Combined Check Valves
Combined Check Valves or Hydraulic actuators weight loaded HAWL valves are used at all critical areas where the pipelines must be reliable, immediate and controlled quickly for valve closing, e.g. in case of external power losing, cutting off electricity cables during the earthquake, disasters in a system, ruptured pipelines, etc.) While for the valve closing is used a potential energy of lifted weight. The counterweight and lift cylinder shut-off valve is used to stop the water on the pipelines automatically. The pipeline shut-off function must be guaranteed under hardest condition of maximum flow rate or pressure and in case of electric power failure. The movement of the shut-off device (butterfly, ball valve, needle valve) is guaranteed by means an hydraulic actuator composed by hydraulic cylinder to maintain the valve open and a counterweight to close the valve.
Design Features
- Hydraulic actuator with counterweight for fast and reliable valve closure
- Modular compact design with ISO 5211 mounting for easy installation
- Special lever bearing design to protect the valve shaft
- Autonomous operation with integrated hydraulic power unit
- Reliable electro-hydraulic unit for opening and holding valve position
- Custom hydraulic and pneumo-hydraulic power pack options available
- Emergency hand pump for forced manual valve opening
- Environmentally responsible design to prevent oil contamination
- Separate modular weight and lever for flexible configuration
- Standard end-position micro-switches for valve status monitoring
- Optional rotary encoder and additional micro-switches
- Intelligent design with sensors for flow and pressure control
- Adjustable damping stages for controlled closing performance
- Automatic safety shut-off for pipeline protection
- Available in normally open or normally closed electro-hydraulic control systems
- Adjustable closed position with fixed mechanical limiters
- Adjustable open position with self-aligning clevis
- Adjustable opening and closing time for precise control
- Service pin locking for maintenance safety
- Designed for high-performance Applications
Material Standards
Body, Disc, Gland and Bottom Cover ——— Ductile Iron EN-GJS-500/7 Or Ductile Iron EN-GJS-400/12 Acc. To (EN1563)
Body Seat ——— Stainless Steel Grade 309L
Retaining Ring ——— Stainless Steel Grade 316
Disc Seal ——— EPDM Rubber
Driving Shaft & Stub Shaft ——— X20Cr13 (AISI 420)
Valve Bearing ——— Self-Lubricating Bearing (PTFE/Steel/Tin)
Body Sleeve, Disc Sleeve (Dry Shaft Mechanism) ——— Bronze