Wax Thermostatic Element LG0304
The LG0304 Wax Thermostatic Element is a progressive-stroke thermostatic actuator engineered for applications requiring increasing mechanical response as temperature rises through the 35°C to 55°C primary activation range. Built with Legom’s proprietary patented wax formula, it delivers consistent, repeatable stroke actuation across a rated lifespan of 100,000 cycles. It has passed European product certification by accredited institutions including ACS and WRAS.
Unlike elements that deliver their largest stroke in the lower portion of the active range, the LG0304 is engineered to accelerate: its stroke increases from 1.25mm in the 35°C~45°C band to 2.1mm in the 45°C~55°C band. Combined with a maximum temperature rating of 100°C and a total stroke of up to 6.5mm across the full 35°C to 100°C span — among the highest total stroke in the Legom wax element range — the LG0304 is suited for valve assemblies requiring progressive, high-travel actuation across a broad temperature range.
Key Benefits
- Progressive stroke profile – Stroke increases from 1.25mm at 35°C~45°C to 2.1mm at 45°C~55°C, delivering greater piston travel as temperature rises rather than tapering, matching the thermal demand curve of many heating and mixing applications
- Highest total stroke in the Legom range – Total stroke ceiling of 6.5mm across 35°C to 100°C is the largest cumulative stroke output among Legom wax elements, providing maximum valve travel for assemblies that require full-range proportional control
- Maximum temperature rating of 100°C – Alongside the LG001X and LG005X, the LG0304 is rated to 100°C maximum, making it suitable for solar thermal, high-temperature HVAC, and industrial applications where fluid temperatures can reach near-boiling
- High testing load of 70N – Among the higher testing loads in the standard-force Legom range, providing strong actuation force at the 35°C reference point
- Patented wax formula – Proprietary Legom formulation delivers superior sensitivity and temperature-response accuracy versus standard wax elements
- ACS and WRAS certified – Passed European experimental institution product certification, confirming suitability for potable water and HVAC applications in international markets
- Rated for 100,000 cycles – Exceptional service life verified through rigorous lifecycle testing, ensuring reliable long-term performance in high-use installations
- Copper construction – Corrosion-resistant material ensures long-term durability in wet and thermally cycled environments
- OEM and ODM customization available – Temperature range, working stroke, and maximum load can be customized to suit specific product requirements
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | LG0304 |
| Material | Copper |
| Maximum Load | 140N |
| Minimum Load | 60N |
| Testing Load | 70N |
| Spring Rate | 5N/mm |
| Maximum Temperature | 100°C |
| Stroke | L = 19.7 ± 0.3mm at 35°C, 70N |
| Lifespan | 100,000 cycles |
| Certification | ACS, WRAS |
Temperature vs. Stroke
| Temperature (°C) | Stroke (mm) |
|---|---|
| 35°C ~ 45°C | 1.25 ± 0.15 |
| 45°C ~ 55°C | 2.1 ± 0.2 |
| 35°C ~ 100°C | 6.5 (Max) |
Stroke values measured during heating-up cycle. Cooling-down cycle may exhibit slight hysteresis typical of wax thermostatic elements. Refer to the Temperature VS. Stroke curve in the Datasheet for the full graphical representation.
Application & Use Cases
- Thermostatic mixing valves (TMV) – The progressive stroke profile makes the LG0304 suited for TMV assemblies where greater valve opening is required as temperature rises toward the anti-scald threshold, rather than tapering off
- Solar thermal systems – The 100°C maximum temperature rating accommodates the high fluid temperatures in solar collector circuits, while the 35°C activation start covers system warm-up from near-ambient conditions
- High-temperature HVAC and industrial heating – Applied in thermostatic control assemblies for heating circuits where fluid temperatures span from comfort range through elevated industrial operating temperatures
- Automotive engine cooling systems – Applied in engine thermostats requiring progressive actuation from warm-up temperatures through full engine operating temperature, with increasing valve opening as the engine heats up
- Domestic and commercial hot water systems – Used in thermostatic control devices where the valve must open progressively and continue traveling as hot water delivery temperature rises
- Plumbing, sanitary, shipping, military, and other industries – Suitable for any application requiring self-acting, progressive thermostatic control with high total stroke across a broad and elevated temperature range
Installation Notes
- The LG0304 must be installed in direct contact with the fluid whose temperature it is intended to sense, ensuring accurate progressive response across the full 35°C to 100°C operating range
- Ensure the element is fully immersed in the flow path within the host valve or assembly. Partial immersion will reduce the effective stroke output and distort the progressive response profile
- Do not expose the element to temperatures exceeding 100°C, as this is the maximum rated temperature. Sustained exposure beyond this limit may permanently degrade the wax charge
- Avoid applying forces exceeding the maximum load of 140N to the piston during assembly or operation
- The host valve mechanism must be designed to accommodate the full 6.5mm total stroke to allow complete valve travel across the rated temperature range without mechanical obstruction
- The host valve or actuator assembly must provide adequate spring-back force to reset the piston on cooling, as the wax element generates push force only during heating
- Keep the element away from external heat sources not part of the intended sensing medium to avoid premature actuation
- For OEM integration, confirm three key parameters in writing before finalizing the order: temperature range, working stroke, and maximum load
Frequently Asked Questions
What makes the LG0304 distinctive compared to other Legom wax thermostatic elements?
The LG0304 has two standout characteristics in the Legom range. First, its stroke profile is progressive — the stroke in the second band (45°C~55°C, 2.1mm) is larger than in the first band (35°C~45°C, 1.25mm), meaning the element delivers more piston travel as temperature rises rather than tapering off. Most other multi-stage models in the Legom range either taper or include deceleration zones above the primary band. Second, its total stroke ceiling of 6.5mm across 35°C to 100°C is the highest among Legom wax elements, providing the greatest cumulative valve travel for assemblies that need full-range proportional control.
How should I read the three-row stroke table?
The first row (35°C~45°C, 1.25mm) gives the initial actuation band. The second row (45°C~55°C, 2.1mm) shows that more stroke is delivered in the second 10°C band than in the first — confirming the progressive profile. The third row (35°C~100°C, 6.5mm max) gives the total stroke ceiling across the full operating span. Refer to the Temperature VS. Stroke curve in the Datasheet for the complete graphical representation of both heating-up and cooling-down cycles.
What certifications does the LG0304 hold?
The LG0304 has passed European experimental institution product certification under ACS and WRAS standards, confirming its suitability for use in drinking water systems and broader HVAC and plumbing applications in certified markets.
What is the expected service life of the LG0304?
The LG0304 is rated for 100,000 actuation cycles, supporting long-term deployment in high-use installations across its full 35°C to 100°C operating range.
Can the LG0304 be customized for different temperature or stroke requirements?
Yes. Legom offers full OEM and ODM customization. If your application requires a different activation temperature, working stroke, or load specification, the engineering team can develop a customized solution. Written confirmation of three key parameters is required before any customization project begins: temperature range, working stroke, and maximum load.
How do I select the right wax thermostatic element for my product?
The key selection criteria are the required activation temperature range, the working stroke needed to actuate your valve mechanism, and the maximum load the element must deliver. If you are unsure about any of these parameters, the Legom team can assist with selection or develop a custom element. Contact us via WhatsApp or email to begin the process.
OEM & ODM Customization
Legom supports full OEM and ODM services for the LG0304 Wax Thermostatic Element. Our engineering team can customize the activation temperature range, working stroke, and maximum load to match your product requirements. Before any commitment, written confirmation of three key performance parameters is required: temperature range, working stroke, and maximum load. All customization projects are handled with strict confidentiality. Contact us via WhatsApp or info@legomsmart.com.
Datasheet
Product information last reviewed by the Legom Technical Team. For the most current specifications, refer to the official datasheet or contact our sales team.
Custom OEM & ODM Solutions
Legom is a direct manufacturer offering end-to-end OEM and ODM services. With our in-house engineering and production capabilities, we work closely with distributors and system integrators to deliver fully customized solutions under strict NDA.
