Product Overview
The Explosion-Proof Hexagon Metal Screw Plug (also known as a metallic stop plug or blanking plug) is engineered to permanently or temporarily seal spare cable entry holes in certified flameproof enclosures, junction boxes, and electrical cabinets.
Carrying Ex d IIC Gb explosion-proof certification, this heavy-duty screw plug prevents internal ignition propagation in Gas Zone 1 and Zone 2 hazardous areas (Gas Groups IIA, IIB, and IIC). Manufactured from high-grade 304/316 Stainless Steel or Nickel-Plated Brass, it features an IP68 ingress protection rating to block water, oil mist, and dust under extreme environmental conditions. With an extended thermal operating range of -60°C to +100°C (short-term up to 120°C), this plug delivers reliable, gas-tight sealing for oil & gas refineries, chemical processing, and military-grade electrical systems.
Key Features
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Ex d IIC Gb Certified Flameproof Protection: Approved for use in dangerous Gas Zone 1 and Zone 2 environments covering Gas Groups IIA, IIB, and IIC.
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IP68 Ingress Protection Rating: Provides maximum water-tight and dust-tight performance to protect internal electrical components under high washdown and harsh outdoor weather.
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Premium Material Options: Available in heavy-duty Nickel-Plated Brass (for optimal cost efficiency and oxidation resistance) and SS304 / SS316 Stainless Steel (for superior chemical and salt-spray corrosion resistance).
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Extreme Thermal Resilience: Performs continuously across operating temperatures from -60°C to +100°C (withstands short-term temperature spikes up to 120°C).
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Hexagon Head Design: Features an external hex drive profile allowing easy, high-torque installation and removal using standard wrenches.
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Universal Thread Compatibility: Precision-machined in Metric (M), NPT (ANSI), and G (BSP) thread configurations to match international electrical enclosure ports.
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Standard Compliance: Manufactured in strict accordance with GB3836.1, GB3836.3, and IEC 60079 explosion-proof standards.
Applications
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Oil & Gas Refineries & Extraction Rigs: Safely sealing unused entry ports on explosion-proof control boxes, terminal panels, and switchgear in onshore/offshore facilities.
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Chemical & Petrochemical Processing: Long-term sealing for electrical enclosures exposed to aggressive chemical vapors, acids, and high humidity.
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Military & Defense Engineering: Heavy-duty protection for specialized power distribution boxes requiring certified Ex d containment and impact resistance.
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OEM Cabinet Builders & Contractors: Sealing spare knocked-out entry holes during field installation or facility upgrades to ensure ongoing Ex compliance.
Technical Specifications
| Parameter | Specification Details |
| Product Name | Explosion-Proof Hexagon Metal Screw Plug / Stop Plug |
| Explosion-Proof Mark | Ex d IIC Gb |
| Protection Rating | IP68 |
| Hazardous Zones | Zone 1, Zone 2 (Gas Groups IIA, IIB, IIC) |
| Material Options | Nickel-Plated Brass, 304 Stainless Steel, 316 Stainless Steel |
| Operating Temperature | -60°C to +100°C (Short-term up to 120°C) |
| Interface Threads | Metric (M), NPT (ANSI), G (ISO 228-1 Parallel) |
| Design / Head Type | Hexagon Head |
| Implementation Standards | GB3836.1, GB3836.3 (IEC 60079 compliant) |
| Customization | Custom thread lengths, laser markings, and materials available |
Product FAQ
Q1: What is the main purpose of an explosion-proof metal screw plug?
An explosion-proof screw plug (or stop plug) is used to close off unused cable entries on an Ex-rated enclosure. It ensures that the enclosure retains its flameproof integrity (Ex d IIC Gb) and prevents flames or hot gas from escaping into surrounding hazardous areas.
Q2: Should I choose Nickel-Plated Brass or Stainless Steel (SS304/SS316)?
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Nickel-Plated Brass: Ideal for general industrial automation, standard factory environments, and outdoor control boxes with good atmospheric oxidation resistance and high cost-efficiency.
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SS304 / SS316 Stainless Steel: Recommended for aggressive chemical environments, marine/offshore platforms, washdown zones, and places exposed to high salt spray or strong acid vapors.
Q3: How does this screw plug achieve an IP68 protection rating?
The combination of precision CNC-machined thread tolerances and a durable elastomeric sealing washer at the plug shoulder creates a tight barrier against water submersion, high-pressure spray, and dust particles.
Q4: Are custom thread sizes or laser markings available for bulk orders?
Yes! As a direct manufacturer, XW Electric provides OEM/ODM services, including specialized thread sizes (Metric, NPT, G), extended thread lengths, custom laser-etched specifications on the hex head, and specialized packaging.
