Deepsea Breast Pump Flange

A breast pump flange, also called a breast shield, is the funnel-shaped cup that fits against the breast during pumping. The narrow tunnel of the funnel fits over the nipple and creates the suction seal that draws milk from the breast into the collection bottle. Flange size refers to the inner tunnel diameter, which must match the nipple diameter for the suction to work efficiently and comfortably. If the tunnel is too small, the nipple compresses against the walls during suction, causing pain and restricting milk flow. If the tunnel is too large, too much areola is pulled in, reducing suction efficiency at the nipple and causing swelling. The correct size allows the nipple to move freely in the tunnel with 1 to 3mm of clearance.

Measure your nipple diameter in millimetres at the widest point of the nipple base, not including the surrounding areola tissue. Add 1 to 3mm to this measurement to find your ideal flange tunnel diameter. The nipple should move freely inside the tunnel during suction without touching the walls, and only a small amount of areola should be drawn in at the base. If your nipple measures approximately 14 to 16mm at the base, start with the 17mm Deepsea flange. If it measures 17 to 18mm, try the 19mm. If it measures 19 to 20mm, the 21mm is the correct starting point. Nipple size can also change slightly during the breastfeeding period as tissue responds to repeated suction.

Using a flange that is too small causes the nipple to rub against the tunnel walls during suction, creating friction that leads to soreness, redness, and nipple pain after sessions. It also compresses the milk ducts during suction, reducing milk flow and overall output per session. Using a flange that is too large draws excessive areola tissue into the tunnel, creating a false suction seal that misses the nipple ducts and causes swelling or bruising at the nipple base. Both situations result in uncomfortable sessions and lower milk output than the pump is capable of delivering with the correct fit. Switching to the correct size resolves both problems immediately.

Replace your breast pump flange when the material shows any visible discolouration, cracking, deformation, or loss of the smooth surface finish that creates the suction seal against the breast. Flanges are direct-contact parts that should be replaced periodically regardless of visible wear, as repeated sterilisation and daily use degrade the material quality over time, even without obvious damage. If you notice a gradual decline in suction quality from your pump that is not explained by battery charge or valve condition, the flange is often the cause. Also, replace if your nipple size changes during breastfeeding and the current size no longer fits with 1 to 3mm of clearance.

The Deepsea Breast Pump Flange is designed for use with the Deepsea Prime Electric Breast Pump and Deepsea Prime Manual Breast Pump. Flange compatibility depends on the connector design of the pump, which varies between brands and models. Using a flange designed for one pump with a different brand pump may result in an improper seal, reduced suction transfer, or physical incompatibility at the connector. If you are using a non-Deepsea pump and looking for a replacement flange, confirm compatibility with your pump manufacturer before purchasing. For Deepsea pump users, this flange is the correct direct-fit replacement and size upgrade option across all three available sizes.