Hourmeter that Runs off Hydraulic Flow?

Why not just hook the output of a flow meter up to an hour meter?

No flow, no time registers.

sure

hook up a big ( brick sized ) bulky expensive $ 3000 flow meter to an hour meter

much better option than finding an off the shelf hour meter for less than $ 100 , that would take up as much space as.....an hour meter ?

i want to fit them permanantly to hydraulic machines that dont have electrical power

accounts department might ask why we purchased 300 flow meters this month at $ 3000 each ?

there are hour meters out there with built in long life battery that activate off vibration .... but thats no good to us when our machines can sit parked up in a job site where there is rock breakers hammering all day causing our equipment to register run time....

;)

$100? Is that all the reading is worth?

Use of hydraulics means you have some type of pressure during flow. Pressure switch to turn hour meter on and off.

as stated the machines dont have electrical power

i want a small compact simple reliable device that i can tee in to existing hydraulic fittings.

Get a battery run hour meter. All the switch has to do is make or break battery connection.

yes

LCD hourmeters with built in ( 5 year ) battery could work , unfortunately the pressure switches i looked at so far had a maximum pressure of 3000 PSI and some of our machines can see peak pressure of 370 - 400 bar ( 5800 PSI ).

I could fit them to the return port of the system ( 20 - 30 bar ) ,but inexperienced operators can ( and do ) apply reverse hydraulic flow to the system which would blow their guts out.

i could fit a check valve to protect against this scenario but that adds more pressure drop ( inefficiency ) and cost to the circuit build price

Measuring on the exhaust side would get over the pressure problems.

So my question is; is there any pressure fluctuation, or pulsing, or frequency [eg, from a motor, or cycling piston, tool feedback] in the exhaust fluid?

If so, then an otherwise 'insulated' vibration triggered meter could be attached to a diaphragm 'T'd' into the flow.

A loop of hose may also shake enough - depending on ....

This would give you 'working time', rather than 'flow time' [assuming it is a bypass off load circuit]

pressure fluctuations and pulsing do exist in this application..... but not always

some of the better operators run these things like a swiss watch , while others treat them like stolen car

a sensor attached around a hose could pick up 90 % of the run time but there is no guarantee that there wont be periods going undetected

i think 100 % accurate consistency would be obtained with a pressure sensor teed in to the hose fittings.

some people use pop up sensors on oil filters to indicate that a filter needs replacement but our experience has been that a pressure spike makes them pop prematurely and we would prefer the hours runtime for reference.

Sensing the operators presence is an option.

But to actually help with this I think I need to know what the thing is, or does.

You can use the private mail option [by clicking on my ID] if you don't want the IP revealed on open forum. Same would apply to any member above you might think could help. Like RVZ717 who despite the Brady bunch avatar, does know stuff.

thanks but i am looking for something small and simple which is a finished unit

buy it

bolt it on

forget about it

i dont want to buy components parts and assemble them into a unit that has risk of broken wires or fault prone weak points

sealed

encapsulated

self contained

no additional parts needed

I have emailed the biggest manufacturers i could find around the globe , if none of them reply that they have one , i sure as hell bet they will stick it on the drawing board to produce one.

You should be able to find something here....

http://www.alibaba.com/products/Digital_Flow_meter/--15370401.html?tracelog=detail_sn_cat

nope . thats flow meters

i want hourmeters

i searched for hourmeters on that page too , but nope.

thanks anyway

Why don't you give RVZ717 a pm?

Do a search in CR4 for him. This is his area of expertise.

http://en.wikipedia.org/wiki/Hobbs_meter

See #2

Better yet.

do i want the cheapest way out ?

No

I want reliable , small , simple , compact , encapsulated against dust and water

If i have to assemble 2 or 3 component parts with wires and battery then there is 2 or 3 times failure factor that comes with it.

the hydraulic power comes via 9 meter hoses from another machine , everything in the vicinity gets bombarded with rock chips , water spray , dust , oil and diesel fumes.

we cannot run wires to the machine to run an hour meter because they wouldnt last a day before being ripped out or smashed to bits.

what i want to measure is hydraulic runtime so we change filters when they are due , and so we can keep a tally of bearing hours on a drive motor also attached to the same circuit.

we cant use the hourmeter on the machine providing hydraulic power because they are moved and swapped around and other machines put in their place to provide the hydraulic power , so we would not have accurate figures on true runtime for this particular equipment

Its not prime power source "on time" that i want to measure , they have their own hourmeter already but as i mentioned , the prime power source will be moved and others put in their place to run the machine , so the hourmeter has to be built in to my machine.

pressure "on time" or flow " on time" is exactly what i need to measure :)

thanks for your sensible questions , sorry for being vague in detail but i cant give away too much information for IP reasons

have a nice day.

This is to keep track of filter intervals?

Suggestion #1: Buy a cheap differential pressure switch for your filters. The pressure switch will trip when service is needed. These are what we use on our Rock crushing equipment, and have worked flawlessly for decades.

I've designed and built Rock crushing units (The hydraulic's) for use all over the world, and no one has ever wanted an hour meter based on flow or pressure on their aux units, the PM indicators have always been enough. Interesting, maybe something I'll consider for next time. Thank you for the thought.

Suggestion #2: Do what others have said, Buy a cheap pressure switch (I've seen many on the net for $10-$30USD up to 3000psi), and hook it to an hour meter with some batteries. This will be your easiest solution. If you are dead set on having it all housed inside one case, I'm not aware of anything on the market. I don't think there is a whole lot of market demand for the device you are after.

FYI: Doing PM's based on runtime alone can end up being very costly, I have found that the best way to keep equipment alive and well is to actually do fluid samples at regular intervals. You will know when components are failing far before they clog a filter or destroy a pump. Samples can be as inexpensive as $25 to send to a lab, and they will tell you the exact makeup of your oil, your additives,any contamination, acid levels, etc etc etc. And make absolute sure you have at LEAST a visual differential indicator on every filter.

Its not just for filter intervals , though that is an important part of it.

We also need to keep a record of bearing hours in a $ 29,000 drive motor , if we know that they give 4300 hours then we will happily replace them at 3000 hours before they start spitting metal particulates and damaging the motor internals as has happened previously.

We initially used pressure differential switches on the filter housings but found they pop prematurely , probably from a flow or pressure spike , despite both filter and indicator being under the manufacturers specs .

We also do oil samples on the power source at every 500 hours but thats a bit of a sore point worthy of another post here as we had doubts about the reliability of the oil reports coming back from the "global industry name" and did a little field testing of our own by putting dirt and metal filings into some oil samples we sent away. Lo and behold the reports came back clean. This is a matter currently under *aggressive review* by management with several options being considered .

The filters i have built in to my machines are Stauff brand , rated at 240 litres/min for this oil type and we run a flow rate of 200 litres/min

I would change to a bigger filter housing but these ones are the biggest i can fit into the available space.

maybe i need to change to a different make of PD switch instead of the OEM ?

I could fit both a pressure differential switch " clogging indicator " and also an hourmeter i guess , the hourmeter is still essential for PM of other associated components too

If i dont get a reply from the specialists i have emailed i will build these myself .

I was hoping to get one off the shelf thats been proven to be reliable but so far it doesnt appear to be out there.

Price is not the issue , i dont care if it costs $ 39 or $390 but higher price is not always a guarantee of quality so i wont discount " cheap items " in my search.

I will have to use a pressure switch that is rated up to 375 bar plus safety factor but i did find at least one supplier who does them , so the configuration will be pressure switch encapsulated with its wiring ( soldered joints , not clip connectors ) in the same box as the hourmeter , probably with a sandwich layer of silicon around the hourmeter for a vibration damper , and a small bulkhead mount hydraulic bush that is fixed to the box so the pressure switch cant be damaged or dislodged by the hose being twisted or overtightened.

Thanks for all your thoughts above , they are all good input.

best wishes people.

:)

Oil sample laboratories are hit and miss, I have found this out first hand. There are quite a few companies out there who more or less offer a scam service. I have tried many companies, and have come to the conclusion that it's customer beware... do the research. The #1 lab in my book is Polaris Labs, who have been the best company to deal with, and their Lab is 100% reliable. I'm a extremely happy customer of theirs, and would strongly suggest using them for future oil sampling needs.

You might be surprised how much information can be obtained from a proper oil analysis.

As far as a off the shelf plug in unit for your hour-meter, I would be happy to design/fabricate and sell you a unit (that's what I do). I doubt you would come in financially ahead VS doing it yourself, but you might save time/frustration, and We would assume the liability for the unit. If you would like a quote for an all-in-one self contained unit, shoot me a PM and we can get the quoting process started.

Good luck!

Ohh.. and if you are tripping your differential switches prematurely with spikes, there is something greater in your systems that need attention. If your filter elements are seeing differential spikes above that of what the manufacturer has given, you run the risk of literally ripping tiny holes in your filter media, which would result a filter element that appears to be working, but is allowing many large particles to pass unfiltered. This is a serious problem, and needs to be looked into further. If the system was designed correctly from the ground up you should NEVER see spikes in your return line in excess of the setting on the pressure switch (or filter manufacturer ratings).

I know from first hand experience, from many customers who do regular PM's based on hours, that a TON of money can easily be wasted with this approach. It's considered the Blind man's approach to maintenance. The oil WILL tell you when components are about to fail, if you know how to read the test report (given that it's from a reliable lab).

I have seen so many pumps/motors come through our repair shop for an hour based PM rebuild that were almost like new (I'm talking about $30k to $230k pumps). The customer has a Rigid PM schedule, and wants the pumps rebuilt at certain intervals, sometimes we can talk them out of it, as the pump is in perfect condition, but much of the time, it gets rebuilt anyway, at a cost of anywhere from 8k-60k per pump. We see this time and time again when the maintenance blindly relies on runtime hours to PM equipment.

On the other hand, we also see pumps fail well before their PM due to other factors in the system, which typically involve another component upstream that is failing, or more likely than not, it's the oil itself.

The runtime hours are a very good guide, and I have no hesitation that installing the meters will be of great value to you and your company, but please just be aware that hours-of-use in no sense dictate the condition of the equipment, only either a disassembly/eval or an oil sample will tell you that for sure.

Don't dump $$ down the drains like I see all the time, It's just depressing.

Hope it all works well for you!

Oil is the heart/blood/soul of a hydraulic system... It's means everything.

The filters are on the pressure side of my machine to protect the expensive motor

The hydraulic power source has a return filter , and most of them have a pressure filter too , but not all.

i agree regarding the pressure spikes , early on we had one filter burst issue , then changed to high burst spec filters ( 210 bar burst rating versus 30 bar burst on the standard one)

I think after our conversations here i need to revisit the filter clogging indicators and get those to a reliable state , plus fit hourmeters as well.

The problem is that sometimes we dont have control over the state of the hydraulic power source , they could sometimes be subcontracted units that may not have ideal state of cleanliness of filters or oil , and sometimes the flow control rate could be out of adjustment , now this goes against the grain of what you and I are trained to do , but its a factor the client understands and its built in to their cost expectations , if there is a hydraulic catastrophe and i have done everything possible to eliminate risk then the price is paid by the client and we all move on.

This is the engineering industry , we build things that have a relationship to human behavioural dynamics in all its forms and manifestations.

:)

okay . work awaits .

have a good day gentlemen

$ 39 each folks

this is similar to what i want , but it has a drawback.

it is activated by vibration so it will register runtime if there is other machines working nearby such as rockbreakers

notice its size , very compact at about 2 inches long 1 1/4 high and 2 inches deep and has a built in battery that will last for 4 - 5 years

i need to know runtime hours of each machine for hydraulic servicing purposes so i think hydraulic pressure detection for activation would be more accurate .

Oh. Now I get it. Like a pressure activated, battery powered, Hobbs meter, that can be set up with an in line pressure switch. Too expensive?

i emailed Hobbs and Honeywell ( and many others ) last week but no response yet

i am aware they have separate pressure switches which can be Teed in to a hydraulic fitting and promptly replaced with a plug when their plastic top gets broken by a service mechanic the same week , or the wiring connection gets compromised by water ingress and nobody notices that the hourmeter has not moved in a two month period .

If they had a pressure switch with an all steel body and milspec seals on the wires that could work . YES.

Or we run a small hydraulic hose in to a protective sealed steel box where the pressure switch , encapsulated wiring and self powered hour meter are located . that could work . YES

but i would prefer to buy one off the shelf that has the pressure switch , wiring , internal battery and hourmeter all built in , so i dont have to spend 4 - 6 hours making and testing it.

If i have 6 months of manufacturing contracts in front of me the sensible option is to buy a component part that is self contained proven and tested and bolt it inside these machines with one 1/4" hydraulic hose to Tee in to a fitting.

:)

Maybe we're over thinking this.

I just had another thought. Why use hydraulic pressure to activate the hour meter at all?

Isn't the hydraulic flow started by some type of existing lever, switch, or valve, and shut off by same?

Why not tie it into that?

Just a thought.

thanks but the hydraulic flow is started by a machine which is 9 meters away

that machine could be removed and swapped with another of the same type by guys with no finesse who are likely to be covered in mud , grease , oil , on top of the fact there is rock chip and water spray being thrown around.

If we tried to run conduit and cabling with the hydraulic hoses they simply would not last.

the hour meter needs to be inside this equipment , and there is already a limit on free space , the whole unit would need to be smaller than a fist. ( which i know can easily be done )

thanks for replies peepil