Time：2025-11-19 11:18:28 Browser 2 Origin：本站
The SOLDO SQ series limit switches feature a compact design with visual position indicators. Available options include mechanical, proximity, solid-state, and pneumatic switches, as well as HART, FF, PROFIBUS, and 4–20 mA bus communication protocols.It covers product series including SK, SQ, SY, SF, SS, SB, SA, BM, etc. The SOLDO SQ series is constructed of 316L stainless steel with chromate conversion coating and polyester powder coating (electroplating finish). It is equipped with UV- and VO-resistant polycarbonate 3D position indicators and stainless steel shafts. Compatible with single-acting and double-acting actuators, the unit integrates low-power 3/5-way solenoid valves and anti-vibration brackets, supporting universal mounting configurations, threaded connections, and VDI/VDE 3847 standard pneumatic output circuits.SOLDO provides customers with complete process control solutions for valves and customizes valve limit switch boxes tailored to customers’ operating conditions. Shengweike is a supplier of fluid control solutions and control valve products, offering complete control valves, complete on-off valves, pneumatic circuit control schemes, electrical circuit control schemes, and automated valve products.
Liquefied Natural Gas (LNG) projects are high-risk and highly complex energy engineering ventures, imposing stringent requirements on automated valve control: accurate status feedback, stable operation, explosion-proof safety, and remote monitoring capability.
Zhuhai Sevicon (SEVICON) has extensively deployed the SQ series limit switches within LNG fluid control systems to develop integrated solutions featuring high reliability, low maintenance costs and compatibility with domestic localized equipment.
I.Structural and Performance Advantages of SOLDO SQ Series Limit Switches
As industrial-grade valve position feedback devices, the SOLDO SQ series is specially designed for hazardous working conditions and frequent start-stop systems, featuring the following core characteristics:
Explosion-proof Design: Compliant with ATEX and IECEx explosion protection standards, suitable for hazardous areas such as LNG storage tanks and pipelines. High Ingress Protection Rating: IP67/IP68 rating, capable of long-term operation in coastal environments with high humidity and heavy salt spray. Corrosion-resistant Housing: Available with hard-anodized aluminum alloy with polyester coating or 316L stainless steel housing, suitable for severely corrosive service conditions. Dual Cam/Sensor Structure: Mechanical cam positioning paired with inductive switch feedback for accurate and stable signal output. Diversified Interfaces: Optional SPDT microswitches, proximity switches and solid-state relay outputs, compatible with various PLC and DCS systems. Intuitive Indication: 360° viewing window displays valve open/close status for convenient on-site inspection.
These advantages make the SQ series particularly ideal for critical links involving real-time position feedback and safety interlocks in LNG projects.
II.Practical Application of SQ Series Products on Valves in LNG Projects
Integrate SQ series position transmitters into multiple automated LNG valve scenarios with practical engineering case studies.
1.Application of SOLDO SQ Series Products on LNG Vessels
Soldo SQ position transmitters provide status feedback for manual ball valves and butterfly valves.
Interlock with pneumatic actuators and emergency shutdown systems to realize automatic shutoff upon air loss and remote signal transmission.
Equipped with explosion-proof certification and corrosion-resistant housing to ensure long-term stable operation in tank farms.
2.Application of SOLDO SQ Series Limit Switches in LNG Terminal Loading Arm Systems
Equipped with SOLDO SQ position transmitters and limit switches to provide real-time feedback on the open/closed status of unloading valves
Integrated with DCS control cabinets to realize dual local and remote monitoring.
Enhance safety and traceability throughout the unloading operation.
2.Vaporization Units and Pipeline Pressure Regulation Systems
SOLDO SQ signals are connected to the PLC system together with surge protection SPD modules to deliver remote monitoring and safety interlock functions.
Suitable for LNG transportation working conditions featuring low temperature, explosion-proof and moisture-proof requirements.
III. Key Points for Installation and Protection
Matters Needing Attention for Installation and Protection of SOLDO SQ Series Position Feedback Switches：
Standardized Installation: Adopt NAMUR standard brackets to enable quick compatibility with various actuators;
Signal Protection: Install SPDs at the front end of signal cables to resist lightning strikes and surge interference;
Equipotential Bonding: Establish equipotential connections for all circuits to reduce risks of induced voltage;
Explosion-Proof Specifications: Perform wiring in strict accordance with IEC and GB explosion-proof requirements to ensure safe operation in hazardous areas;
System Commissioning: Conduct multiple on-off cycle tests to guarantee synchronization between feedback signals and valve movements.
IV. Integrated Valve Automation Services of SEVICON
Zhuhai Sevicon (SEVICON) not only supplies high-performance SQ series position transmitters, but also delivers complete valve automation solutions.
Turnkey supply and installation of actuators and position feedback switches;
Design and assembly of explosion-proof control cabinets;
Adaptation of remote communication protocols (Modbus, Profibus, 4–20 mA, etc.);
EMC testing, explosion-proof certification and on-site commissioning support for LNG working conditions
Full-lifecycle services for valve systems
Driven by both technology and service, SEVICON takes full advantage of domestic production to deliver safe, reliable and cutting-edge automated fluid control solutions for LNG and other energy customers.
SOLDO limit switches feature a compact design and visually effective indicators, with options including mechanical, proximity, solid-state, pneumatic switches, and communication protocols such as HART, FF, PROFIBUS, and 4-20mA bus. The product range includes series such as SK, SQ, SY, SF, SS, SB, SA, and BM. The SOLDO SK70 series is made of stainless steel 316L and coated with corrosion-resistant salt and polyester powder (plating treatment), with UV-resistant and VO-rated polycarbonate 3D indicators, stainless steel shafts, suitable for single-acting and double-acting actuators, low-power 3-way or 5-way solenoid valves, shock-resistant frames, standard installation setups, threaded and VDI/VDE3847 pneumatic output lines. SOLDO can provide customers with comprehensive solutions for valve process control procedures and customize limit switch boxes according to the customer\'s operational conditions. Sevicon (SEVICON) is a supplier of fluid control solutions and control valve products, including complete sets of control valves, full sets of switch valves, as well as pneumatic control solutions, electrical control solutions, and automatic control valve products.
