FREQUENTLY ASKED QUESTIONS
Here are some frequently asked questions we receive from clients about Hermetic Seals.
Can RHSeals seal customer supplied wire, cable, or fiber optics?
RHSeals can seal almost any individual or combination of wire, cable, connector, fiber optics, etc. at any length. Please contact our sales department to discuss your particular material and application. If there are any concerns about our ability to seal to your material, we will try a sample for free.
What are the benefits of a fiber optic feedthrough?
Fiber optic feedthroughs allow for more data transfer, while weighing less than copper. Additionally, they do not conduct electricity, so they are safe for use in engines and other similar environments.
Can RHSeals hermetically seal stranded wire?
RHSeals can seal stranded wire as well as it seals solid conductor or solid pins. Most RHSeals hermetic seals will pass a helium leak rate of 1X10-8 std-cc/sec or better, and pressure tests up to 11,000 psi (758 bar). Please see the drawing for the individual part number you are interested in to verify the test specifications and operating limits.
How are your wire feedthroughs tested?
As a service to the customers, every seal produced is electrically tested with a computer controlled hi-pot machine and leak tested using either a helium mass spectrometer or a high-pressure bubble test before shipment. Certification of tests is included with each shipment.
Can RHSeals hermetically seal customer supplied connectors?
We have yet to find a connector that we cannot hermetically seal! If you have specific questions or concerns regarding a connector, please contact our sales team.
Are there different housing options for your connectors?
Yes! We offer housing options including aluminum, steel, stainless steel, epoxy, plastics, titanium, brass, nickel, etc.
What is a hermetic seal?
Hermetic seals allow for currents or signals to be transferred between two separate, sealed environments. These transfers are made without interruptions from moisture or gases leaking. If moisture or gases leak, condensation can wreak havoc on one or both of the environments. By using hermetic seals, the risk for damages is minimized.
What is outgassing?
Outgassing (also known as offgassing) is the release of gases that were trapped inside a material. For example, plastics and rubbers trap gases, and when they are heated or placed in a vacuum, the trapped gases are released. This becomes an issue when the gases contaminate the surrounding environment and negatively affect the readings or performance.
Are RHSeals products RoHS compliant?
All RHSeals products are RoHS compliant unless specified on the assembly print.
Does RHSeals provide ceramic or glass-to-metal seals?
No, RHSeals does not currently offer ceramic or glass-to-metal seals.
Does RHSeals use low outgas materials?
Yes, whenever possible, RHSeals uses low outgassing materials. Our epoxy is low outgas and approved by many national labs for many applications, including aerospace applications and space flight.
Why does RHSeals charge nonrecurring engineering charges (NRE)? Nonrecurring engineering charges (NRE) are fees charged by manufacturers or service providers for the design, development, and testing of a new product or service. The purpose of these charges is to cover the one-time costs associated with the development of a custom or specialized product or service that is not part of the provider’s standard offerings.

NRE charges typically include costs related to research, development, design, prototyping, testing, and tooling, among others. These charges are incurred only once for each custom product or service and are not part of the ongoing costs associated with manufacturing or delivering the product or service.

For example, a manufacturer may charge NRE fees to a customer who wants to order a customized version of a product with unique features or specifications. The NRE charges cover the costs associated with designing and developing the customized product.

Overall, the purpose of NRE charges is to compensate the manufacturer or service provider for the time, resources, and expertise required to develop a unique, customized product or service for a customer.

RHSeals does not charge a NRE again on the same part number unless the customer requests changes requires tooling changes.

How do I install my RHSeals product?
Below are general instructions, please see the housing print for detailed views of possible installations ports and instructions. If for any reason you experience difficulty please contact RHSeals for help.
  • Pipe Thread Housings: Thread tape or thread sealant must be used on the threads unless the print specifies differently. If using tape, the tape should be wrapped clock-wise if looking at the thread end of the housing.
  • Face Seal Housings: RHSeals face seal assemblies are tested and shipped from the factory pre-lubed with the lubricant specified on the print unless no lube is specified. Very little force is required to make a good seal, and in most cases hand tight will do. Just tighten until the housing is seated to your bulkhead.
  • Gland Seal Epoxy Housing: RHSeals gland seal assemblies are tested and shipped from the factory pre-lubed with the lubricant specified on the print unless no lube is specified. There are many different ways to install RHSeals gland seal assemblies, please see the specific housing print for detailed installation port dimensions and instructions.
  • FL/KF Flange Housings: This style housing requires like flange and clamp for proper mating. Contact the RHSeals sales team for help selecting the proper flanges and clamps.
  • Custom Housing: Please see print or contact RHSeals for support.