Neometrix / Oil Purification Units / Oil Purification Unit / NMX-OPU-58

NMX-OPU-58 · ENGINEERED-TO-ORDER CLASS — SPECIFY · CONNECT · WARM · PURIFY · MEASURE · PROVE

Oil Purification Unit. Each contaminant has its own way out.

Name: Oil Purification Unit
Brand: Neometrix
SKU: NMX-OPU-58

A filter takes out what is solid. It cannot take out what the oil has dissolved. Water and gas need a vacuum, and the finest soft contamination needs a different method again.

So the unit is built around three things: filtration for solids, vacuum dehydration for water and gas, and an electrostatic stage for the finest soft contamination.

Discuss an oil purification unit Capability note (PDF)

A single trolley-mounted oil purification unit: a compact welded frame of grey painted steel on four heavy rubber wheels with a tow handle, carrying a tall vertical cylindrical brushed stainless steel vacuum chamber with a bolted flat lid, two upright cylindrical grey filter housings with domed lids, a grey electric motor and pump low on the frame, black flexible hoses with stainless couplings joining them and a grey junction box, and no people

Fig · 01 — A trolley-mounted oil purification unit: a vacuum chamber, two filter housings, a pump and its hoses on one wheeled frame — illustrative render.

The solids

filtered outstage by stage

The water and gas

taken out under vacuumfree, emulsified and dissolved

The fine soft products

an electrostatic stagewhere varnish is the problem

The heat

gentle and limitedheat helps, but it ages oil

Status

engineered to orderno purification unit claimed

ISO 9001ISO 14001ISO 4406 cleanliness code referenceIEC 60422 insulating oil reference

Overview

Why a filter alone is never the whole answer.

Because oil in service carries several kinds of contamination, and a filter stops only one of them.

Fig · 02 — The unit in one picture: the oil is drawn off, purified in stages and read against a target, then returned to its reservoir.

Each contaminant has its own way out.

What the unit is for

It keeps oil fit for use without changing it. The unit is connected to a reservoir, draws the oil off, cleans and dries it, and returns it, again and again, until the oil meets its target. It suits lubricating, hydraulic, turbine and insulating oil, and can be mobile or fixed.

Why each contaminant has its own way out

Oil in service carries solids, free water, emulsified water, dissolved water, dissolved gas, and the fine soft products of its own ageing. No single method removes them all. Each has its own way out.

Why a filter cannot take out dissolved water

Water dissolves in oil, and warm oil holds more of it. A particle filter has nothing to catch, so dissolved water passes straight through. If only the free water is taken out, the oil can still be wet, and when it cools some of the dissolved water comes out as free water again.

Why vacuum works

Lowering the pressure lowers the boiling point of water, so it leaves the oil as vapour at a temperature the oil can stand. The oil is spread over a large surface inside a vacuum chamber, which lets free, emulsified and dissolved water leave, and dissolved gas with it. The vapour is carried out, and condensed or vented.

Why the heat is gentle

Heat speeds the removal of water and thins the oil so that it flows through the stages. But heat also ages the oil, which is what the unit is there to prevent. So the heater has a set limit, and the limit comes from the oil, not from the heater.

Why an electrostatic stage is sometimes added

Oil in service forms very fine soft products, the first stage of varnish, that are too small and too soft for a filter to hold. An electrostatic stage charges them and collects them on a surface. It needs oil that is dry and does not conduct, so it follows the dehydration.

Why the reading decides

A unit that is not measured is not proved. Water is read by Karl Fischer titration or a moisture sensor, solids by a particle count, and fine soft products by a patch test, because a particle count cannot see them. The run ends when the reading says so, not when the clock does.

The method

Specify, connect, warm, purify, measure, and prove.

Six steps in a fixed order. The two shaded steps are the ones a quick order skips.

FIG · 02OIL PURIFICATION UNIT · SPECIFY / CONNECT / WARM / PURIFY / MEASURE / PROVE — EACH CONTAMINANT HAS ITS OWN WAY OUT

The step people underrate is the reading. A unit that has run for a set time has not been shown to have reached the target.

Fig · 03 — Three ways a purification lets you down: it uses a filter only, it dries the oil warm and lets it cool, and it stops by the clock — a drawing of the idea, with no values.

1 · Specify

The oil, its volume, its machine and the targets for solids, water and fine soft products are stated by the customer.

2 · Connect

The unit is joined to the reservoir by a loop that draws oil off and returns it, earthed, with hoses that keep the oil in a closed loop.

3 · Warm

The oil is warmed gently, to a set limit chosen so that the oil is not aged by the cleaning.

4 · Purify

The oil is circulated through the filter, the vacuum stage and, where needed, the fine stage, again and again.

5 · Measure

Water and particles are read during the run, and the run goes on until the reading reaches the target.

6 · Prove

The readings are kept, and handed over with the oil.

Work content

What the unit contains, element by element.

Read it as a checklist: a unit missing a row will pass oil that fails in service.

A single bank of two filter housings on a plain grey steel skid: two upright cylindrical grey painted steel housings with bolted domed lids, brushed stainless steel pipework with flanged joints joining their tops and bottoms, a stainless steel ball valve with a lever handle on each inlet, and two black flexible hoses with stainless couplings leaving the skid, and no people

Fig · 04 — The filter stage: two filter housings on a skid, with their inlet valves, pipework and hoses — illustrative render.

Element	What it does	What matters
Pump and drive	move the oil	a pump that suits the viscosity of the oil, and a drive that keeps the flow steady
Coarse and fine filters	take out solids	stages from coarse to fine, with indicators that show when an element is loaded
Heater	warms the oil	a heater with a low power density at its surface and a set limit, so that no oil is baked
Vacuum chamber	dries and degasses	a chamber that spreads the oil over a large surface under vacuum
Vacuum pump and condenser	carry the vapour away	a pump sized to the water load, and a condenser or trap that collects the water
Electrostatic stage	collects the fine soft products	a cell for dry, non-conducting oil, placed after the dehydration
Level and flow control	keep the chamber safe	level sensing and valves that stop oil being drawn into the vacuum pump
Instruments	read the oil	a moisture sensor, a particle counter and a sampling point on the loop
Controls	run the sequence	manual selectors or a PLC, with the temperature limit and the vacuum interlocked
Protection	keeps the run safe	a high-temperature trip, a low-level trip, pressure relief and an earthed frame
Hoses and connections	join the unit to the machine	hoses and couplings that match the oil and keep the loop closed
Frame	holds it together	a trolley or a fixed skid, with a drip tray under every joint
Testing & documentation	prove the unit first	a leak check, a vacuum check and a record the customer can inspect

The element that decides whether the unit does what it claims is the vacuum stage, because without it the unit cannot take out what the oil has dissolved.

Fig · 05 — One oil, three kinds of contaminant, three ways out: filtration, vacuum and an electrostatic stage.

Full specification — expand

System	A pump and drive; coarse and fine filters; a heater with a set limit; a vacuum chamber that spreads the oil over a large surface; a vacuum pump and a condenser or trap; an electrostatic stage for dry, non-conducting oil; level and flow control that keeps oil out of the vacuum pump; a moisture sensor, a particle counter and a sampling point; manual or PLC controls with the temperature limit and the vacuum interlocked; a high-temperature trip, a low-level trip, pressure relief and an earthed frame; hoses and couplings that keep the loop closed; a trolley or a fixed skid; a written run plan; and testing and documentation before handover
The One Idea	Each contaminant has its own way out.
Why Each Contaminant Has Its Own Way Out	Oil in service carries solids, free water, emulsified water, dissolved water, dissolved gas and the fine soft products of its own ageing, and no single method removes them all
Why A Filter Cannot Take Out Dissolved Water	Water dissolves in oil and warm oil holds more of it, so a particle filter has nothing to catch and dissolved water passes straight through, and if only free water is taken out the oil can still be wet and the dissolved water comes out again as the oil cools
Why Vacuum Works	Lowering the pressure lowers the boiling point of water, so free, emulsified and dissolved water and dissolved gas leave the oil as vapour at a temperature the oil can stand, when the oil is spread over a large surface inside a vacuum chamber
Why The Heat Is Gentle	Heat speeds the removal of water and thins the oil, but heat also ages the oil, so the heater has a set limit that comes from the oil and not from the heater
Why An Electrostatic Stage Is Added	Oil in service forms very fine soft products, the first stage of varnish, that are too small and too soft for a filter to hold, and an electrostatic stage charges and collects them, but it needs dry, non-conducting oil and so follows the dehydration
Why The Reading Decides	Water is read by Karl Fischer titration or a moisture sensor, solids by a particle count and fine soft products by a patch test, and the run ends when the reading says so and not when the clock does
Standards	ISO 4406 is the public reference for the cleanliness code of solid particles in hydraulic fluid, and IEC 60422 for the supervision and maintenance of mineral insulating oil in service. This page prints none of their codes or limits, and no edition year: those come from the standard the customer names and from the customer's duty. Approval of an oil for return to service rests with the customer and the authority they name; none is claimed here
Configurations	A portable filter unit on a trolley that filters out solids, a vacuum purifier that warms the oil gently and dries it under vacuum, and an integrated unit with filters, a vacuum stage and a fine stage
Scope Boundary	This page is the oil purification unit. It is not a flushing rig, which cleans a hydraulic system with filtration, mainly before it enters service (see hydraulic flushing rig and mobile hydraulic flushing rig), not a lube oil console, which feeds oil to bearings (see lube oil console) and not a filter test bench, which tests the filters themselves (see hydraulic filter test bench). No certification is claimed here
Status	Neometrix has quoted against successive oil purification and filtration requirements, and no delivered oil purification unit is claimed.

Configurations

One method, three ways to build the unit.

The method, the record and the run-to-a-reading rule are shared. What changes is which of the three ways out the unit provides.

Portable filter unit

Pump, filters and hoses

A trolley that circulates the oil through coarse and fine filters, for solids and for free water that has settled out, with a sampling point on the loop.

Vacuum purifier

Heater, vacuum chamber and condenser

A unit that warms the oil gently and dries it under vacuum, taking out water and dissolved gas as well as solids, where the oil is wet and not only dirty.

Integrated unit

Filters, vacuum stage and fine stage

A unit that filters, dries under vacuum and then collects the finest soft products on an electrostatic stage, with moisture and particle readings taken on the loop.

Fig · 06 — Three ways to build the unit, one method: a portable filter unit, a vacuum purifier, or an integrated unit.

And the part that is not equipment at all, yet decides all three: the run plan. It fixes the targets for solids and water, the temperature limit, the readings to be taken and the date of the next run, and it is written from the oil and the machine, not from the unit.

Where it is used

Wherever oil has to stay fit for use, and be shown to be.

The common thread is oil that protects a machine only while it is clean and dry, and a reading that says so.

Turbine and gearbox oil

Where lubricating oil in a large machine picks up water and fine contamination and has to be conditioned while the machine stays in its place.

Hydraulic systems in service

Where the fluid of a working system is cleaned and dried on a schedule, without draining the system.

Insulating oil

Where the oil of a transformer is dried and degassed, because moisture and particles weaken its insulation.

New oil before first fill

Where oil that arrives in a drum is cleaned and dried before it goes into a machine, because new oil is not always clean enough.

Watch

See it in motion.

A short walkthrough video of the oil purification unit.

FAQ

Common questions.

Longer answers, for readers who want the reasoning.

Q · 01 What does an oil purification unit actually do?

It cleans and dries oil while the oil stays in its machine. The unit draws oil from the reservoir, passes it through filtration, a vacuum stage that takes out water and gas, and where needed an electrostatic stage for the finest soft contamination, and returns it to the reservoir. It takes contamination out. It does not make exhausted oil new, and it does not put back additives that have been used up.

Q · 02 Why can a filter not take out dissolved water?

Because dissolved water is not a particle. It is spread through the oil as individual molecules, and a particle filter has nothing to catch, so the water passes straight through. Warm oil holds more dissolved water than cool oil. That matters twice over: oil that looks clear can still be wet, and oil dried only of its free water while warm can show free water again when it cools. A filter is the right way out for solids, and it is the wrong way out for water that is dissolved.

Q · 03 How does vacuum dehydration work, and what are its limits?

The oil is warmed gently and spread over a large surface inside a chamber held under vacuum. Lowering the pressure lowers the boiling point of water, so the water, and any dissolved gas, leaves as vapour at a temperature the oil can stand. The vapour is drawn off and condensed or vented, and the dry oil is pumped out. The limits are real. How fast water leaves depends on the viscosity and temperature of the oil, on the form the water takes and on how much there is, and a large amount of free water is better separated first, by settling or by a coalescing stage, so that the vacuum stage is left with what remains.

Q · 04 When is an electrostatic stage worth having?

When the trouble is the finest soft products of ageing, the first stage of varnish, which are too small and too soft for a filter to hold. The stage charges them and collects them on a surface. It works on oil that is dry and does not conduct, which is why it follows the dehydration, and it does not replace the filter, because hard particles still go to the filter. Whether it is working is shown by a patch test, not by a particle count, because a particle count starts at a few micrometres and these products are far smaller. Temperature matters too, since the same products are more soluble when the oil is warm.

Q · 05 Is this the same as the flushing rig, lube oil console or filter test bench pages?

No, and the differences are worth stating precisely. The hydraulic flushing rig and mobile hydraulic flushing rig pages clean a hydraulic system with filtration, mainly before it enters service. The lube oil console page feeds oil to bearings, with its own filters on the way. The hydraulic filter test bench page tests the filters themselves. This page is the unit that purifies oil in service, and the one that takes out what a filter cannot. It does not replace any of them, and it does not claim what they claim a second time.

Q · 06 Has Neometrix built one of these?

We would rather answer this plainly than let a page imply otherwise. Neometrix has quoted against successive oil purification and filtration requirements, and no delivered oil purification unit is claimed. What stands behind the offer is adjacent: Neometrix engineers hydraulic flushing rigs (see the hydraulic flushing rig page), lubrication skids (see the lube oil console page) and benches that test hydraulic filters (see the hydraulic filter test bench page). The pumps, filter elements, vacuum pumps, instruments and electrostatic cells are catalogue items, bought in, not invented. What Neometrix engineers is the unit around them: the frame, the loop and valves, the vacuum chamber arrangement, the heater limit, the controls and protection, the procedure and the record. So the honest position is that the unit is engineered to order, the neighbouring disciplines are in the building, and the first unit of this exact kind will be built around the customer's own oil rather than taken off a shelf.

Q · 07 Which standards apply, and what can the unit not do?

ISO 4406 is the public reference for the cleanliness code of solid particles in hydraulic fluid, and IEC 60422 for the supervision and maintenance of mineral insulating oil in service. Water is read by Karl Fischer titration. This page prints none of their codes or limits, and no edition year: those come from the standard the customer names and from the customer's duty. The unit takes contamination out of oil and records the readings. It does not certify the oil or anything else: this page claims no certification or accreditation. No water, particle or temperature figure is printed here, and approval of an oil for return to service rests with the customer and the authority they name; none is claimed here.

Q · 08 What do you need from us to quote?

Six things, and most of them describe your oil rather than the unit. First, the oil: its kind, its volume and the machine it serves. Second, the contamination: what it carries, and the targets for solids, water and fine soft products. Third, the flow: how quickly the oil has to be cleaned. Fourth, the place: whether the unit is mobile or fixed, and the services available. Fifth, the instruments: what must be read, and how often. Sixth, the record: what you want kept with each run. From that we come back with a unit concept, a written run plan you can check, and a budgetary price.

The neighbouring oil-handling pages, and how they differ from this one.

Three neighbours: one flushes a system, one feeds oil to bearings, one tests filters.

↗ A flushing rig

Hydraulic Flushing Rig

A skid that flushes a hydraulic system clean with filtration, mainly before it enters service - it cleans the system, not the oil in service.

↗ A lubrication skid

Lube Oil Console

A skid that keeps a large machine's bearings supplied with oil - the purifier is what keeps that oil fit.

↗ A filter test bench

Hydraulic Filter Test Bench

A bench that tests hydraulic filters themselves - it proves the filter, where this page cleans the oil.

Browse all Neometrix product lines.

Get a quotation

Tell us the oil, the volume,
and the targets.

The projects desk replies within two working days with a unit concept, a written run plan you can check, and a budgetary quotation. Write to [email protected] or use the form.

Enquire — oil purification unit Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED-TO-ORDER CLASS — OIL PURIFICATION UNIT SPECIFY · CONNECT · WARM · PURIFY · MEASURE · PROVE — EACH CONTAMINANT HAS ITS OWN WAY OUT ENGINEERED IN NOIDA · INDIA