What are Tilting check valves

Tilting check valves are one of the most common types used in clean water, turbid water and irrigation water applications for the benefits provided by this type of valves. They are either equipped with a lever and a lowering or equipped with a hydraulic brake.

The use of these valves depends on the second principle, which is to close the valve slowly by using a hydraulic brake. This causes a quantity of water to pass to the pump, causing the pump to rotate in the opposite direction of its rotation.

Design characteristics of Tilting check valves

Tilting check valves are relatively better than swing check type valves, as some modifications have been added to the design shape:

• The distance between the center of the disc and the center of the rotating shaft eccentricity is less than that of swing check valves. That generates a relatively lower torque. When the water column collides with the disc when closing, the moment of inertia generated when closing is relatively large, this is due to the location and position of the disc suspension.
• The opening angle of the valve ranges from 60° to 80°. That is, the valve travel from fully open to fully closed is relatively large. This makes it susceptible to disc impact when closing. Tilting check valves are not suitable for sewer applications. This valve is not recommended for wastewater applications because the pins that extend into the flow stream tend to collect debris. Clean water or treated wastewater is best for this valve.

Video Tutorial of How Tilting Check Valves Work and Their Different Parts

Tilting check valves are designed to prevent flow reversal in a piping system. These valves are activated by the flowing material in the pipeline.

The pressure of the fluid passing through the system causes the valve to open, while any reversal of flow will close the valve. Closing is accomplished by the weight of the check mechanism, back pressure, a spring, or a combination of these means. Common types of check valves are the swing valve, tilt disc valve, piston valve, butterfly valve, and stop valve.

The tilted disc check valve is similar to the swing check valve. Like the swing check valve, the tilted disc type keeps fluid resistance and turbulence low due to its straight design.

Tilted disc check valves can be installed in horizontal and vertical up-flow lines.

Some designs simply fit between two flange faces and provide a compact and lightweight installation, especially on larger diameter valves.

The disc lifts off the seat to open the valve. The disc’s aerodynamic wing-shaped design allows it to “float” on the flow. The disc’s integrated stop in the body positions the disc in an optimal position for flow characteristics. The large body cavity helps reduce flow restriction.

As flow decreases, the disc begins to close and closes before backflow occurs. Back pressure against the disc moves through the soft seal to the metal seat for a tight seal without slamming shut.

If backflow pressure is insufficient to cause a tight seal, the valve can be equipped with an external lever and weight.

These valves are available with a soft seal ring, a metal seat seal, or a metal-to-metal seal. The latter is recommended for operation at high temperatures.

Soft seal rings are replaceable, but the valve must be removed from the line to perform the replacement.

Pros and Cons of Check Valves

Check valves are generally one of the most important valves in water and sewer pumping systems. Their purpose is to open automatically when the pumps are running and return to the closed position to prevent backflow when the pumps are not running. These valves help reduce energy consumption and protect the pumping system from pressure surges and damage caused by backflow.

Choosing check valves for a process is similar to choosing hardware for new tanks. Once you have decided on a handle, there are a variety of styles, colors, and price points to consider. It’s the same with check valves. Obviously, the process you’re working on requires a check valve, but which one? Each style of check valve is designed to meet a specific need. Here are the pros and cons of some of the different types of check valves.

Lift Check Valves

Lift check valves are commonly used in high-rise buildings, industrial applications, power plants, and water and sewer applications. They have no external moving parts and are known to be economical and reliable. Over time, the energy costs of these types of valves can be high because the disc remains in the flow stream during operation.

Ball Check Valve

Ball check valves are commonly used in water and wastewater applications. These valves are easy to operate, compact and economical. These valves feature a rubber-covered ball that moves in and out of the seat as the flow moves back and forth.

Because the ball travels a long distance when the pump is turned off, these valves tend to close in high-pressure applications.

Swing Check Valves

Swing check valves are certainly the most common check valves used in water and wastewater pumping systems. They are readily available and relatively inexpensive. They are also automatic, do not require an external power source, and are driven only by the direction of flow.

Double Disc Check Valve

These valves can come in a few different configurations, and operate in the same basic way.

This check valve features a wafer body design and two D-shaped discs that rotate out of the way when flow enters the valve. It has good non-closing properties but is not recommended for wastewater applications. It is also susceptible to vibration and corrosion.

Traditional Check Valve

It is certainly the most common check valve in water and wastewater applications

Sanitary. This type of valve usually has a metal or flexible seat and a swing angle of 60-90 degrees. This valve tends to close, but due to the long stroke, friction in the packing and inertia of the disc.

Airbags are sometimes used to help relieve the closure. Although some believe that a lever and spring are better accessories because they allow the valve to close faster.

Tilting check valves

The difference between a tilted disc check valve and a traditional swing check valve is that flow is allowed to pass through both sides of the disc. Because of this, it allows for very low head loss.

This valve is not recommended for wastewater applications because the pins that extend into the flow stream tend to collect debris. Clean water or treated waste is best for this valve.

Do you have the right type of check valve for your application? Could there be a better valve? Always discuss changes to your pumping system with an engineer who has good experience with all types of check valves. He may be able to help you find valves that close less often or that may be more energy efficient. Our CareWater team is happy to answer any questions you may have about water treatment plant valves.