Archive: Feb 2018
DFT® is proud to announce the release of our new tapped lug, wafer style, check valve, the model TLW®. With its one-piece solid body construction and tight seal, this non-slam, center-guided check valve is designed to prevent leak paths and has the optimal safety feature of no exposed studs in the clamping area, which could impact the integrity of the valve in the event of a fire or corrosive environment.
Prevents Leak Paths, No Exposed Studs
This valve was originally designed for use in applications of the refining and chemical industry where exposure to fire, corrosion, and other harsh chemicals justifies the need to conceal studs, but is well-suited to any industry requiring no exposed studs.
Its tight seal and one-piece body prevents operating fluid leakage, allowing for safer more reliable operations
These TLW® axial flow check valves are lightweight and compact, meeting API 594 face-to-face dimensions. They can be installed in either a horizontal or vertical position, and used in liquid, gas, and steam pipelines.
They are built for a long life service life and low maintenance. For valves 10 inches or larger, tapped holes are included in the body, allowing lifting lugs to assist with installation.
Preventing Hydraulic Shock with TLW® Check Valves
As with all DFT® axial flow check valves, the TLW® has the ability to eliminate water hammer or hydraulic shock, the result of the generation of pressure waves in a pipeline, which occurs when the flow of the fluid is stopped by a sudden valve closure.
This pressure wave then travels back and forth through the pipeline, which can cause serious damage to pumps and piping systems. Such failures can be extremely costly, time consuming, and dangerous, especially if the pipeline is carrying toxic chemicals or high temperature fluids such as steam.
The TLW® check valves eliminate the problem of water hammer by using silent, spring-assisted technology. Unlike traditional check valves, TLW® valves do not rely on the velocity of operating fluid or gravity for valve closure. The disc is closed by the spring assist on the valve as the forward velocity of the fluid slows.
This coupled with the relatively short distance the disc must travel, by the time the forward velocity of the liquid reaches zero, the valve disc would already have reached the seat, and the valve will have already closed. Reverse flow is eliminated, and therefore the forces necessary to produce water hammer on the upstream and downstream sides of the valve are substantially diminished.
For optimal durability, the bodies of these valves are typically made of carbon steel or stainless steel. The disc, stem, bushing, and seat are made of stainless steel.
The valve is also equipped with a Nitronic® 60 stem and an Inconel® X-750 spring. These valves are available in sizes ranging from 2 inches to 24 inches and, as mentioned earlier, the larger models come with tapped holes for lift-assist lugs.
Our TLW® valves also feature a threaded lug design and raised face (RF) wafer ends, which assist in eliminating leaks. Well-suited for a wide range of applications, TLW® check valves help ensure safe operation in fluid pipelines.
DFT® has more than seventy years of experience in the manufacturing of check valves and control valves, and we strive to provide cutting-edge valve solutions for a wide range of industries, from chemical to wastewater processing. For more detailed information on our new TLW® check valves, download the product cut sheet today.