DFE: Testing Filters Under Real-Life Conditions (Part 4 of 4)

Posted by Jim Harlan on Tue, Jul. 18, 2017

Throughout the first three entries in this series (find parts one, two and three), we've discussed the difference in two filter element testing methods, ISO16889 and DFE. We've also illustrated how many elements fall short of their stated beta ratio under dynamic flow conditions. Today we'll wrap it up with simulated cold-start tests.

DFE Multi-Pass: Cold Start Contamination Retention

Once the element has captured enough contaminant to reach approximately 90% of the terminal ΔP (dirty filter indicator setting), the main flow goes to zero and the injection system is turned off for a short dwell period. Then the main flow goes to maximum element rated flow accompanied by real-time particle count to measure retention efficiency of the contaminant loaded element. The dynamic duty cycle is repeated to further monitor the retention efficiency of the filter element after a restart.

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Topics: ISO 16889, case study, filter performance, filter elements

DFE: Testing Filters Under Real-Life Conditions (Part 3 of 4)

Posted by Jim Harlan on Tue, Jul. 11, 2017

Last week we covered the differences between the ISO16889 Filter Test Procedure and the DFE Filter Test Procedure. This week we illustrate the difference between elements engineered to retain particles during dynamic flow conditions and those that are engineered only to pass the ISO16889 test. (Looking for previous posts? Find parts one, two and four.)

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Topics: ISO 16889, case study, filter performance, filter elements

DFE: Testing Filters Under Real-Life Conditions (Part 2 of 4)

Posted by Jim Harlan on Tue, Jun. 27, 2017

Last week, in part one, we briefly discussed how filter elements are rated by manufacturers. This week we're discussing the industry standard ISO16889 multi-pass test and Hy-Pro's standard, the DFE test. (Already read part two? Read parts three and four.)

Current Filter Performance Testing Methods

To understand the need for DFE, it is important to understand how filters are currently tested and validated. Manufacturers use the industry standard ISO16889 multi-pass test to rate filter efficiency and dirt-holding capacity of filter elements under ideal lab conditions.

Figure 1 depicts the test circuit where hydraulic fluid is circulated at a constant flow rate in a closed-loop system with on-line particle counters before and after the test filter. Contaminated fluid is added to the system at a constant rate. Small amounts of fluid are removed before and after the filter for particle counting to calculate the filter efficiency (capture). The capture efficiency is expressed as the Filtration Ratio (Beta) which is the relationship between the number of particles greater than and equal to a specified size (Xμ[c]) counted before and after the filter. In real-world terms, this test is the equivalent of testing a filter in an off-line kidney loop rather than replicating an actual hydraulic or lube system. It’s basically a filter cart test.

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Topics: ISO 16889, case study, filter performance, filter elements

DFE: Testing Filters Under Real-Life Conditions (Part 1 of 4)

Posted by Jim Harlan on Tue, Jun. 20, 2017

The Dynamic Filtration Efficiency (DFE) Test is Hy-Pro's standard for testing filter elements. Throughout this four-part series  (find parts two, three and four) we'll discuss what it is, why it matters and why elements engineered with this test in mind outperform others in real-life applications.

First, let's start with the basics.

Why are filters used? How are they rated?

All hydraulic and lube systems have a critical contamination tolerance level that is often defined by -- but not limited to -- the most sensitive system component such as servo valves or high-speed journal bearings. Defining the ISO fluid cleanliness code upper limit is a function of component sensitivity, safety, system criticality and ultimately getting the most out of hydraulic and lube assets.

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Topics: ISO 16889, case study, filter performance, filter elements

Hy-Pro's DFE Rated Filter Element vs. Brand X Filter Element

Posted by Jim Harlan on Wed, Jun. 07, 2017

The Problem: Too Much Filter-Related Downtime

A paper machine was experiencing excessive downtime as maintenance personnel was frequently servicing a Brand X filter element installed on the lube system. The element would reach terminal ∆P and require replacement every 8.5 days on average.

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Topics: contamination, DFE, filter comparison

How a Vacuum Dehydrator Prevented Bearing Failure and Unplanned Outages

Posted by Jim Harlan on Tue, May. 16, 2017

Saves >$15,000,000 by removing water and particulate from common reservoir lube oil.

The Application

In boiler water feed pump applications, water often finds its way into the oil lubricating the pump’s bearings. This was the scenario at a paper manufacturing facility that turned to Hy-Pro for help.

The Problem

In this application, the boiler water feed pump bearing lube system was combined with the facility’s steam turbine lube oil system. The water and the particulate contamination it was bringing with it were decreasing the fluid’s ability to lubricate the bearings and causing premature wear on the bearings.

The facility was attempting to remove free water with water absorbing filters (changed weekly) but the rate of ingression was too high for the filters to be as effective as needed. And since absorbents only remove free water, the filter elements were unable to address the dissolved and emulsified water present in the oil. If the situation were to continue much longer, a premature replacement of the steam turbine and boiler feed pump bearings would be necessary outside of the scheduled maintenance periods. While possible, this solution would cost millions of dollars without addressing the root of the problem. 

 

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Topics: vacuum dehydrator, case study, lube oil, VUD

Preventing Varnish in AW Hydraulic Oil

Posted by Jim Harlan on Tue, May. 02, 2017

Saves >$200K/year by reducing downtime, defective units, idle labor and oil costs.

The Application

During the manufacturing process of refrigerators, the organic compound isocyanate is hydraulically injected into the body of the appliance to improve insulation. After injection, the chemical transforms from liquid to foam, expanding to fill vacant areas completely. 

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Topics: varnish, SVR, hydraulic oil

When a Pump Fails, the Whole System Fails: Hydraulic Pump Reliability

Posted by Jim Harlan on Tue, Feb. 21, 2017

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.

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Topics: hydraulic fluid, ISO 4406, breathers, case study, hydraulic pump

Hy-Pro vs. Brand X Filters in a Single-Pass Fluid Transfer

Posted by Jim Harlan on Tue, Feb. 07, 2017

The Problem

Today’s oil suppliers are often required to provide fluid at or below a specified ISO Cleanliness Code. One such supplier was experiencing short filter element life (15 days) on the system (7 element multi-round housing) used to achieve the required ISO Cleanliness Code of 18/16/13 in a single pass as 15W-40 oil is transferred from their bulk storage tanks to tanker trucks for delivery.

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Topics: ISO 4406, filtration, breathers, offline filtration, case study, fluid transfer, DFE

High Surface Finish Defects at an Automotive Stamping Plant

Posted by Jim Harlan on Tue, Jan. 03, 2017

The Application

An automotive stamping plant operating large presses to produce body panels was experiencing high surface finish defect scrap. Lubricating oil contamination was causing surface imperfections that would be visible after painting.

The Problem

The uncoiler/washer lube oil system was protected by an off-line filtration system fitted with CJC stacked disc cellulose media filter inserts (elements). Oil analysis revealed an operating ISO code of 23/19/11. Patch analysis showed cellulose fibers were shedding into the oil from the filter inserts downstream of the filtration system.

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Topics: ISO 4406, offline filtration, case study, fluid transfer, filters, DFE

   

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