Choosing the right explosion-proof cable gland is an important step in protecting electrical equipment installed in hazardous environments.
Choosing the right explosion-proof cable gland is an important step in protecting electrical equipment installed in hazardous environments. The wrong gland may compromise sealing performance, cable retention, or the integrity of the equipment’s explosion protection. For engineers, electrical contractors, and purchasing teams, the selection process should go beyond checking the product size.
This guide explains how to choose an explosion-proof cable gland based on hazardous area classification, cable construction, thread specifications, and operating conditions.
Before selecting a cable gland, determine whether the installation is exposed to flammable gases, vapors, or combustible dust. Different environments require different explosion protection methods and certification levels.
For example, oil and gas facilities, chemical plants, mining operations, and offshore installations may require certified cable entry devices suitable for their specific hazardous areas.
When evaluating a gland, check the following:
Hazardous area classification: Confirm the applicable gas or dust zone and equipment protection level.
Explosion protection method: Verify that the gland is suitable for the protection concept used by the connected enclosure, such as flameproof or increased safety protection.
Certification: Check the required ATEX, IECEx, or other local approvals, including the certificate scope and product markings.
Environmental conditions: Consider moisture, corrosion, temperature, vibration, and exposure to chemicals.
A gland that works in a general industrial environment is not automatically suitable for an explosive atmosphere. The final selection must comply with the applicable installation standards and equipment certification.
Cable construction determines how the gland grips the cable, provides sealing, and handles mechanical loads. Choosing the wrong type can lead to poor sealing or inadequate armour clamping.
| Cable type | Selection considerations |
|---|---|
| Armoured cable | Choose a compatible gland designed to clamp the armour and provide the required sealing. |
| Unarmoured cable | Check the cable's outer diameter, sheath material, and required sealing arrangement. |
| Braided or shielded cable | Confirm compatibility with the braid or shielding structure and any bonding requirements. |
| Special or flexible cable | Verify the gland's clamping range, flexibility requirements, and resistance to movement or vibration. |
For armoured cables, also check whether the installation requires electrical continuity through the armour. For unarmoured cables, the sealing ring must match the cable's actual outside diameter.
In some flameproof applications, a barrier-type gland may be required to prevent gas migration through the cable structure. This decision depends on the cable construction, enclosure protection method, certification, and applicable standards—not simply on whether the cable is armoured.
Two measurements are particularly important when selecting a cable gland: the cable's outside diameter and the enclosure's entry thread.
The cable diameter determines whether the sealing system can grip the cable correctly. The thread specification determines whether the gland can be installed securely in the equipment.
Common thread types include:
Metric threads (M): Common in equipment manufactured for many international markets.
NPT threads: Widely used in North American industrial installations.
G/BSP threads: Found in various industrial piping and electrical equipment applications.
PG threads: Still encountered on some legacy equipment.
These thread systems are not interchangeable simply because their nominal sizes appear similar. Check the thread standard, pitch or profile, and entry dimensions before ordering.
A practical selection checklist includes:
Measure the cable's actual outside diameter.
Confirm the enclosure entry thread and available mounting space.
Check the gland manufacturer's cable clamping range.
Verify the required thread engagement and sealing accessories.
Confirm the selected combination matches the product's certified configuration.
Never rely on an approximate size or use improvised sealing materials to compensate for an incorrectly sized gland.
The operating environment also affects the service life of an explosion-proof cable gland.
Nickel-plated brass is commonly used for general industrial applications, while stainless steel may be preferable in certain corrosive or marine environments. Material selection should consider the enclosure material, surrounding chemicals, humidity, and the risk of galvanic corrosion.
Sealing performance is equally important. Check the required IP rating, ambient temperature range, seal compatibility, and whether the complete assembly—including any washers or adapters—maintains the intended protection.
During installation, follow the manufacturer's instructions for tightening, cable preparation, and inspection. Avoid damaging the cable sheath, deforming the sealing components, or mixing parts from incompatible products.
To reduce selection errors and speed up procurement, prepare the following information before requesting a quotation:
Equipment application and hazardous area classification
Required explosion protection method and certification
Cable type, construction, and outside diameter
Enclosure thread type and size
Required IP rating and operating temperature
Installation environment and material requirements
Estimated quantity and any special design requirements
Providing these details allows suppliers to recommend a suitable explosion-proof cable gland rather than relying on a product name alone.
Founded in 2015, BJBON Technology Co., Ltd. is a technology-oriented company specializing in cable sealing products, conduits and conduit fittings, cable chains, and plug connectors. Guided by a commitment to learning and innovation, BJBON provides cable protection system solutions for new energy vehicles, railway systems, aerospace equipment, robotics, wind power equipment, industrial machinery, construction equipment, electrical installations, lighting, and elevators. With years of experience in cable protection, BJBON has earned recognition from customers and end users in China and international markets. If you are sourcing cable glands or need help matching cable entry products to your application, contact BJBON's team to discuss your requirements and find a suitable cable protection solution.
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