Featured Industrial Connection Products
Explore high-performance IP68 and explosion-proof rated cable glands and specialized fittings engineered for critical global infrastructures.
Technical Whitepaper: The Global Engineering Landscape of Double Compression Glands
Deciphering mechanical retention, gas tightness, and ingress barrier dynamics under IEC/EN 60079-0/1/7 and BS 6121 standards.
Dual Independent Sealing
Unlike single compression variants that secure solely on the outer jacket, double compression glands seal concurrently against the cable inner sheath and the external protective jacket. The inner elastomer seal guarantees explosion containment (flamepath exclusion), while the outer seal yields permanent IP66/IP67/IP68 environmental ingress resistance.
Armour Clamping Architecture
Precision mechanical cones and reversible clamping rings mechanically grip Steel Wire Armour (SWA), Steel Tape Armour (STA), or braided aluminium armours. This achieves full pull-out load dissipation compliant with BS 6121 Class 1, protecting internal electrical conductors from tension stress and establishing certified earth fault conductivity.
Hazardous Zone Compliance
Certified for integration within Zone 1, Zone 2, Zone 21, and Zone 22 hazardous zones. Our designs satisfy Ex d (Flameproof), Ex e (Increased Safety), Ex nR (Restricted Breathing), and Ex tb (Dust Ignition Protection) mandates, maintaining boundary integrity even under critical hydrocarbon combustion pressures.
Standard Double Compression Cable Gland Size Chart
Comprehensive dimensional references for Metric (ISO 965-1) and NPT (ANSI/ASME B1.20.1) entry threads, inner/outer sheath clamping boundaries, and armor wire thresholds.
| Gland Size Reference | Metric Entry Thread (D1) | Alternative NPT Thread | Inner Sheath Range Min/Max (mm) | Armour Wire Acceptance (mm) | Outer Sheath Range Min/Max (mm) | Across Flats Hex (mm) |
|---|---|---|---|---|---|---|
| DC-20S | M20 × 1.5 | 1/2" NPT | 3.2 – 8.0 | 0.20 – 0.90 | 6.1 – 13.2 | 24.0 / 26.5 |
| DC-20 | M20 × 1.5 | 1/2" NPT | 6.5 – 14.0 | 0.90 – 1.25 | 12.5 – 20.5 | 30.0 / 33.0 |
| DC-25 | M25 × 1.5 | 3/4" NPT | 11.1 – 20.0 | 1.25 – 1.60 | 16.9 – 27.1 | 36.0 / 39.5 |
| DC-32 | M32 × 1.5 | 1" NPT | 17.0 – 26.3 | 1.60 – 2.00 | 22.0 – 33.5 | 46.0 / 50.5 |
| DC-40 | M40 × 1.5 | 1-1/4" NPT | 22.0 – 32.2 | 1.60 – 2.00 | 28.0 – 41.0 | 55.0 / 60.5 |
| DC-50S | M50 × 1.5 | 1-1/2" NPT | 29.5 – 38.2 | 2.00 – 2.50 | 35.5 – 48.0 | 65.0 / 71.0 |
| DC-50 | M50 × 1.5 | 2" NPT | 35.6 – 44.1 | 2.00 – 2.50 | 42.0 – 53.0 | 70.0 / 77.0 |
| DC-63S | M63 × 1.5 | 2" NPT | 40.1 – 50.0 | 2.50 | 47.0 – 60.0 | 80.0 / 88.0 |
| DC-63 | M63 × 1.5 | 2-1/2" NPT | 47.2 – 56.0 | 2.50 | 53.8 – 65.5 | 85.0 / 93.5 |
| DC-75S | M75 × 1.5 | 2-1/2" NPT | 52.8 – 62.0 | 2.50 | 60.5 – 72.0 | 95.0 / 104.5 |
| DC-75 | M75 × 1.5 | 3" NPT | 59.1 – 68.0 | 2.50 | 66.5 – 78.0 | 100.0 / 110.0 |
Need Non-Standard Thread Pitch or Extended Thread Lengths?
Our Yueqing factory houses dedicated 5-axis CNC machining centers capable of turning PG, BSPP/G, and customized thread engagements for heavy thick-walled offshore bulkhead enclosures.
The Chinese Manufacturing Advantage: Yueqing Industrial Cluster Efficiency
Combining localized metallurgical raw material supply chains, automated Swiss-type sliding head turning, and rigorous quality verification protocols.
Vertical Supply Chain Integration
Situated in Liushi Town, Yueqing—widely recognized as China's electrical capital—HOONSUN benefits from instant, localized access to high-purity CuZn39Pb3 brass ingots, 304/316L stainless bars, and certified chloroprene / silicone elastomers. This eliminates logistics bottlenecks and shortens delivery cycles from months to under 15 business days.
Automated Multi-Spindle Turning
Our workshop deploys modern multi-spindle automatic lathes alongside dual-turret CNC centers. Continuous production ensures micron-level thread precision (class 6g/6H on Metric threads), eliminating cross-threading risks during hazardous on-site installations and delivering reliable mechanical grip across thousands of units.
Continuous Quality Verification
Every single batch undergoes dimensional verification with calibrated go/no-go plug gauges, hydrostatic pressure chamber testing up to 20 bar (exceeding standard IP68 requirements), and salt spray corrosion profiling over 1000 hours for our nickel-plated brass and 316L marine gland options.
Mission-Critical Application Scenarios & Global Procurement Requirements
Understanding the severe environmental factors driving procurement decisions across engineering, procurement, and construction (EPC) conglomerates.
Offshore Oil & Gas Platforms
Exposed to dense saline fog, hydrogen sulfide gases, and extreme weather. Procurement mandates SS316L or marine-grade brass with certified dual displacement seals to prevent vapor migration through inner cable sheathing into pressurized junction control rooms.
Chemical & Petrochemical
Volatile hydrocarbons demand Ex d flameproof boundaries. Procurement engineers verify strict adherence to certified operating temperatures ranging from -60°C to +130°C using specialized fluorocarbon or low-smoke zero-halogen (LSOH) sealing rings.
Renewable Energy & Battery ESS
Utility-scale solar arrays and Battery Energy Storage Systems (BESS) require high ampacity earthing continuity, mechanical UV resistance, and waterproof reliability across a minimum 25-year operational lifecycle without maintenance degradation.
Mining & Heavy Infrastructure
Constant vibrational loads, mechanical abrasions, and risk of rock falls necessitate high-tensile brass construction with robust cable armor clamping cones to resist severe mechanical pull-out forces on heavy trailing cables.
Industry Trends: The Next Generation of Cable Gland Engineering
Examining material innovations, compliance evolutions, and smart connectivity reshaping hazardous-area termination.
Cold Flow Resilient Elastomers
Standard rubber seals can exert uneven pressure that induces "cold flow" or cable creep over prolonged operating lifecycles. Next-generation glands integrate diaphragm-style compensating inner seals that adapt to cable diameter fluctuations without crushing internal insulation or causing phase faults.
360° Low-Impedance EMC Shielding
With the rapid proliferation of variable frequency drives (VFDs) and high-current inverters in industrial automation, modern double compression glands incorporate phosphor bronze or stainless spring-loaded grounding rings, establishing uninterrupted 360-degree high-frequency shielding attenuation.
Universal Global Harmonization
Procurement teams increasingly eliminate regional multi-stock variations by adopting "Universal Multi-Certified" glands holding simultaneous ATEX, IECEx, UL, cUL, and EAC accreditations, alongside multi-thread adapters that facilitate fast cross-border system integration.
Frequently Asked Questions (Procurement & Technical FAQ)
Essential guidance addressing sizing selection, installation torques, hazardous zone compliance, and custom factory manufacturing capabilities.
What is the core distinction between Single and Double Compression Glands?
A single compression gland seals solely upon the outer sheath, providing mechanical cable retention and basic environmental ingress protection. A double compression gland clamps onto both the inner sheath and the outer sheath while securing the armor wires between two internal cones. This guarantees explosion containment (Ex d), gas tightness, and superior mechanical pull-out strength.
How do I select the exact gland size using the chart?
Measure three critical parameters from your cable datasheet: the Inner Sheath maximum outside diameter, the armor wire thickness, and the overall Cable Outside Diameter. Match the inner sheath first to ensure gas sealing integrity, verify the armor ring accepts your wire gauge, and finally confirm that the outer sheath falls comfortably within the outer compression range.
Can Metric threads be used on NPT threaded equipment entries?
Direct engagement is strictly prohibited due to differing pitch angles and taper configurations (Metric ISO 60° parallel vs. NPT 60° 1:16 taper). For enclosures with NPT female hubs, you must specify factory NPT gland entries or deploy certified Ex d thread conversion adapters (reducers/adaptors) with IP entry thread washers.
What materials are recommended for severe marine environments?
For standard offshore and marine platforms, high-tensile brass with electrolytic nickel plating (minimum 10-15 microns) provides excellent resilience. For continuous chemical immersion, splash zones, or high-salinity offshore wind substations, grade 316L (EN 1.4404) stainless steel is recommended to prevent pitting and crevice corrosion.
How does tightening torque affect IP68 and explosion-proof ratings?
Under-torquing fails to displace the internal elastomeric seal against the cable sheath, compromising both waterproof ingress and flamepath gap tolerances. Over-torquing can crush internal conductors or induce premature cold flow in the cable insulation. Always adhere to the recommended torque specifications provided in our engineering catalog.
Does HOONSUN accommodate OEM labeling and custom packaging?
Yes. As an authentic manufacturer since 2006, HOONSUN provides comprehensive OEM/ODM services. We offer custom laser marking on hex flats (part numbers, thread types, certification logos), bespoke packaging boxes, barcoding, and pre-assembled accessory kits (including locknuts, earth tags, and IP sealing washers).
Additional Heavy-Duty & Specialized Cable Terminations
Complete your procurement requirements with certified explosion-proof clamps, high-temp variants, and specialized breathable glands.
