Hongtai Immersion Cartridge Heaters are specialized thermal components designed for direct installation into tank walls, piping systems, and mold temperature controllers. Unlike standard air heaters, these units feature a robust threaded cartridge heater design with a hermetically sealed flange connection, ensuring zero leakage even under high pressure.

Engineered for the rigorous demands of industrial fluid heating, we utilize advanced TIG welding technology to secure the fitting to the sheath. This construction makes them the ideal choice for hydraulic oil tanks, aqueous cleaning systems, and food-grade water heating applications where reliability is paramount.

Key Technical Features:

• Leak-Proof Design: High-integrity TIG welding allows for operating pressures up to 10 Bar (145 PSI).

• Fittings: Standard Brass or Stainless Steel NPT threads (1/2″, 3/4″, 1″) or BSP standards.

• Sheath Materials: Stainless Steel 304 (Standard) or 316L (Food/Corrosive Grade).

• Safety: Customizable Cold Zone (Unheated Length) to prevent overheating at the fitting or due to liquid level fluctuations.

• Efficiency: Direct immersion provides nearly 100% thermal efficiency.

1.Technical Specifications & Fitting Dimensions

The following specifications cover our standard production capabilities for liquid immersion applications. We can customize thread sizes and watt densities based on the specific fluid viscosity (Water vs. Oil).

2.Industrial Applications

This water heating element with flange design is widely utilized in:

1. Mold Temperature Controllers: Precise heating of circulating water or oil for injection molding.

2. Industrial Washing Equipment: Heating cleaning solvents and detergents in ultrasonic tanks.

3. Hydraulic Systems: Maintaining oil viscosity in cold environments (Requires low watt density).

4. Food & Beverage: Sterilization and hot water generation using SS316L materials.

3.Why TIG Welding Matters (Leak Proofing)

In liquid applications, the connection between the heater sheath and the threaded hex fitting is the most critical failure point.

• Standard Method: Many manufacturers use epoxy or simple brazing, which can fail under thermal cycling or high pressure.

• Hongtai Method: We employ TIG (Tungsten Inert Gas) Welding. This creates a metallurgical bond between the fitting and the sheath, capable of withstanding pressures up to 10 Bar. This ensures no fluid leaks into the machine or onto the floor.

4.The Importance of “Cold Zones”

For immersion heaters, the “Cold Zone” (Unheated Section) is a critical safety feature:

• Fitting Protection: We ensure the top 20-50mm of the heater inside the thread is unheated. This prevents heat from transferring directly to the hex nut and the electrical terminals, protecting the wire insulation.

• Liquid Level Safety: For tanks where fluid levels may fluctuate, a longer cold zone ensures the heated portion remains fully submerged, preventing dry-firing and element rupture.

5.Material Selection: 304 vs. 316L

• SS304: Suitable for freshwater, standard oil heating, and general non-corrosive liquids.

• SS316L: Contains Molybdenum for superior corrosion resistance. Mandatory for chlorinated water, mild acids, and food-grade applications to prevent pitting corrosion.

6.SECTION 5: FAQ

Q: Can I use a water heater to heat oil?

A: No. Water heaters have a high watt density (approx 8-10 W/cm²). If placed in oil, the heat cannot dissipate fast enough, causing the oil to carbonize (coke) on the sheath and eventually burning out the heater. You must order a specific Immersion cartridge heater designed for oil (Low watt density: 2-3 W/cm²).

Q: How do I seal the NPT thread?

A: NPT (National Pipe Taper) threads create a seal by interference fit. We recommend using PTFE tape (Teflon tape) or a high-temperature liquid thread sealant during installation to ensure a completely watertight seal.

Q: What is the max pressure this heater can withstand?

A: Our standard TIG-welded units are rated for 10 Bar (approx 145 PSI). For higher pressure requirements, please contact our engineering team for heavy-wall sheath designs.

Need Engineering Assistance?

• Read our comprehensive [Ultimate Guide Cartridge Heaters 2026] to understand safety limits.

• Or, verify your specs directly with our engineering team: [Contact Us for a Quote].