Filter Supplies Blog
October 31, 2019

Anti Drain Back Valves, Bypass Valves & Micron Ratings in Aftermarket Filters

When comparing filter brands a lot of the questions we get come down to anti-drain back valves, bypass valves and micron ratings. There are some common misconceptions around each of these components and ratings which can be cleared up pretty swiftly.

Every filter produced for an original equipment application is formulated very early in that machine’s life with the filter company that produces the initial fit filters. As a guide, here are the manufacturers involved and who they produce for:

All the various perceived operating parameters of the relevant machine, be it a compactor, car, motorbike or dump truck are taken into account in the formulation of the filter. After a process taking many years, a set of figures are created for the filter – burst pressure, dirt holding capacity, nominal micron rating, absolute micron rating etc.

It normally takes at least 12 months for any other manufacturer to bring an aftermarket equivalent of that filter to market.

How do other manufacturers bring an equivalent filter to market?

How this occurs is really simple. The other manufacturers test the original filter then reverse engineer it.

Every manufacturer that we sell does this and their products conform to the relevant international standard. For every component in a filter there is a set of numbers for how that part should perform. For example, the Japanese Industrial Standard (JIS) for automotive oil spin on oil filter anti drain valves dictates the following performance in testing:

  • Drain Back Test: Less than 50ml over a 6 hour period
  • Pressure Loss Test: Less than 30kPa (10L/min)

That gives you some idea of how each component has to meet a certain performance standard.

Micron ratings

Micron ratings are easily tested and matched by the various aftermarket manufacturers. There is only a handful of reputable oil filter media manufacturers in the world. No internal combustion engine oil filter manufacturer makes its own oil filter media. Not one.

Once a manufacturer has tested the micron rating and performance of the original equipment (OE) element it’s just a matter of putting together all the relevant conforming components and selecting the right media from its supplier. In most cases, this is exactly the same supplier as the OE element. We wish we could show you pictures of the thousands of rolls of media we have seen in all the filter factories we’ve toured over the years that come from the exact same supplier.

What does this all boil down to?

The large international manufacturers we stock produce equivalent filters to meet or exceed the performance of the original equipment filter. They are designed to operate in exactly the same manner as the filter that the manufacturer will sell you. That’s in all areas of performance. (By the way, we’ve seen all the relevant test results but unfortunately we’re bound by non-disclosure agreements.)

We stand by every filter we sell – if we wouldn’t use it on our own vehicles and equipment we don’t ask you to use it on yours.

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