Sealing glands or sealing transits are used to secure instrumentation wire and tubing, providing entry into pressurized, vacuum, or hazardous chambers and environments.
Sealing glands are manufactured from a number of materials, all of which lend different characteristics to the quality of the gland. Aluminum glands are versatile, lightweight, and relatively corrosion-resistant general application material; but they do not offer the specific strength advantages of steel glands. Steel glands are available in general purpose and stainless steel varieties. While both offer superior service strength, stainless steel adds a higher degree of corrosion resistance. Many sealing glands are designed using thermoplastic materials, which provide good sealing properties, but are of limited use in chemical or fire resistant applications.
Sealing glands or sealing transits are used to secure instrumentation wire and tubing, providing entry into pressurized, vacuum, or hazardous chambers and environments.
Sealing glands are manufactured from a number of materials, all of which lend different characteristics to the quality of the gland. Aluminum glands are versatile, lightweight, and relatively corrosion-resistant general application material; but they do not offer the specific strength advantages of steel glands. Steel glands are available in general purpose and stainless steel varieties. While both offer superior service strength, stainless steel adds a higher degree of corrosion resistance. Many sealing glands are designed using thermoplastic materials, which provide good sealing properties, but are of limited use in chemical or fire resistant applications.
When determining which of the available sealing glands is best for the needs of a given application, there are a number of specifications to be aware of. Considerations include how many cables, wires, tubes or electrodes will need to be carried by the sealing gland, and of what diameter are these items that will be fed through the gland. The amount and diameter of the pass through elements will partly determine the size of the gland needed. In some respects though, there may already be a limitation on pass through items based on the size of the hole through the bulkhead through which the sealing glands will be installed. Once the size of the gland and the amount of items, which will be passed through it, are known, the final major specification is to determine the maximum pressure that will be applied to the transit while in use. Most sealing glands have a specific pressure rating to help simplify the process.
Sealing glands may offer a number of additional features and ratings to help the consumer decide which of the available types is best for the application at hand. Some of these features include fire stops (which do not allow flame to pass through the transit), EMI / RFI shielding (to minimize or eliminate radio frequency and electromagnetic interference), whether the sealing gland can accommodate pre-terminated cables (the transit can typically be opened up to allow termination pass through and enable subsequent resealing), and whether it is explosion-proof.
