Everything you Need to Know about Breast Pump Parts

Everything you Need to Know about Breast Pump Parts

Jul 14 , 2020


Megan McDonough

For many nursing moms, investing in a breast pump is a must. You may be heading back to work or, perhaps you are looking for more flexibility in terms of when and where you pump. There are several factors to consider here, such as whether or not it’s lightweight and durable, but before that, let’s do a rundown of the pump's main parts. 

From flanges to valves, here’s what to expect from your breast pump. Don’t forget, our Lilu Massage Bra is not a pump, but it works with your pump to make breast pumping more efficient. Think of it as your pump's new sidekick.

Breast shields (flanges)

A flange, or breast shield, is the part of the breast pump that positions directly over the nipple and forms a vacuum seal over the areola, drawing your nipple into the tunnel for milk extraction. When you’re pumping, the flange is what secures over the breast for suction and release. 

Flanges are essential for pumping, so you’ll want to make sure you get one that fits your nipple just right. Most pumps come with flanges to fit the 24mm size. You can test this out to see if it works for you and if not, many companies sell sizes ranging from 21mm - 36mm. 

Pumping Tip: Flanges come in different sizes! A flange that is not properly sized can make it difficult and uncomfortable to pump enough milk. There should be some wiggle room between the nipple and the flange, enough so your nipple doesn’t rub tightly against the flange, but not so much that the areola is drawn inside the flange. Ideally the flange should be ~2mm wider than your nipple after a pumping session. 

Breast pump valves

Breast pump valves, as well as backflow protector membranes (see below) are made of a flexible silicone material. This is partly because the valves stretch and release each time your breast pump sucks in, therefore creating the suction you feel when nursing your infant. 

Because of this stretching and releasing, valves will eventually wear down and become less efficient. For this reason, you’ll want to replace your breast pump valves on a regular basis. Of course, this depends on how often you pump but usually you will have a pretty good idea of when it’s time to get new valves because your milk output will decrease. 

Backflow protectors

As their name suggests, backflow protectors protect backflow from entering the breast pump motor. In short, they act as a physical barrier between your milk and the pump motor, as well as to ensure that your milk supply is sanitary. 

Similar to breast pump valves, your backflow protector diaphragms should be replaced regularly. How often depends on how frequently you pump. Spectra suggests replacing backflow protectors every 2-3 months if you pump once a day, and every 6-8 weeks if you pump more than once per day. Just keep an eye on this part and notice if it’s torn or damaged. 

To clean your backflow protectors, wash it in hot, soapy water and then let it air dry. Before use again, make sure the protectors are completely dry. 


The pump motor vacuums in the air that travels and is displaced through the tubes. A common misconception when you first see a breast pump is that the milk travels through the tubes, when that isn’t the case. 

The FDA also notes that it’s not necessary to clean breast pump tubing unless it comes in contact with breast milk. However, if there’s any condensation in the tubing after you’ve pumped, then make sure to dry the tubes. If you notice any milk in the tubes, you’ll want to replace them altogether, as mold can grow pretty quickly. 


This is the part of the breast pump that connects the tubing, breast shield, valve and. Membranes and milk storage containers to each other. Depending on what pump you buy, the connector might come attached to the breast shield; in other cases, it will be separate.

It’s totally up to you preference on which type you buy, but keep in mind that when the connector comes separate from the shield, it makes for easier cleaning.

Lilu is a Women’s Health company building tech-enabled devices to empower new moms. Our first product, the Lilu Massage Bra, mimics compression massage, so you can empty your breasts fully to establish, increase and maintain your milk supply. Pump up to 50% more milk each session, all while going hands-free.
Lilu Massage Bra with flanges

Lilu Massage Bra

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