Check valves are essential components in pipelines and hydraulic systems that prevent reverse flow. They allow fluid flow in the normal forward direction but close when flow tries to reverse. This ensures one-way flow and protects equipment from damage due to backflow. The tilting disc check valve is a durable swing-type check valve that provides reliable backflow prevention through its simple, efficient operating principle.
Operating Principle
Tilting disc check valves consist of a disc attached to a hinge inside a tubular valve body. The hinge is located at a small angle offset from the centerline of the valve. This causes the disc to also sit at a slight angle to the flow when fully open.
As forward flow enters the valve, the disk tilts open allowing unobstructed passage. A full pipe bore is exposed with minimal flow resistance. As flow reverses, backpressure forces the disc back onto its seat, providing a tight seal and preventing backflow. This reliable closure is ensured by having the reverse flow pushing upwards against the disc tilting it into the seat.
The tilting action is more effective compared to a centered swing disc that can flutter and bounce against the seat. The offset hinge gives the disc a definitive opening and closing motion for reliable operation.
Key Features Of Various Check Valves
- Full Bore Flow – The disc tilts through 90° to provide an unobstructed flow path. Minimal pressure loss.
- Tight Shutoff – The disc seals reliably against backflow with minimal reverse leakage. Resilient seats provide bubble-tight shutoff.
- High Capacity – Available in large sizes up to 60 inches and capable of handling very high flow rates.
- Simple Mechanism – No complex linkages. Disc is directly attached to a sturdy hinge. Reliable and rugged.
- Safe Operation – Disc movement damped near the closed position to prevent slam and water hammer.
- Low Headloss – Streamlined disc profile and smooth contours minimize turbulence and resistance.
- Self Actuating – No external power source required. Responds passively to flow changes.
- Maintenance Free – No lubrication needed. All parts are self-cleaning.
- Compact Design – Smaller than many check valves. Reduces space requirements.
These valves are available in different designs based on the orientation of the disc and seating. The principal configurations are:
- Horizontal Disc – Most common. Disc hinge is horizontal. Used in horizontal lines.
- Vertical Disc – Disc hinge is vertical. Used in vertical piping.
- Dual Plate – Uses two opposing discs. Bi-directional sealing for horizontal lines (dual plates check valve).
- Nozzle Check – Disc attached directly to the end of a nozzle. Acts as a combined control valve and check valve.
Tilting disc valves can be supplied with various body styles and end connections. Wafer type check valves are compact and install between pipe flanges. Lugged valves have flanged ends and are used to replace existing gate or globe valves.
Applications Of Tilting Disc Check Valves
The key application for tilting disc check valve is preventing reverse flow and back pressure surges in pipelines. They reliably hold upstream pressure with minimal leakage.
Specific uses include:
- Pump Discharge – Protect against backflow when pump is shut off. Avoid motor damage.
- Branch Lines – Prevent discharge from larger headers backfeeding smaller lines.
- Equipment Protection – Shield components like control valves, meters, and blowers from damaging backpressure.
- Water Hammer Control – Safeguard against slam and surges during closure.
- Compressor Suction – Stop recycled compressed gas. Avoid impeller damage.
- Column Separation – Prevent drain-down of vertical pipe sections.