Are All Valves Created Equal?

TeamTuff Compares Membrane and Lip/Duckbill Valves for Breast Pumps


Did you know that all breast pumps have a valve(s)? And that it’s probably the most important part of the pump?

That’s because it’s replaceable and without it, your pump won’t work. As valves wear, your suction suffers – which you might have learned the hard way.


That said, do you know what the valves look like?


Membrane valve on the left and one-way/duckbill valve on the right.

At Rumble Tuff, we manufacture both main types of valves for our pumps because there are pros and cons to both types and we have found that successful pumping means more options. Just like we don’t all wear the same bras or prefer the same ice cream, our nipples, breast tissue and breast anatomy is different. The pumping journey encompasses a great deal of medical/postpartum territory and that doesn't mean everything stays equal. And, our bodies are different with different pregnancies.

TeamTuff Tip: What works for your friend is often about as useful to you as what bra she prefers. While there are some generalizations that most pumping moms agree with, we are all individuals, and you might find that you prefer one style over another.

First, a primer on how the valves work:

  1. As the vacuum is applied (either the motor creates the “suck” or if you are hand pumping you move the lever) the valve needs to close completely. That’s so your nipple can be the only moving piece in the system and get pulled into the shield.

  2. Your nipple stretches and sprays milk. That’s where the “drop zone” is, and the most milk is removed. If your valve doesn’t close completely then not enough suction remains (because it’s all leaking out the open valve) and your nipple doesn’t get the full amount of vacuum you selected with your pump options.

  3. The pump cycle ends and without the vacuum being applied, the valve relaxes. Milk drops out because of gravity and your nipple returns to home base.

  4. Another pump cycle starts and the valve closes again. Rinse, repeat, over and over.

  5. The slower the pump cycle the more time your nipple spends in the “drop zone” and generally the more efficiently milk is removed. Like all things breast pumping, your mileage may vary and you should try combinations to see what is most comfortable and efficient for you. But the longer the cycle (the longer the nipple is in the “drop zone”) and the higher the suction, the more wear on the valves. This is why we suggest replacing as often as once a month, but valve wear depends entirely on use and care.

  6. Speaking of washing – wash your valves by hand and do it carefully. They tear easily. Don’t brush them or abrade them, but make sure they are clean by running hot soapy water through them or boiling then checking for residue.


TeamTuff breaks down the differences:

  • Lip valves are also called duckbill valves – depends on the manufacturer. They are the traditional, older style of valve. A few years ago membrane valves became more standard but you can find both styles on Amazon, typically.

  • Valves are not necessarily interchangeable brand to brand or even pump to pump even though they look the same and even fit the opening. Remember, your valve is one of the most important parts of the suction equation and you should always buy genuine parts for your pump to avoid injury. Generic valves can fit the opening but can be different than what the manufacturer intends. Meaning you are getting suction (and possibly other suction related pump features) that are out of the expected range for the pump. Breast pumps are medical devices and just like you wouldn’t buy a different manufacturer's piece for a ventilator/respirator/CPAP and hope it works out, you should always use genuine manufacturer parts on your breast pump. Your nipples will thank you and you could avoid days of trying to fix a supply problem that never existed -- it was just a valve/pump set issue.

  • Users report that lip valves can trap more milk/moisture in the tubing of open-system pumps. This may be one reason for the global switch in styles a few years ago. All Rumble Tuff pumps are closed-system so this is not an issue. But if you are using an open-system pump be aware of this if you decide to experiment, especially if you already struggle with milk/moisture in the tubing and pump.

  • When you are troubleshooting, it’s much easier to see if a duckbill valve is working compared to the membrane style. That’s because a good lip valve will pucker up and tighten up every time vacuum is applied and it’s easy to see valve wear. However, it can be very hard to see a small tear in a lip valve, so if you experience a loss of suction try a new valve to see if there’s an improvement.

  • Many moms report that the duckbill-style valves are easier to remove. That’s why Rumble Tuff makes our membrane valves with an extra long “handle”. Especially when coated with fatty newborn milk, those things are slippery! Did you know that we also have a “safety button” that keeps your membrane attached to the body while you wash it?

  • Some users say that they think the duckbill style makes more noise. We don’t find that with Rumble Tuff pumps and our valves, but it could be part of that generic situation we spoke of earlier. Only use genuine manufacturer parts in your breast pump. If using a different style causes noises like squeaking or honking, your pump might not be compatible with the valve. Don’t injure yourself or your pump by using generic parts.

  • If you are using a membrane valve, there is a correct installation position. That’s because the flap, or membrane, on the membrane-style valve is pushed open when the vacuum/suction stops, and the milk falls through. The flap doesn’t close as efficiently in other install positions and can get hung open, reducing your total suction. When putting your pieces together before using your pump be sure to push down on the membrane well to make sure it’s seated/shut well. If you’re having trouble with suction, do that again to make sure the membrane is making a tight seal.

  • Lip valves do produce slightly more suction. If you have very stretchy tissue that has a tendency to creep deeper and deeper in the tunnel as you pump, you should pay close attention if you switch styles. Some users report the pump “feeling” different with different styles of valves as well. Rumble Tuff pumps have our unique waveform that holds your nipple in the “drop zone” which might heighten the sensation difference for some users.

TeamTuff Tip: If you feel like your pump is losing suction, or you notice a drop in output, check your valves. They are, by far, the most likely culprit. If you use your pump with high suction frequently you will need to replace them faster than someone who uses low suction. We recommend changing your valves as often as once a month. Set a note on your calendar to check all your pump parts for wear at the 1st of the month so you aren’t left without spare parts. Your insurance may provide spare parts – check with the medical supply company where you got your pump.


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865 N 1430 W Orem, UT 84057
801-609-8168 or 1-855-228-8388
customerservice@rumbletuff.com