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Серия SD

SD Series Gear Box – Manual Override Gearbox for Valve Automation

What Is the SD Series Gear Box?

The JSW SD series gear box is a separable right‑angle gear drive designed for manual override of pneumatic or electric actuators. Its housing features precision castings, making the unit suitable for manual operation of ball valves, butterfly valves, and plug valves when an actuator fails or during maintenance. This gearbox is driven by a worm gear mechanism and features a self‑locking function for safe positioning. Additionally, it adopts tapered roller bearings, which makes operation more convenient and efficient. The mounting flange follows ISO 5211 international standards, enabling straightforward installation with quarter‑turn valves. The overall protection grade reaches IP67, with IP68 available for some special environments. For more information about our company, please visit our about us page.

Key Technical Specifications

Below are the key technical parameters that define the performance of this manual override gearbox:

Mounting Standard: ISO 5211 – enables direct flange installation with quarter‑turn valves without additional adapter brackets.
Protection Rating: IP67 standard, with IP68 optional for temporary submersion and demanding environments.
Mechanism: Worm gear drive with self‑locking capability for safe positioning at any angle.
Bearings: Tapered roller bearings – provide smooth, efficient, and durable operation.
Housing Material: Precision castings – lightweight yet robust.
Stem Nut: Customizable as a positive or separate structure according to customer requirements.
Output Drive: Interchangeable output drive bushings offer versatility.
Temperature Range: Standard -20°C to +80°C, with extended options available.
Lubrication: Grease filled for life – maintenance free.

For detailed product drawings and dimensional data, please contact our technical team.

Product Features – Why Choose This Gear Box for Your Application

This manual override gearbox offers several key advantages for valve automation applications:

Separable Right‑Angle Design: The separable design allows easy insertion between an actuator and a valve, simplifying installation and maintenance procedures.
Self‑Locking Worm Gear: The worm gear mechanism provides automatic self‑locking, ensuring the valve stays securely in position without the need for additional holding devices.
Dual Functionality: It functions as both a manual override gearbox and a standard gear operator, eliminating the need for separate components and reducing overall system complexity.
Efficient Operation: Tapered roller bearings and a precision‑machined worm shaft maximize mechanical advantage, reducing operator effort.
ISO 5211 Compliance: Compliant with ISO 5211, the global standard for quarter‑turn valve automation mounting interfaces, enabling straightforward installation on a wide range of valves.
Environmental Resistance: IP67/IP68 protection allows this unit to withstand temporary submersion and resist dust ingress, making it suitable for outdoor and washdown applications.

Working Principle – How It Functions

The gearbox operates on a simple yet effective worm gear principle. First, turning the handwheel drives the worm shaft, which rotates the worm wheel and output drive. Then, the separable design allows the unit to be inserted between a pneumatic actuator and a valve. When the actuator operates normally, the gearbox rotates freely. However, during actuator failure or maintenance, the manual override function engages, enabling precise manual valve positioning.

A declutchable gear operator offers a simple and reliable method for local manual operation. For example, a block and bleed valve automatically exhausts air from the actuator to override the remote control system when manual operation is required. Moreover, the self‑locking worm gear ensures safe and easy operation, positive manual positioning, and long service life. Therefore, this unit works with any quarter‑turn actuator and installs directly onto existing valves in the field.

Applications – Where to Use This Manual Override Gearbox

Our manual override gearbox serves a wide range of applications requiring reliable manual valve operation. Specifically, common applications include:

Emergency Shutdown (ESD) Systems: Provides a dependable manual override for pneumatic actuators on isolation valves in refineries, pipelines, and chemical plants.
Water and Wastewater Treatment: Operators use it on large‑diameter butterfly valves where actuator failure would disrupt plant operations.
Oil and Gas Pipelines: Remote valve stations rely on it as a reliable manual backup for block and bleed valves.
Power Generation Facilities: Works on cooling water systems, steam isolation valves, and fuel handling systems.
HVAC Systems: Controls dampers and valves in large commercial and industrial buildings.
Shipbuilding and Marine Engineering: Applications include ballast water management systems, fuel transfer lines, and firemain isolation valves.
Pneumatic Actuator Systems: Integrates with a pneumatic actuator to add reliable manual backup for critical valve applications.
Chemical and Petrochemical Industries: Provides manual override on corrosive media handling valves.

Quality Assurance – Our Commitment to Excellence

As part of the SINOTEST group and a certified manufacturer, our SD series gear box meets internationally recognized quality management systems. Specifically, JSW has obtained ISO 9001:2015, ISO 14001:2015, and ISO 45001:2018 certifications. These cover our quality management, environmental practices, and occupational health and safety systems. Additionally, we hold AEO certification – this streamlines international customs clearance for our export customers. For detailed certification documentation, please visit our certificates page.

Customization Options

JSW offers customization for this gearbox to meet specific customer requirements. For instance, we can modify the stem nut into a positive or separate structure based on application needs. This gearbox can also be configured with special output drive bushings, extended temperature range versions for extreme environments, and alternative housing materials such as stainless steel for food and pharmaceutical applications. For more information about customization, please contact our engineering team.