Refractory Metal Heating Elements and Shields
MRF, LLC supplies resistive heaters and shields designed in-house and fabricated by our refractory department. We pride ourselves for our heating elements and shields with excellent temperature uniformity and longevity. Our range of metallic mesh heaters adds to this excellent uniformity, high temperature ramp-up speeds, high watt densities, and an exceptionally long useful life with minimal performance degradation over time. Our high-quality workmanship, the excellent performance of our zones and our competitive pricing make using MRF made parts an easy choice.
MRF manufactures hot zones with the following metals:
- Tungsten (3000 °C max.)
- Molybdenum (2000 °C max.)
- Tantalum (2300 °C max.)
- Platinum (1600 °C max.)
- Stainless Steel (1000 °C max.)
- Inconel (1000 °C max.)
- Kanthal (1700 °C max.)
- NiCr (1200 °C max.)
- Mesh heaters, Panel Heaters, Rod Heaters
- Round hot zones, Rectangular Hot Zones
- Vacuum, Inert, Oxidizing or Reducing Environments
Graphite Heating Elements and Shields
MRF designs and supplies graphite hot zones, available on the majority of our furnaces. Capable of extremely high temperatures, heating elements are made from a high-purity low-resistance grade of graphite, while heat shields are made of fibrous panels with excellent insulation values to minimize heat loss and provide a uniform temperature gradient.
- heating elements (3000 °C max.)
- fibrous shield packs
- graphite hot rods
- graphite mounting hardware
- graphite bolts, nuts, pins
Ceramic Hot Zones
MRF, LLC supplies Molybdenum disilicide elements and fibrous alumina silicate insulation shields for operation in air up to 1650°C. We also furnish bare wire NiCr or cemented NiCr elements. These hot zones are suited for operation in air or highly oxidizing environments. Muffle tubes or retorts to separate the parts and heaters are also available.
Ceramic Hot zones materials:
- Molybdenum disilicide elements (1650 °C max.)
- Fibrous alumina silicate insulation
- NiCr heaters (1200 °C max.)
- Kanthal heaters (1700 °C max.)
- Inconel heaters (1000 °C max.)
O-rings and Other Vacuum Seals
To maintain optimal vacuum performance, especially around seals that are suspect to wear like door seals, sliding seals or rotating seals, vacuum seals should be kept as spares in the event of vacuum leaks or maintenance. Available seals that we stock are:
- Quad seals
- Spring loaded seals
- 1/8″ ID to 72″ ID
- Variety of Cross sections
Insulators, Ceramic parts, Gaskets..
High temperature furnaces use a variety of insulators to provide an electrical or thermal barrier.
- Ceramic insulators
- Ceramic washers
- Ceramic tubes
- Graphite mounting hardware
- Vacuum, power or wire feed-throughs
Most of these parts can be found on a typical water-cooled high temperature furnace. As many of these parts are fragile and are exposed to extreme conditions, they should be kept on hand as some might need replacement during dis- and re-assembly or during maintenance.
Thermocouples are a popular means for measuring temperature due to their simplicity, relative low cost, and availability of different TC types for different environments and temperature ranges. MRF High Temperature Furnaces typically use Type C sheathed thermocouples for measurements up to 2000°C, beyond that an optical pyrometer is added to supplement the measurement range. Type C TCs have the highest available range and when sheathed they can be employed in vacuum, inert, reducing or oxidizing environments.
TCs will drift over time and become less accurate before failing. Regular calibration or replacement is required to ensure accurate and reliable measurements. For these reasons, a few spare TCs should always be kept on hand. MRF specifically stocks TCs for high temperature furnaces not easily found elsewhere.
- 1/16″, 1/8″or 1/4″ diameter
- 4″ to 24″ length
- Type J, K, S and C
- Matching extension wire and plugs
- Vacuum rated TC feed-throughs
- Tungsten, Molybdenum, Inconel, Stainless steel, Tantalum Sheaths
- Bare wire TCs
Most high temperature furnaces rely on low voltage high current heaters, where 2000 amp conductors are not uncommon. To carry this current from the power supply to the heater in an efficient manner, we supply water cooled power cables, which allow a much smaller conductor to be used versus using air cooled conductors. This allows for larger distances between power supply and furnace with smaller diameter conductors.
If your system is already equipped with water cooled power cables, we can also offer replacements for old cables that have become less efficient due to corrosion or water flow restrictions. We can supply cables of any length and current capacities of up to 4000 Amps for any high temperature furnace. For clean room application, we also supply power cable feed through flanges and other accessories.