--- title: Donaldson Hy-Pro Lube & Hydraulic Filtration Industry Blog | ISO 4406 description: ISO 4406 | Learn about hydraulic fluid, lube oil, diesel fuel and industrial fluid contamination, filtration and conditioning on the Donaldson Hy-Pro blog. --- [![Donaldson Hy-Pro Logo_White](https://www.hyprofiltration.com/hs-fs/hubfs/Hy-Pro%20Logos/Donaldson%20Hy-Pro%20Logo_White.png?width=591&height=265&name=Donaldson%20Hy-Pro%20Logo_White.png) ![Donaldson Hy-Pro Logo 2](https://www.hyprofiltration.com/hs-fs/hubfs/Hy-Pro%20Logos/Donaldson%20Hy-Pro%20Logo%202.png?width=584&height=262&name=Donaldson%20Hy-Pro%20Logo%202.png) ](https://www.hyprofiltration.com) [**](https://www.hyprofiltration.com/blog/topic/iso-4406#tmpmodule_1568675152246189) [![Distributors](https://no-cache.hubspot.com/cta/default/170326/6a993b6f-f737-4a22-8a35-a45c4da5c3b4.png)](https://cta-redirect.hubspot.com/cta/redirect/170326/6a993b6f-f737-4a22-8a35-a45c4da5c3b4) ![ECATALOG](https://no-cache.hubspot.com/cta/default/170326/interactive-162302555948.png) ** ###### 3 min read ### [Getting to Know Demulsibility](https://www.hyprofiltration.com/blog/getting-to-know-demulsibility) By [Hy-Pro Marketing](https://www.hyprofiltration.com/blog/author/hy-pro-marketing) on Thu, Mar. 25, 2021 # Demulsibility ## What is Demulsibility? Demulsibility is the ability of oil to separate from water. Oil and water naturally separate because like molecules attract each other. Oil sticks with oil, water sticks with water. Oil is "hydrophobic", or "afraid of water," which is a benefit when it comes to fluids like turbine oil.  ###### Topics: [varnish in hydraulic oil](https://www.hyprofiltration.com/blog/topic/varnish-in-hydraulic-oil) [varnish in turbine oil](https://www.hyprofiltration.com/blog/topic/varnish-in-turbine-oil) [contamination](https://www.hyprofiltration.com/blog/topic/contamination) [water in oil](https://www.hyprofiltration.com/blog/topic/water-in-oil) [dirt](https://www.hyprofiltration.com/blog/topic/dirt) [Phosphate Ester](https://www.hyprofiltration.com/blog/topic/phosphate-ester) [diesel engine](https://www.hyprofiltration.com/blog/topic/diesel-engine) [maintenance](https://www.hyprofiltration.com/blog/topic/maintenance) [steel mills](https://www.hyprofiltration.com/blog/topic/steel-mills) [vacuum dehydration](https://www.hyprofiltration.com/blog/topic/vacuum-dehydration) [rolling mill lubricating oil](https://www.hyprofiltration.com/blog/topic/rolling-mill-lubricating-oil) [filter housing sizing](https://www.hyprofiltration.com/blog/topic/filter-housing-sizing) [micro-dieseling](https://www.hyprofiltration.com/blog/topic/micro-dieseling) [thermal event](https://www.hyprofiltration.com/blog/topic/thermal-event) [ISO 4406](https://www.hyprofiltration.com/blog/topic/iso-4406) [vacuum dehydrator](https://www.hyprofiltration.com/blog/topic/vacuum-dehydrator) [fluid samples](https://www.hyprofiltration.com/blog/topic/fluid-samples) [oil analysis](https://www.hyprofiltration.com/blog/topic/oil-analysis) [metal analysis](https://www.hyprofiltration.com/blog/topic/metal-analysis) [paper mill](https://www.hyprofiltration.com/blog/topic/paper-mill) [hydraulic pump](https://www.hyprofiltration.com/blog/topic/hydraulic-pump) [samples](https://www.hyprofiltration.com/blog/topic/samples) [COD](https://www.hyprofiltration.com/blog/topic/cod) [duplex low-pressure](https://www.hyprofiltration.com/blog/topic/duplex-low-pressure) [gearbox](https://www.hyprofiltration.com/blog/topic/gearbox) [contaminination](https://www.hyprofiltration.com/blog/topic/contaminination) [hydraulic](https://www.hyprofiltration.com/blog/topic/hydraulic) [duplex high-pressure](https://www.hyprofiltration.com/blog/topic/duplex-high-pressure) [cellulose media](https://www.hyprofiltration.com/blog/topic/cellulose-media) [filter elements](https://www.hyprofiltration.com/blog/topic/filter-elements) [filter comparison](https://www.hyprofiltration.com/blog/topic/filter-comparison) [aluminum refinery](https://www.hyprofiltration.com/blog/topic/aluminum-refinery) [lab](https://www.hyprofiltration.com/blog/topic/lab) ###### 3 min read ### [When a Pump Fails, the Whole System Fails: Hydraulic Pump Reliability](https://www.hyprofiltration.com/blog/hydraulic-pump-reliability) By [Hy-Pro Marketing](https://www.hyprofiltration.com/blog/author/hy-pro-marketing) on Tue, Feb. 21, 2017 [![](https://www.hyprofiltration.com/hubfs/images/Hydraulic-Pump.jpg) ](https://www.hyprofiltration.com/blog/hydraulic-pump-reliability) ## The Problem: Hydraulic Pump Failure  ## Pumps are the heart of hydraulic systems. When the pump fails, the entire system is down until the pump is operational again. This poses a serious threat to any operation relying on hydraulic systems for productivity. Recently, a hydraulic valve manufacturer was losing 25 pumps a year on their centralized hydraulic system at a cost of $2,440 each -- and that’s only the pump cost. When you account for maintenance resources, lost oil and lost production, each failure costs ~$25,320. ###### Topics: [hydraulic fluid](https://www.hyprofiltration.com/blog/topic/hydraulic-fluid) [ISO 4406](https://www.hyprofiltration.com/blog/topic/iso-4406) [breathers](https://www.hyprofiltration.com/blog/topic/breathers) [case study](https://www.hyprofiltration.com/blog/topic/case-study) [hydraulic pump](https://www.hyprofiltration.com/blog/topic/hydraulic-pump) ###### 2 min read ### [Hydraulic Valve Performance Test Stands and Clean Oil](https://www.hyprofiltration.com/blog/hydraulic-valve-performance-test-stands-clean-oil) By [Hy-Pro Marketing](https://www.hyprofiltration.com/blog/author/hy-pro-marketing) on Tue, Nov. 29, 2016 [![](https://www.hyprofiltration.com/hubfs/Hydraulic_Valve-681780-edited-2.png) ](https://www.hyprofiltration.com/blog/hydraulic-valve-performance-test-stands-clean-oil) ## The Application A hydraulic valve manufacturer required pristine fluid (< 14/12/9) to test flow across an 80-micron orifice on their test stand. Gross amounts of contamination in the fluid would skew the test results, invalidating any data collected. The system held 100 l (26.4 gal ) of ISO VG 32 fluid with a flow rate of 25 lpm (6.6 gpm ).Through observing the manufacturer’s sampling practices, discussing fluid handling best practices and interpreting their lab reports, three independent problems were identified: ###### Topics: [ISO 4406](https://www.hyprofiltration.com/blog/topic/iso-4406) [hydraulic valve](https://www.hyprofiltration.com/blog/topic/hydraulic-valve) [samples](https://www.hyprofiltration.com/blog/topic/samples) [hydraulic oil](https://www.hyprofiltration.com/blog/topic/hydraulic-oil) ###### 8 min read ### [ISO 4406: What Do Those Numbers Mean in the ISO Cleanliness Codes?](https://www.hyprofiltration.com/blog/bid/216397/iso-4406-what-do-those-numbers-mean-in-the-iso-cleanliness-codes) By [Hy-Pro Marketing](https://www.hyprofiltration.com/blog/author/hy-pro-marketing) on Mon, Oct. 08, 2012 [![](https://www.hyprofiltration.com/hs-fs/file-18430313-png/images/iso-resized-600.png) ](https://www.hyprofiltration.com/blog/bid/216397/iso-4406-what-do-those-numbers-mean-in-the-iso-cleanliness-codes) > ***Guest post today by Dan Helgerson. He is the Technical Editor of the ******[Fluid Power Journal](http://www.fluidpowerjournal.com/)***, where this article was originally published. We have been talking a lot about filtration here at the steel mill. My predecessor had done a remarkable job in educating by example, demonstrating the need for good control of the fluids in our hydraulic and lubrication systems. He had helped stop the leaks and had added well-thought-out filtration systems that have resulted in substantial savings and increased productivity. There is still a lot of work to be done and in pursuing that we have invited a number of vendors in, each offering an approach to getting and maintaining an acceptable fluid cleanliness level. The one thing that they all have brought to the table is a discussion of the **ISO Cleanliness code**. I was in a meeting with a group of managers when one vendor began to talk about the code. Being a Certified Fluid Power Accredited Instructor (AI), I immediately saw this as an obvious teaching moment, so I asked, “Does anyone here want to know what those numbers mean?” The answer was a quick and resounding, “No!” ###### Topics: [iso cleanliness codes](https://www.hyprofiltration.com/blog/topic/iso-cleanliness-codes) [ISO 4406](https://www.hyprofiltration.com/blog/topic/iso-4406) [All posts](https://www.hyprofiltration.com/blog/all) ### Featured ### Sign up for updates ## Have a Question for Donaldson Hy-Pro? 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