HS2D & HS2D+

Ultra‑fast mechanical protection for your transformers

Designed in accordance with NFPA 850 and aligned with IEEE, IEC and CIGRE guidelines to safeguard your critical power assets

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The Problem

Explosion Risk

Internal faults cause dynamic pressure waves that quickly convert to static pressure exceeding 10 bar, rupturing the transformer tank and igniting fires.

Current Solutions Are Slow

Dissolved gas analysis, pressure relief valves or flexible tanks react too slowly or designed to prevent transformer tank rupture. They often fail to prevent explosions and can be costly or unreliable.

Our Solution

HS2D — Fast Mechanical Trigger

HS2D open in less than 3 milliseconds, within 25 milliseconds after the short-circuit, venting pressure before static pressure builds. It’s purely mechanical for maximum reliability.

HS2D+ — Enhanced Safety

HS2D+ adds monitoring system and inert gas injection to sweep explosive gases. Activation remains mechanical.

Comparison

Feature	HS2D	HS2D+	Pressure Relief Valve
Activation	< 3 ms	< 3 ms	Slow
Activation after short-circuit for 400 MVA transformer	< 25 ms	< 25 ms	~ 85 ms
Inert Gas Injection	Optional	Included	None
Monitoring	Optional	Included	None
Standards	NFPA 850, IEEE, IEC, CIGRE *	NFPA 850, IEEE, IEC, CIGRE *	Varies

* Designed in accordance with NFPA 850 and aligned with IEEE, IEC and CIGRE recommendations.

Standards & Compliance

NFPA 850

HS2D meets the four criteria for Fast Depressurization Systems: passive mechanical operation, depressurization within milliseconds, activation by the first dynamic pressure peak and operation before static pressure rises.

IEEE & CIGRE

Designed in accordance with the reliability guidelines recommended by IEEE and CIGRE, favoring passive, redundant devices to safely relieve over‑pressure.

IEC 60076 & ATEX/IECEx Zone 2

Certified for use in Zone 2 hazardous atmospheres under ATEX/IECEx standards, HS2D operates with both mineral and natural ester oils on transformers from 1 MVA up to 1000 MVA and beyond.

Certifications

Manufactured under ISO 9001 and SGS certified.

Benefits & ROI

Safety & Resilience

Eliminate explosions, fires and environmental spills. Protect your workforce and critical infrastructure.

Cost Savings

Avoid multi‑million dollar losses from repairs, downtime and liability. Lower insurance premiums.

Retrofit & Scalability

Compatible with new or existing transformers from 1 MVA to 1000+ MVA. Modular design enables easy upgrades.

Environmental Protection

Prevent oil fires and toxic gas release. Supports biodegradable ester oils for greener operations.

Compliance & Liability

Meet NFPA 850, IEEE/CIGRE and IEC standards*. Demonstrate proactive safety to regulators and stakeholders.

Reputation & Trust

Invest in technology trusted by utilities worldwide. Enhance your brand image with proven safety leadership.

Ready to Protect Your Assets?

Contact us to schedule a customised risk analysis or to learn how HS2D & HS2D+ can be integrated into your fleet.

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