Vol. 1, No. 3, October 1995

Lepel Receives ISO 9001 Certification
A specially assigned team led by Lepel president John Stoll, has successfully guided Lepel Corporation through the ISO 9001 certification process. Lepel's Edgewood, New York facility is now certified under ANSI/ASQC ISO 9001:1994 Quality Standards. This facility is among the first American plants to achieve certification under the more stringent 1994 quality standards - and it is the first induction heating facility to do so.

ISO 9001 is a standard used by companies around the world to establish and maintain continuous improvement in total quality management systems. Certification requires extensive documentation of procedures to ensure product consistency and process

repeatability. Lepel expects the ISO 9001 guidelines and auditing procedures to further improve the quality of its products and services.

According to Vladimir Pilic, Lepel's Vice President of Sales, the ISO 9001 certification will greatly enhance Lepel's appeal both within the United States and abroad. "ISO 9001 is a prestigious label," Pilic commented, "even if a potential customer is not aware of our accomplishments in the industry, they will be attracted to the ISO 9001 certification." Other Lepel employees were equally enthusiastic According to Don Blau, Lepel's lead Sales Engineer, ISO 9001 is an effective way of letting potential clients know what Lepel employees have known all along.

Lepel's Applications Lab Provides the Answers to the Most Important Questions
When a company is considering Induction Heating for their application, the natural questions are:
  • Can it be done?
  • What is the best concept?
  • What equipment will we need?
  • What will it cost?
When a client or prospect asks these questions, Lepel turns to its Applications lab for the answers.

Technicians in the Lepel Applications lab receive samples of the client's part along with the desired process specifications and required production capacity, and use this information to design a customized induction heating process. They create a prototype induction coil and model the process to determine what size and frequency power supply and induction coil is required.

Then, they determine what other equipment is necessary, how the induction heating equipment will need to be integrated, and answer any application-specific questions. The technicians, with Engineering and Sales, will also provide an estimate of the cost of the recommended induction heating system. Metallurgist, Tim Hussey, evaluates the finished product to confirm that the samples comply with desired process specifications and meet any other required parameters.

Unless the sample processing is complicated, requiring a great deal of time and material, lab services are complimentary.

The Lab tries to respond to client inquiries within 4-5 days of receiving samples. To accomplish this rapid turnaround there are over 700 induction heating coils on hand with numerous Lepel Induction generators, optical pyrometers, mounting equipment, hardness testers, temperature monitors and other instrumentation.

For more information on Lepel's Applications Lab, contact Don Blau or Tim Hussey at (516) 586-3300.

Product Spotlight:
Lss Series Power Supplies Offer Superior Performance in a Compact Package
Lepel's LSS line consists of six of the smallest and lightest RF power supplies in the industry. Comparably powered units can be more than five times as large and up to 350 kgs heavier. Yet with this light weight and compact design, the popular LSS series is still able to deliver superior performance.


Made from 100% solid state components, the LSS line provides consistent power, eliminating warm-up and the reduction of output typical of oscillator tubes as they age. A solid state circuit breaker, backed up by fast acting semiconductor type fuses, guards the power devices. Conversion efficiencies up to 85% minimize energy costs and greatly reduce water cooling requirements.

The LSS line also delivers solid state accuracy assuring power regulation of n 0.5% with line variations up to n 10%. Diode rectification provides an input power factor of 0.95 regardless of loading and a rugged DC diode bridge and DC filter minimize the effects of line noise and harmonic feedback to the input line.

With LSS models, reliability is guaranteed through innovative engineering. The cooling water never comes into contact with DC potentials, eliminating both electrolysis and corrosion of the water fittings. An optional computer port enables interfacing with a computer for automated control and record keeping and a built-in digital timer can be used to automatically time the heat cycle and shut the system off.

The LSS line is perfect for a wide range of applications including brazing, annealing, soldering, tempering, hardening, melting, bonding, shrink fitting, coating and epitaxial growth. Every unit provides efficient, trouble-free performance and ease of operation. LSS models are available with output powers from 2.5 kW to 60 kW at frequencies of 50-200 kHz.


New Applications
  • Pre-heat for subsequent coating or rotors
  • Solder coating of braided wirebands
  • Profiled case hardening
  • Varnish coating removed from copper wire bundles
  • Brazing refrigeration tube assemblies
  • Brazing in atmosphere bright joint assemblies
  • Shaft bonding into Delrin
  • Fusing aluminum to copper
New Portable Power Supply Perfect for Trade Show Demonstration

The newest addition to the MR-Series solid-state power supplies is a one kilowatt, air cooled power supply, lightweight enough to carry and use anywhere. The unit is compact for easy handling (16.25" x 17.25" x 10.875") and is designed for use in a wide range of applications including heat treating, soldering, bonding and shrink fitting. 		The popular MR-Series operates with conversion efficiencies of 85% to 90% to minimize energy costs and each unit comes with built in protective devices to prevent circuit overload, excessive temperatures or over frequencies. The MR-Series features a manually adjustable, multi-tapped tank coil to match a wide range of load coils. This patented design requires fewer circuit components than any comparable power supply on the market, making it easier to maintain, adjust and operate.

Dear Don

Don Blau has a Bachelor of Science in Physics and over 20 years of induction experience with Lepel. He is Lead Sales Engineer.

Q: We are preparing to manufacture and assemble small mechanical products in which most of the components are brazed (brass to brass) subassemblies or similar parts that require localized case hardening of steel components. In developing an induction heating system for the required brazing and localized hardening, we are experiencing a high level of inconsistency and thus inferior product quality. We are using a low power, 2.5 kHz Induction Generator with frequencies between 50 and 200kHz, The time cycles to effect most brazes and localized hardening are on the order of several seconds. Could you please comment on our application, particularly focusing on what our problems might be and any corrective measures you would recommend.

A: You mentioned that your induction heating application involves very small parts and that short heat cycles are employed to effect brazes and perform localized hardening. This indicates a wide variety of possible problem areas.

Working from your brief description of the application, I suspect that one or possibly a number of the following conditions are leading to the unacceptable inconsistency of results.

Part Qualification
For small parts or assemblies, part qualification is essential. These pieces need to be consistently located through proper nests and fixturing during the heat cycle interval. If not properly nested or held, the electromagnetic field generated by the load coil, in the case of steel parts, can cause part deflections or movement which will result in non-uniform case and zone of case.

RF Power Variations
Variations in net RF power applied during a heat cycle as a result of variations in rise and fall times can contribute to inconsistency in a process, especially in the case of a short heat cycle where variations in size and fall times, if not controlled, represent a significant percentage of overall cycle time.

Setting Repeatability
If an induction generator is used to process a number of different parts requiring differing power settings and time cycles, it is essential for consistency that settings be repeatable. An induction power supply will need to have a power setting potentiometer, usually a ten turn potentiometer and a high resolution electronic timer resolvable to plus or minus one millisecond.

Quenching Delays
A significant cause of inconsistent case depth and hardness when hardening steel is the manner in which the part is quenched. Delays or variations in applying quench will contribute to inconsistency of product. In cases where quench cells are utilized, it is best that they be charged prior to the termination of the heat cycle and that the part be delivered to the spray quench region in a controlled manner. Drop quenching by immediately releasing the heated part into a submerged quench medium requires that the part release mechanism be accurately controlled and that the part enter the submerged quench in a controlled orientation.

While all of these problems can be solved individually, the only way to ensure consistent part heating is to utilize the latest, highest quality induction heating equipment in your process. One way to do this is to contact Lepel, the industry leader in induction heating, for reliable products and services to meet all of your induction heating requirements.

Send your technical questions to:
DEAR DON
Lepel Corporation
50 Heartland Blvd., Edgewood, NY 11717