Mineral insulated heating elements: one-wire (CVX & CXX) and two-wire (BVX & BXX)

Often our client’s thermal needs call for a customized heating solution from Kamet wherein we design  bespoke heating assemblies in close collaboration with our partners. For example, our  resistive mineral insulated heating elements can be cast in solid metal plates to ensure uniformity in the heating process.

However, Kamet also supplies a range of standard individual mineral insulated resistance heating elements.  These are available as one-wire heating elements (internal reference CVX & CXX heaters) and two-wire heating elements (internal reference BVX & BXX heaters). The flexibility of these heaters means that the client has various mounting options to match their specific application for example, coiling, clamping, brazing or casting. On this page we provide more detailed information on these heaters including their properties and possible applications.

Mineral insulated heating elements

Kamet’s mineral insulated heating elements consist of one (in case of CVX or CXX heaters) or two (in case of BVX or BXX heaters) current-carrying conductors, insulated with magnesium oxide (MGO) and protected with a flexible metal sheath that has a minimum bending radius of 2xOD. The MI heating elements are often supplied with a conductive cold end. This conductive cold end is generally made of material with a much lower resistance value (e.g. copper or nickel). This cold end allows for easy termination.

Internal/seamless hot/cold transitions: means there is no difference in outer (sheath) diameter where hot and cold elements meet. The sheath is electro-etched where internal hot/cold splices are located.

High power density friendly: makes Kamet’s mineral insulated heating elements suitable for applications where the linear power in the heated zone is high (>100 W/m) and the cold ends can go through insulated walls without the concern of overheating.

Physical Properties of CVX, BVX, CXX and BXX

SheathInconel® 600 standard
304SS, 316SS, or 321SS on request
Insulator≥99.4% Compacted MgO
Hot WireInconel® 600 standard
Nichrome 80/20 on request
Cold WireCopper (CVX or BVX)
Nickel (CXX or BXX)
Maximum working temperature
Hot Part1000⁰C
Cold Part300⁰C (CVX, BVX = Copper)
600⁰C (CXX, BXX = Nickel)
Sheath Diameter+0/-0.08mm
Hot Section Linear Resistance±10%
Hot Section Length<1500mm; +0/-10% ≥1500mm; +0/-7%

Heating solids or surfaces

Heating liquidsHeating gases
– Submerge directly in the liquid to be heated
– Maximum power density: <9 W/cm^2 for standing liquid
– Maximum temperature: 980 ⁰C

– Commonly coiled and inserted inside a tube where gas moves over the coils or as oven heating element for harsh environments
– Maximum power density: <4.5 W/cm^2 for standing air
– Maximum temperature: 980 ⁰C
NOTE: For applications with fast moving liquids, power density can be increased. Contact Kamet for advice in this regard.NOTE: For applications with fast moving gases, power density can be increased. Contact Kamet Trading to consult.

Heating in vacuum environments

Radiant heat is one of the most common methods of heat transfer in a vacuum. Electric heaters need to be over 500°C before metal surfaces start to radiate heat away from the surface of the heater. Keeping that heat in the area of the process and away from the cold section of cable brings a new generation of efficiency to radiant vacuum process heating. The desired heating rate and required power will determine the mounting method. Vacuum applications bring particular challenges:

  • A vacuum acts like a heat trap. Until radiant temperatures are achieved the heat stays in the heater or the parts that are being heated.
  • Sensing temperatures from metal heater surfaces in a vacuum can also be difficult.

Contact us for more advice on this matter.

NOTE: For increased life time or heating uniformity, brazing or casting is recommended even if < 4.5 W/cm^2

Mounting methods

Heating elements can be mounted onto all kinds of materials. Due to its flexibility, the heaters can be bent in several shapes to transfer heat effectively. The mounting can be done by wrapping the heating element around the object to be heated, but it can also be grooved or brazed onto a surface. The chosen mounting method depends on the desired heating rate and required power. The table below contains information on the parameters of various mounting methods for the mineral insulated heating elements.

Power Density W/cm^2Temperature ⁰CMounting Method
< 3< 980Simple wrap & loose clamping is acceptable
3 – 6< 300Simple wrap & loose clamping is acceptable
3 – 6300 – 600Must be clamped tightly to the object
3 – 6600 – 980Must be partially brazed or cast into the piece to be heated
6 – 15< 980Must be completely soldered, brazed, or cast into the piece to be heated

Kamet’s range of mineral insulated heating elements

  • CVX heaters: One-wire mineral insulated heaters with hot wire of INC600 or Nichrome 80/20 and a copper cold wire
  • CXX heaters: One-wire mineral insulated heaters with a hot wire of INC600 or Nichrome 80/20 and a nickel cold wire
  • BVX heaters: Two-wire mineral insulated heaters with a hot wire of INC600 or Nichrome 80/20 and a copper cold wire
  • BXX heaters: Two-wire mineral insulated heaters with hot wire INC600 or Nichrome 80/20 and a nickel cold wire

Detailed application guide for CVX/CXX

Detailed application guide for BXX/BVX

Our manufacturer: ARi Industries

Our American partner, ARi industries, was established in 1952 and was among the first companies to ever manufacture mineral insulated (MI) cable. In 1980 ARi Industries became a member of the renowned Okazaki group. Okazaki is Kamet’s long-standing partner for the European MI cable market. As such, a working relationship between ARi Industries and Kamet Trading was established.

A very important aspect of Kamet’s partnership with ARi Industries, is the active collaboration on custom-made heaters for our clients. This benefits our clients in a number of ways:

  • Customers’ specific heating needs are fulfilled with heating elements in an overall design that is perfectly customized for their unique environment and process.
  • As experts on their own products, ARi Industries ensures the best performance from each heater and for the heating setup as a whole.
  • ARi Industries are leading-edge heating experts and, as such, our clients are ensured the very latest technological advances are brought to their thermal challenges.
  • Through our partnership, Kamet has access to a wide range of customizable heating cable and elements. Furthermore, if we need to make use of ARi Industries in-house capabilities to tailor make an element, they offer the capacity to ensure a quick turnaround and delivery time.

Why do business with Kamet?

Not only do we offer these extensive testing options in partnership with ARi, but we also offer services through other partner companies such as vacuum brazing whereby the heater is cast into the customer’s required material.

Not only do we bring a range of services in partnership with ARi, but our customers also benefit from the extensive experience and know-how of our own team. We are on hand to answer all your queries and we can be relied on to respond within 24 hours. Although we are leading technical experts in this field, our team prides themselves on being approachable and ‘easy to do business with’. We look forward to hearing from you. Please feel free to contact us with your particular heating needs.

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