Wax Thermostatic Element LGX075
The LGX075 Wax Thermostatic Element is a high-temperature, high-force thermostatic actuator engineered specifically for boiler systems and high-temperature HVAC applications. With a starting response temperature of 80°C and an active stroke range of 90°C to 99°C, the LGX075 is designed to operate in the upper thermal range where standard wax elements cannot function reliably. Built with Legom’s proprietary patented wax formula, it delivers consistent, repeatable stroke actuation across a rated lifespan of 100,000 cycles.
The LGX075 stands apart from all other Legom wax elements in two critical specifications: a maximum load of 200N — the highest in the Legom range — and a starting response temperature of 80°C, the highest activation threshold available. Its elongated rod-style body, approximately 130mm in total length, is designed for immersion-type installations in boiler and high-temperature HVAC assemblies where the element must reach deep into a fluid chamber to sense temperature accurately at near-boiling conditions.
Key Benefits
- Highest activation temperature in the Legom range – Starting response temperature of 80°C and active stroke window of 90°C to 99°C make the LGX075 the only Legom wax element designed specifically for near-boiling temperature environments
- Highest maximum load in the Legom range – Maximum load of 200N exceeds all other Legom models (next highest is 180N for LG013X and LG008X), providing the force needed to actuate heavy-duty boiler safety and control valves with stiffer return springs
- High testing load of 90N – Confirmed actuation force at the 90N testing condition within the 90°C to 99°C active window, providing a reliable baseline for valve mechanism design
- Rod-style elongated body for immersion installation – Total body length of approximately 130mm enables deep insertion into boiler chambers and high-temperature fluid bodies for accurate temperature sensing at the intended activation zone
- 6mm stroke in a narrow 9°C window – Delivers 6 ± 0.5mm of stroke entirely within the 90°C to 99°C band, providing decisive and concentrated actuation in the critical near-boiling zone
- Patented wax formula – Proprietary Legom formulation delivers reliable actuation sensitivity and repeatability at temperatures that standard wax formulas cannot sustain
- Rated for 100,000 cycles – Exceptional service life verified through rigorous lifecycle testing at high-temperature operating conditions
- OEM and ODM customization available – Temperature range, working stroke, and maximum load can be customized for specific boiler and high-temperature HVAC requirements
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | LGX075 |
| Material | Copper |
| Maximum Load | 200N |
| Minimum Load | 70N |
| Testing Load | 90N |
| Starting Response Temperature | 80°C |
| Max Working Temperature | 99°C |
| Stroke | L = 6 ± 0.5mm between 90°C and 99°C at 90N |
| Lifespan | 100,000 cycles |
The LGX075 activates from 80°C with stroke building progressively through 90°C to 99°C. The specified 6 ± 0.5mm stroke is measured within the 90°C to 99°C window at 90N testing load. Refer to the Temperature VS. Stroke curve in the Datasheet for the full graphical representation.
Application & Use Cases
- Boiler safety and temperature control valves – The primary application listed in the datasheet. The LGX075 is designed for immersion in boiler water circuits where it must actuate reliably at near-boiling temperatures to trigger safety relief, mixing, or diverting valve mechanisms
- High-temperature HVAC systems – Applied in thermostatic control assemblies for medium and high-temperature hot water heating circuits connected to boilers, district heating networks, or industrial heat exchangers where fluid temperatures regularly exceed 80°C
- Boiler overheat protection devices – Used as the sensing and actuation element in boiler high-limit thermostats and temperature-operated safety valves that must respond at defined near-boiling thresholds
- Industrial process heating control – Integrated into thermostatic valve assemblies for industrial heating circuits where process fluids operate in the 80°C to 99°C range and require reliable temperature-responsive actuation with high force output
- District heating system connections – Applied at high-temperature circuit control points in district heating substations where primary circuit temperatures are in the 80°C to 99°C range
- Other high-temperature industries – Suitable for any application requiring self-acting, high-force thermostatic control in near-boiling fluid environments without electrical dependency
Installation Notes
- The LGX075 must be installed with its elongated body fully immersed in the fluid whose temperature it is intended to sense. Given the rod-style body length of approximately 130mm, ensure the installation pocket or well is of sufficient depth to accommodate full immersion
- The element begins responding at 80°C and delivers its specified stroke between 90°C and 99°C. Ensure the installation position exposes the full sensing length to the fluid at these temperatures
- Do not expose the element to temperatures exceeding 99°C, the maximum working temperature. Sustained exposure above this limit may permanently degrade the high-temperature wax charge
- The LGX075 has a maximum load of 200N. Verify that the host valve mechanism does not impose forces beyond this limit during full stroke operation
- The host valve or actuator assembly must provide adequate spring-back force to reset the piston on cooling. With a minimum load of 70N, the return spring must provide at least this force to ensure full piston reset
- For boiler safety applications, ensure the installation complies with applicable national and local boiler safety regulations and that the element’s activation threshold aligns with the required safety setpoint
- 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 LGX075 fundamentally different from all other Legom wax thermostatic elements?
The LGX075 has two specifications that are the highest in the entire Legom wax element range: a maximum load of 200N (all other models are 90N or 140N) and a starting response temperature of 80°C (all other models respond from -5°C to 54°C). These characteristics make it the only Legom element specifically designed for boiler and near-boiling applications. Its rod-style elongated body is also distinct from the compact piston-type bodies of all other Legom models, reflecting its design for deep immersion in high-temperature boiler and process fluid chambers.
Why does the element start responding at 80°C but the stroke is specified for 90°C to 99°C?
The starting response temperature of 80°C marks the point where the wax begins to expand and the piston first starts to move. However, significant working stroke — sufficient to actuate the host valve mechanism — builds up progressively as temperature rises further. The 6 ± 0.5mm stroke specification is measured within the 90°C to 99°C window at the 90N testing load, representing the useful actuation range. This is consistent with how most wax elements exhibit a gradual onset before reaching their specified working stroke.
Is the LGX075 suitable for boiler safety valve applications?
The LGX075 is designed for boiler systems and activates in the 80°C to 99°C range, which aligns with typical boiler operating temperatures. For safety valve applications, confirm with the Legom team that the element’s specific stroke and force characteristics match the valve’s actuation requirements, and ensure the installation complies with all applicable boiler safety standards and regulations.
What is the expected service life of the LGX075?
The LGX075 is rated for 100,000 actuation cycles, supporting long-term deployment in boiler and high-temperature HVAC installations where the element cycles repeatedly through the 80°C to 99°C active range.
Can the LGX075 be customized for different high-temperature activation points?
Yes. Legom offers full OEM and ODM customization. If your boiler or high-temperature HVAC 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: temperature range, working stroke, and maximum load.
How do I select between the LGX075 and other high-temperature Legom models?
The LGX075 is the only Legom model designed for near-boiling temperatures above 80°C. Other high-temperature models such as the LG001X, LG005X, and LG0304 are rated to 100°C maximum but activate from ambient temperature (1°C to 35°C), making them general-purpose wide-range elements. The LGX075 is specifically a high-temperature-only element — it does not respond meaningfully below 80°C — and is the correct choice when the thermostatic assembly must remain inactive at normal ambient and hot water temperatures and only activate near boiling point.
OEM & ODM Customization
Legom supports full OEM and ODM services for the LGX075 Wax Thermostatic Element. Our engineering team can customize the activation temperature range, working stroke, and maximum load for specific boiler and high-temperature HVAC applications. 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.
