lostvape logo white
Vape cartridge 9-1

November 20, 2025 / Blog / By administrator

Leak-Proof Performance of vape cartridge: URSA V3’s Enhanced Sealing Design

Many e-cigarette users have encountered the problem of e-liquid vape cartridge leakage. 41% of users switch brands due to leakage, and on average, each user wastes 23% of their e-liquid annually. For many, leakage is not just a minor annoyance but a fatal flaw that leads them to abandon e-cigarettes completely. LostVape’s URSA Cartridge V3, a top-fill vape cartridge, solves this problem. Its enhanced sealing system provides up to 50% better leak prevention than standard cartridges. The intuitive top-fill design makes refilling easier and cleaner, while the robust sealing components firmly lock in the e-liquid. Whether you casually place it in your pocket, it’s bumping around in your gym bag, or it’s stored in a hot car, you don’t need to worry about leakage.

Causes of Vape Cartridge Leaks: Hidden Flaws in Standard Designs

The leading causes of leakage stem from predictable flaws that affect both standard bottom-fill and poorly sealed top-fill cartridges.

Firstly, the weakness of bottom-fill designs: Most inexpensive cartridges use a bottom-fill design, with the filling port close to the coil and airflow channel. This creates two key weaknesses: the sealing ring around the filling port and pressure buildup. Secondly, the use of inferior seals; cheap cartridges use thin, low-grade foam or plastic gaskets that age quickly, cracking, drying out, or losing elasticity after several refills. Worn gaskets directly lead to leaks.

Additionally, overfilling also poses a risk. The filling lines on standard vape cartridges are unclear, making it easy to overfill. Excess e-liquid seeps into the airflow channels, causing leaks when the cartridge is tilted or shaken. Furthermore, changes in temperature and pressure also pose a risk of leakage. E-cigarettes heat the cartridge, causing the e-liquid to expand. Standard cartridges lack effective pressure relief mechanisms, so the expanded e-liquid can leak from poorly sealed areas.

Causes of Vape Cartridge Leaks

The URSA V3 cartridge’s top-fill design is the foundation of leak prevention

The URSA V3 cartridge’s top-fill design is not just for convenience; it’s the first line of defence against leaks. Unlike bottom-filled coils, the URSA V3’s top-fill system places the filling port at the highest point of the coil, away from the coil, airflow, and seals:

Pressure-Free Filling: When filling from the top, air is naturally expelled through the airflow holes, preventing pressure buildup. Bottom-filled coils trap air, which forces e-liquid out of the seal when the coil is closed.

Single-Point Seal: The URSA V3 has only one filling port, while bottom-filled models have multiple potential leak points. Fewer leak points mean a lower risk of leakage.

No Need to Guess Fill Levels: The URSA v3’s top-fill design features a clearly marked maximum fill line for easy monitoring during filling. This effectively prevents overfilling, the most common leakage problem, as it accurately displays the amount of e-liquid the coil can hold.

Cleaner, more convenient refilling: The top-fill design prevents e-liquid from dripping onto the coil or base, reducing residue buildup and preventing seal damage over time.

Enhanced sealing components, URSA V3’s leak-proof performance improved by 50%

The URSA V3 filter features a top-fill design and a high-quality sealing component, offering 50% better leak-proof performance than standard filters. Every element of the sealing system is meticulously designed for durability, flexibility, and a tight fit.

Double-layer silicone gasket: Instead of a single thin foam gasket, the URSA V3 uses a 2mm-thick food-grade silicone gasket with bevelled edges. The inner layer seals the filling port, while the outer layer fits tightly against the e-liquid cap’s threads, forming a double leak-proof barrier. The silicone material is heat-resistant, e-liquid-resistant, and abrasion-resistant, maintaining its elasticity for over 50 refills.

Coil base seal: The coil is secured by a second silicone sealing ring, preventing e-liquid leakage from the coil connection point. Standard cartridges typically omit this sealing ring, relying solely on the coil’s press fit.

Airflow Valve Protection: The URSA V3 cartridge’s airflow valve is protected by a small silicone cap that only opens during inhalation. This prevents e-liquid from seeping into the airflow channel during storage or transport. These components work together to create completely leak-proof vape cartridges.

Enhanced sealing components, URSA V3's leak-proof performance improved by 50%

Real-World Leakage Test – URSA V3 vs. Standard Vape Cartridge

While lab testing is essential, real-world use is where the leak-proof performance truly shines. We conducted three rigorous real-world tests on the URSA Cartridge V3 and compared it to leading standard cartridges:

Test 1: Pocket/Pack Simulation

We filled 10 URSA V3 cartridges and 10 standard bottom-fill cartridges with 1.0 ml of menthol e-liquid, sealed them, and placed them in a canvas bag containing keys, a phone, and a wallet. We shook the bag for 30 minutes.

Results: 0 URSA Cartridge V3 cartridges leaked; 7 standard cartridges leaked, and e-liquid was visible on other items.

Test 2: Extreme Temperature

We stored 10 URSA V3 cartridges and 10 standard cartridges in a car for 8 hours.

Results: 1 URSA V3 cartridge had a small amount of e-liquid around the cap; 8 standard cartridges leaked severely, with e-liquid accumulating in the reservoir.

Test 3: Repeated Refilling

We refilled 5 URSA V3 cartridges and five standard cartridges 50 times each, storing them upright and on their sides between refills.

Results: All 5 URSA V3 cartridges did not leak; 4 standard cartridges began to leak after 15-20 refills.

A third-party testing company verified our test results, confirming that the URSA Cartridge V3 has a 52% lower leakage rate than standard cartridges in real-world use.

How can you maximise the leakproof performance of the URSA V3 cartridge?

Even with the URSA Cartridge V3’s industry-leading leak-proof design, adopting a few simple habits will ensure you never encounter leaks. Follow the maximum fill line. The URSA V3’s top-fill system has a clearly marked maximum fill line; never exceed this line. Even with the V3’s sealing function, overfilling is the only user error that can lead to leaks. Additionally, store it upright whenever possible. While the URSA V3 rarely leaks when stored on its side, upright storage keeps the e-liquid away from the flow valve and cap seal, maximising its lifespan.

Regular cleaning of the seal is also necessary. After every 10 refills, wipe the silicone seal with a dry cloth to remove any e-liquid residue. Residue buildup can damage the seal over time. Furthermore, avoid extreme temperatures. Do not leave the URSA Cartridge V3 in high or low temperatures for extended periods. Extreme temperatures can damage the seal and cause the e-liquid to expand/contract.

How to maximize the leak-proof performance of the URSA V3 cartridge

Leak-proof, Clean, and Reliable

Leaking shouldn’t be the norm for e-cigarettes. The URSA V3 cartridge features a top-fill design and an enhanced sealing assembly, eliminating the hassle, mess, and waste caused by leaks and delivering up to 50% improved leak-proof performance. Whether you’re commuting, working out, travelling, or in your daily life, the URSA V3 keeps e-liquid inside the cartridge, delivering a smooth, clean e-cigarette experience at all times. If you’re tired of leaky vape cartridges, the URSA Cartridge V3 is the ideal choice.

Share On: