Water dispensers come into direct contact with our daily drinking water, making safety the top priority. The heating element—the core component responsible for heating—directly determines the water dispenser's heating efficiency, service life, and most critically: electrical safety.
A qualified water dispenser heating element must be able to operate while fully immersed in water for long periods without leakage, rusting, or scaling. What determines whether it can achieve this? Besides the material itself, there is one easily overlooked yet essential process: end sealing treatment.
Water dispenser tubes are water-immersed heating elements, meaning they operate while completely submerged. This requires them to withstand not only the thermal shock of repeated heating and cooling cycles, but also the risks of corrosion and scaling caused by impurities and minerals in the water.
If a heating element is poorly sealed, moisture can penetrate through the microscopic gaps at the tube ends, leading to:
Therefore, the core requirements for water dispenser tubes are: no leakage under long-term immersion, and stable heating performance without degradation.
As shown in the process flow diagram, after the terminal tabs are spot-welded, microscopic gaps remain at the tube ends. If sealing treatment is skipped or improperly executed, moisture will "enter through these gaps."
The purpose of end sealing is threefold:
The magnesium oxide powder inside the heating element offers excellent thermal conductivity but is hygroscopic. The sealing layer acts as a "watertight barrier," preventing moisture from entering and ensuring insulation resistance remains compliant.
Spot-welded terminal tabs may experience micro-movement due to thermal expansion and contraction during use. Sealing material helps secure them, preventing poor contact.
Sealing also prevents impurities and minerals in the water from entering tube end gaps, delaying corrosion and prolonging the heating element's service life.
As a professional heating element manufacturer with 30 years of experience, Shenzhen Angel Electric Heater Co.,Ltd. designates the sealing process as a Key Control Point and has developed distinct technical advantages:
✅ Material Optimization for Reliable Sealing
Based on application requirements, we select appropriate sealing materials—such as silicone, epoxy resin, etc.—ensuring high-temperature resistance and anti-aging performance.
✅ Controlled Process for Thorough Protection
We strictly control sealing quality to ensure sealing materials fully fill the tube ends, creating a complete, closed protective layer.
✅ 100% Inspection for Guaranteed Quality
Every water dispenser tube undergoes Insulation Resistance Testing and Hi-Pot Testing after sealing curing, ensuring full electrical performance under immersed conditions. We also conduct regular damp heat tests and lifespan tests to simulate long-term use and verify sealing durability.
✅ Multiple Material Options for Various Water Qualities
Addressing water quality differences across regions, we offer various sheath materials including SUS304, SUS316L, and Incoloy. Combined with rigorous sealing processes, we meet customer requirements for corrosion resistance and anti-scaling performance.
Choose Angel—Every Drop Heated Safely
Though small, the water dispenser heating element affects the drinking water safety of countless households. At Shenzhen Angel Electric Heater Co.,Ltd., we never overlook any detail—from material selection to sealing treatment, from automated production to multiple inspections—all to ensure every heating element leaving our factory achieves: no leakage under immersion, lasting peace of mind.
If you are looking for a reliable heating element supplier, welcome to contact us. Let our 30 years of professional expertise safeguard your products.
