high. It doesn't really tell you if the bypass valve has opened. If your system is clean, the standard filters are just fine. If you have had a failure, then the HE filters will help get the small stuff out of the system. If you have a problem with silica in the system, you have the issue of how it got in there and an HE filter will do you no good until you find that source and correct it.
Not to be nitpicker but I believe the molecule described in oil sample reports is silica and not silicon. Silica is basically dirt with quartz. Silicon is a similar molecule with different properties. Check out the link for a better explanation.
https://www.differencebetween.com/difference-between-silicon-and-vs-silica/

 

[Nige]

Hence my question did Tyler have a plugged indicator for the hydraulic filter on that particular machine. There is a likelihood that the first HE filter might plug within a short time.

Another valid point here would be to question if hydraulic oil was being added/topped up on a regular basis on the machine. Because if oil is leaking out then dirt & contamination is pretty much certain to be getting in. Then it's a case of fix the leaks first before trying to clean up the system. I suspect the answer will be "No" because @ 9ppm the silicon number is way too low to have any major sources of entry of dirt into the system. It would need Si to be greater than say 20 or 30 to indicate significant dirt entry.

I was always under the impression that, because the chemical symbol "Si" is used on the analysis reports, that it was referring to Silicon the element rather than Silica the mineral. However I have no proof of that - need to investigate further. It might be worth mentioning that because Silica is chemically Si02 (silicon dioxide) then silica should still show up in an analysis report under the "Silicon" heading because it is silicon-based.

 

[Nige]

Not to be nitpicker but I believe the molecule described in oil sample reports is silica and not silicon. Silica is basically dirt with quartz. Silicon is a similar molecule with different properties. Check out the link for a better explanation.
https://www.differencebetween.com/difference-between-silicon-and-vs-silica/

According to Page 3 of the attached it is silicon, or appears to be so to me.

 

[Nige]

The bypass valves are just springs on a poppet that open when differential pressure between the inlet and outlet get to a certain point. The springs have no adjustment and the differential changes as the system heats up. Many machines have a pressure switch installed across the filter but it only tells you when the pressure difference is high. It doesn't really tell you if the bypass valve has opened.

I may be wrong here but most of the systems I've come across the switch was a mecahnical one operated by the poppet when the filter went into bypass. On the smarter machines with VIMS the plugged filter alarm would not go off until the oil temperature went above a certain value even if the element went into bypass.

 

[Tyler d4c]

Like I think I mentioned before the only leaks I know of are the quick couplings maybe be a silly idea but why couldn't a fella put a second base on after the HE filter with the standard element for if and when the bypass opens

 

[Nige]

Keep an eye on the plugged filter indicator would be the easiest IMHO.

 

[Tyler d4c]

This is true just a idea may be good for some application. Over kill for this tho

 

[Lesch]

Like I think I mentioned before the only leaks I know of are the quick couplings maybe be a silly idea but why couldn't a fella put a second base on after the HE filter with the standard element for if and when the bypass opens

I was thinking of using a standard filter first and then the HE filter. That way the big stuff will e caught in the standard filter and not plug up the HE as quickly.....But what do I know

 

[John C.]

I don't think I've seen a pop up type indicator on any of the smaller machines I generally worked with. All the excavators, loaders and dozers I've put my hands on have the light on the dash but no connections to the poppet valve on the top of the filter whatsoever. The bypass is that plastic thing you remove from the top of the filter before you pull the filter out of the can. I have no doubt that the mining industry in the two hundred ton machine and higher has the profit margin to install quality. It isn't the same in the construction and logging industry. Those bypass lights come on every morning when the temps drop below 40 degrees F.

Even the filter carts I've worked with have the two colored ball to indicate restriction in the filter. A high efficiency filter in those will plug up pretty quick on a dirty system. I also have a couple of clients now that are permanently installing kidney loop systems on all their hydraulic systems. Some companies are big into oil sampling and dumping the machine when an accountant says to do so. The sampling in my mind is just a waste at that point. Others are just keep on keeping on and deal with issues when they come up. In my experience, once you know you have clean systems, do the factory recommended maintenance and you will be just fine.

I agree that silicon might be what the spectrogram sees on an elemental level but the oil labs all told me over the years that silica is the damaging substance. It is the indicator of dirt entering the system. I have run into people calling it silicone as well.

 

[Coaldust]

This is great discussion. Good stuff, Gents. Thoughtful posts.

I don’t believe there is a filter indicator on this machine.

 

[Tyler d4c]

This is great discussion. Good stuff, Gents. Thoughtful posts.

I don’t believe there is a filter indicator on this machine.

The base has a sensor of some kind in it must just turn the light on when the pressure is high

 

[emmett518]

Would it be safe to say I'm in the clear on the metal readings also?

What do they charge for an analysis?

 

[Tyler d4c]

What do they charge for an analysis?

15 or 20 bucks at the local dealer