Nudango pitches trapped-key valve interlocks for hazardous industrial sites

Shanghai Nudango Safety Equipment is promoting trapped-key valve interlock systems designed to prevent incorrect valve sequencing in oil and gas, petrochemical, marine, and power applications. The company says its products combine stainless-steel durability, explosion-proof compliance, and modular controls for complex pipeline and isolation systems.

Why it matters: - Incorrect valve sequencing can trigger leaks, explosions, or production shutdowns in oil and gas, petrochemical, marine, and power generation operations. - Mechanical interlocks are meant to physically prevent operators from bypassing required safety steps. - Nudango is positioning its valve interlock systems as a safety layer for critical processes where human error can have high consequences.

What happened: - Shanghai Nudango Safety Equipment Co., Ltd. introduced its trapped-key valve interlock technology and related explosion-proof options on July 9, 2026, in Shanghai. - The company markets the systems under the Nudango name and describes itself as a manufacturer of valve interlocks, safety planning, and system solution design. - Nudango lists certifications including ISO9001, ISO14001, ISO45001, and CE. - The company says it exports to more than 15 countries, including Germany, Saudi Arabia, and Brazil.

The details: - The trapped-key system uses a uniquely coded key to lock or unlock valves in a fixed sequence. - A key is released only when a valve is in the correct position, then used to access the next valve in the sequence. - Nudango says its Sequential Control Unit centralizes key management and can control multiple valve interlocks from a single panel. - The company builds load-bearing components from 316L stainless steel and offers optional PTFE or electroless nickel anti-corrosion treatments. - Nudango says the corrosion-resistant design is intended for offshore platforms and chlor-alkali plants and has passed salt spray testing of 500 hours or more. - For hazardous areas, Nudango offers explosion-proof models for Zone 1/2 and Class I/II environments. - The explosion-proof units are described as conforming to ATEX Directive 2014/34/EU and IECEx standards. - The harsh-environment range is rated for ambient temperatures from -40°C to +80°C. - The portfolio includes quarter-turn valve interlocks for ball, butterfly, and plug valves; multi-turn models for gate, globe, and diaphragm valves; drive valve interlocks for actuators or gearboxes; gearbox-mounted interlocks; and limit interlocks for position feedback and key release confirmation. - Nudango says the lineup covers DN15 to DN600 valves, pressures up to PN420, and torque ranges from 50 Nm to 2000 Nm depending on the model. - Technical parameters listed by the company include valve compatibility for ball, butterfly, gate, globe, plug, and diaphragm valves; nominal diameter from DN15 to DN600; pressure rating up to 420 bar or Class 2500; explosion-proof rating Ex d IIC T6; and special temperature capability up to +150°C. - The company also lists 316L stainless steel as the base anti-corrosion material, with optional duplex stainless steel, Hastelloy, or coated carbon steel. - All products undergo 100% functional testing before shipment, according to the company. - Nudango says more than 50,000 interlocks have been deployed worldwide. - The company says its systems have been used in projects across the Middle East, Southeast Asia, and Europe. - Contact details listed in the release include Eirlys, global004@shndg.cn, +86 17372513256, WhatsApp +86 17372513256, and the website More information.

Between the lines: - Nudango is selling safety hardware, but the pitch is also about process standardization and traceability across complex industrial systems. - The combination of trapped-key sequencing, corrosion resistance, and explosion-proof certification suggests the company is targeting high-risk sites where downtime and equipment failure are especially costly. - The breadth of materials, ratings, and valve types indicates a strategy built around customization rather than a single universal product.

What's next: - Nudango says it will continue providing customized design support and on-site installation guidance for industrial customers. - The company is likely to focus on sectors and regions that require certified equipment for hazardous or corrosive environments. - Wider adoption will depend on whether buyers accept the systems as a practical alternative to other safety-control methods.

The bottom line: - Nudango is framing trapped-key interlocks as a mechanical safeguard for industries that cannot afford valve-sequencing mistakes.