Description
PAC-SH Series Heavy-duty Scotch Yoke Actuators are designed and manufactured in a variety of sizes, cylinder diameters, and configurations to meet different operational needs. They are available in both double-acting (DA) and spring-return (SR) models, making them suitable for installation on quarter-turn valves such as ball, butterfly, and plug valves.
These actuators are engineered to perform efficiently across a wide range of pressures and temperatures. The symmetric yoke design ensures a more consistent torque delivery throughout the stroke, particularly at critical points such as the breakaway and end positions.
Features
- Weatherproof Design: The PAC-SH Series Scotch Yoke Actuators are suitable for both indoor and outdoor installations. They can be customized for high or low-temperature applications by adapting the seals and lubricants to suit specific service conditions.
- Self-Lubricating and Wear Resistance: Both the guide rod and piston rod are hard chrome-plated to ensure superior wear resistance. The PAC-SH Series Actuators are permanently lubricated with materials and lubricants appropriate for the service environment, eliminating the need for maintenance under normal operating conditions.
- Corrosion Resistance: A three-layer epoxy coating is applied to every PAC-SH Series Heavy-duty Actuator to provide maximum protection against environmental corrosion.
Applications
- Chemical and Petrochemical
- Food and Beverage
- HVAC
- Marine
- Mining
- Oil and Gas
- Pulp and Paper
- Semiconductor
- Water and Wastewater
- Original Equipment Manufacturing
Construction
The PAC-SH Series Heavy-duty Scotch Yoke Actuators is designed with the latest engineering solutions, providing a safe and reliable driving mechanism for on-off or regulating applications. It is suitable for ball valves, butterfly valves, plug valves, and other 0°-90° rotating mechanical devices.
The actuator’s connection dimensions and torque range are compliant with ISO 5211 standards. It delivers a torque output of up to 250,000 Nm (184,000 foot-pounds). The shift fork design significantly reduces lateral loads, which greatly enhances performance and durability.
The modular structure of the actuator ensures excellent part interchangeability, simplifying use, maintenance, and reducing overall costs. Materials can be configured to suit the actuator’s operating temperature range, enabling reliable operation under diverse working conditions.
The cylinder module features a built-in guide rod that addresses local wear of the piston seal caused by the piston’s weight and the lateral forces from the shift fork. This ensures long-lasting, stable torque output.
Manual operating mechanisms are available as options, including:
Handwheel
Gear transmission
Hydraulic operation
The design offers symmetrical or tilted shift forks, allowing customers to choose the configuration that best fits their needs. The optimized transmission module and torque ratio provide enhanced adaptability to varying valve torque requirements.
The shift fork transmission mechanism uses oil-free lubricated bearings made of aluminum bronze composite graphite, delivering stable, long-lasting performance. Some connecting shaft holes utilize square shafts, improving precision and making the actuator especially suitable for regulating (control valve) applications.
For single-action operation, fail-open or fail-close functionality can be achieved efficiently by simply changing the direction of the cylinder and spring module.
Design Parameters
TORQUE RANGE
- Double-action: 250,000 Nm (184,000 ft-lbs)
- Single-action pneumatic: 250,000 Nm (184,000 ft-lbs)
- Spring: 110,000 Nm (81,000 ft-lbs)
For higher torque applications, please consult CONVALVE (customized torque range up to 800,000 Nm).
AIR SUPPLY PRESSURE
- 3.5-7 BAR (51-101 psi)
Please consult CONVALVE for special air supply pressure requirements. - Suitable for air, nitrogen, or other pure gases.
For pipeline medium gas supply applications, please consult CONVALVE.
TEMPERATURE RANGE
- Normal temperature: -29°C to 80°C (-20°F to 176°F)
- Low temperature: -40°C to 80°C (-40°F to 176°F)
- Ultra-low temperature: -60°C to 80°C (-76°F to 176°F)
- High temperature: -29°C to 160°C (-20°F to 320°F)
ADJUSTABLE STROKE
- 0-90° ± 6°
- Total stroke range: 80-100°
Design Standards
The PAC-SH Series Heavy-duty Scotch Yoke Actuators is designed and manufactured in compliance with the following international standards:
- EN 60529: IP66, IP66M, IP67, IP67M
- NEMA 250: NEMA 4, NEMA 4X
- EN 13906-1, EN 15714-3
- IEC 60079-0, IEC 60721-2-1, IEC 6150
- ISO 9001, ISO 5211, ISO 5599, ISO 12490, ISO 12944-2
Options
- Direct mount solenoid valves
- Monitor/Position confirmation limit switches
- Electro-Pneumatic positioner 4-20m input
- Pneumatic positioners 3-15 PSI input
