Dripworks Micro-Flow Valves: QC FAIL

We recently installed a Dripworks drip irrigation system for Mary’s garden and, of course, pre-assembled the emitter / dripline tubing, fittings, and supply / filter / plumbing for each of the beds in the Basement Shop. A few days after burying the main lines, plumbing the filter + pressure regulator, and plugging in half a dozen bed assemblies, Mary noticed some emitter tubes weren’t delivering any water and other beds seemed too dry.

N.B.: We bought everything directly from Dripworks. This is not counterfeit crap from a sketchy Amazon seller.

I cut the dripline just downstream of the Micro-Flow valve on a completely dry bed, whereupon no water emerged. Cutting the supply tube just upstream of the valve produced a jet squirting halfway along the bed. I tried and failed to blow air through the valve: it was completely blocked despite being in the “open” position. I installed another valve and the emitter tube started working properly.

I sat down at the kitchen table with a bag of unused valves and peered through them (the pix are through the microscope):

Dripworks valve - mostly open lumen
Dripworks valve – mostly open lumen

That’s one of the better-looking valves, with only a little mold flash in the lumen.

Partially occluded lumens were more typical:

Dripworks valve - partially occluded lumen
Dripworks valve – partially occluded lumen

Quite a few were almost completely obstructed:

Dripworks valve - mostly occluded lumen
Dripworks valve – mostly occluded lumen

For lack of better instrumentation, I blew through the valves and sorted them by effort:

Dripworks valve - sorted by blockage
Dripworks valve – sorted by blockage

Two of the valves in the group on the left are completely blocked, with the others mostly blocked.

The middle group has enough mold flash to produce noticeable resistance to the air flow. I think water would have more trouble getting through, but the emitters would at least look like they’re delivering water.

The group on the right has mostly unblocked valves, with visible mold flash but little restriction.

I have no way to measure the actual water flow, so it’s entirely possible the QC spec allows considerable blockage while still delivering enough water to the emitters. More likely, the spec assumes a clear lumen and the mold flash is a total QC faceplant; it’s obviously not a controlled quantity.

Well, I can fix that:

Dripworks valve - drilling
Dripworks valve – drilling

That’s a 2.3 mm drill going straight through the valve body. I drilled the valves from both ends and blew out the swarf:

Dripworks valve - drill swarf
Dripworks valve – drill swarf

That produced twenty valves with clear lumens. Of course, the drill leaves a slightly rough interior surface, but it’s now much easier to blow air through them.

We hadn’t installed the driplines in two beds with three emitter tubes per bed. I cut out those six unused valves and sorted them by resistance:

Dripworks valve - six samples
Dripworks valve – six samples

Both of the valves on the left are blocked, the three on the right are mostly OK, and the one in the middle is partially blocked.

With two dozen repaired valves in hand, we returned to the garden, I cut 22 valves out of the installed driplines and replaced them under field conditions. Returning to the Basement Laboratory, I blew the water out (*), sorted them by resistance, and produced a similar distribution, albeit with no pictorial evidence. Although we have no immediate need for the used valves, they’re drilled out and ready for use.

In very round numbers, you should expect:

  • A third of Dripworks valves will pass (close to) the expected flow
  • A third will have a minor flow restriction
  • A quarter will have a severe flow restriction
  • One valve in ten will be completely blocked

Plan to drill out all the Micro-Flow valves before you assemble your driplines.

AFAICT, none of the other ¼ inch fittings we used have any interior flash, so it’s only a problem with the valves.

We are, as the saying goes, not amused.

(*) If you will eat a peck of dirt before you die, I’m well on my way.

9 thoughts on “Dripworks Micro-Flow Valves: QC FAIL

  1. I’m sure high-end brand name emitters would be a different story altogether but the price is no doubt a game changer. As for eating dirt … not that big of deal (mom always said it would give you worms) but the occasional grain of sand on the other hand can ruin a good salad. That familiar explosive repercussion that makes you stop chewing in fear of a second event.

    1. AFAICT, Dripworks is one of the Names, but they do get their hardware from elsewhere. This was another data point for my “spending more on stuff may not produce better stuff” cynicism, though.

  2. I’ve used tons of these from Dripworks over a few years now, never had this problem. I think these are Irritec branded valves. They are a pretty simple mechanism, it’s just an extruded piece of plastic attached to the knob. It’s difficult to remove the knob and “valve”, but it just pulls straight out. Nonetheless, I have 50 more on order (hopefully they ship it, it’s been a bit) and am hoping they don’t feature this problem. That’s pretty poor QC and should have been totally obvious to the assembler. Thanks for the repair tip, just in case, though.

    1. Definitely peer through the bores of those valves before you connect them!

      Mary wrote a scathing review which never appeared, so their problem may be worse than we thought.

      1. I got my shipment of these micro-valves. I can definitely confirm I also received several completely occluded micro valves, just as you did this year. I plan to go through them, determine the failures and ask for a future credit or replacement, at their expense. Then I’ll do a failure analysis (I’m an engineer) to figure out exactly what failed during the manufacturing process. It is disappointing they would immediately dismiss verifiable feedback on a product they are actively selling that clearly has a current QC defect.

        1. Now, that’s interesting!

          They must be working their way through an entire shipping container of duds.

          Feel free to aim them here for more evidence, as if they don’t have enough already.

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