History of the ‘Basic-Check’ Valve

Since its initial development, the check valve has evolved from a classified request from the U.S. Navy to becoming a staple in flow control systems, allowing operators to easily stop reverse flow and water hammer while providing tight metal-to-metal closure. Some of the first all-stainless steel valves were engineered for use with cryogenic liquids and facilitated the development of the first nuclear weapons. Since then, check valves have grown into a fundamental element of fluid system design across a range of applications.

Roots in Reliability: Durabla® & the U.S. Navy

Originally known as Durabla Manufacturing Company, which manufactured pump valves, Durabla developed a reputation early on in the industry for both superior quality and innovation. Eventually, the company would split into Durabla Fluid Technology (DFT®), which focuses on check valves, and Triangle Pump Components Inc., another division dedicated to reciprocating pump components production. 

Throughout the 1920s and 1930s, Durabla nurtured a strong relationship with the U.S. Navy, which eventually requested a classified internal check valve design that could hold up in cryogenic temperatures. 

A Classified Beginning: The Birth of the Basic Check Valve

With the Government’s request for a unique temperature-resistant valve for the then-classified Manhattan Project, the concept of the Basic-Check Valve was born. This iteration of the valve could withstand some of the lowest temperatures and provide tight closure to keep equipment functioning properly in a cryogenic environment. 

The uniquely durable and lightweight disc-shaped design of the Triangle Pump pump valves enabled them to last longer, which led the Military to request a similarly designed check valve that could replace less reliable elastomer valves for use with cryogenic liquids.

Declassified & Delivered: Post-War Innovation

By the early 1950s, the U.S. government had disclosed the Manhattan Project to the public, allowing for further development of DFT®’s proprietary check valve design.  The basic check valve design worked across numerous applications involving extreme temperatures. Unlike elastomeric designs, these check valves could withstand high and low temperatures in many commercial and industrial environments, making them a standard option for various industries.

Legacy & Evolution

In the years since its declassification and widespread commercialization, the basic check valve has evolved in different ways to meet applications’ varying needs.

For example, some DFT® clients have requested a valve that would remain closed until it reached a specific pressure level, which led DFT® to develop a restrictor check for use in steam systems and other applications. This involved installing a stronger spring in the existing basic check valve design. The reliable design of the basic check valve also contributed to a vacuum breaker design that could prevent steam leakage in textile systems and ensure the valve opened reliably.

Today, the versatility and overall quality of DFT®’s basic check valve design has become a go-to solution in the industry – setting DFT® apart for the company’s consistent quality, reliability, and performance. You can now find these valves in the following:

• Autoclaves
• Cooling towers
• Cookers
• Chemical lines
• Evaporators
• Hydraulic lines
• Refrigeration
• And more

Innovation over the years

DFT® continues to innovate with different variations of the basic check valve design. One such innovation entailed the development of our SCV Check Valve, which consolidates two components into a single one to prevent water hammer and provide tight closure in 1/2″ to 3″ pipes. Through this innovation, the company continues to honor its roots by ensuring the ongoing quality and reliability of DFT®’s check valve design.

Reliable Check Valves From DFT® Inc.

What began as a little-known component for an exclusive research enterprise has since grown into a globally ubiquitous product. DFT®’s basic check valve continues to be installed and used in many systems, with multiple iterations of its design across several high-quality DFT® products. Whether you need one of our in-stock items or a special order to meet your unique application requirements, we’re here to direct you toward the right solution.

Want to find out more about our check valves and control valves? Contact us today to speak with a member of our team or request a quote for a standard or custom order.

The Special Cleaning Needed for Cryogenic Valves

Cryogenic valves are intended for use in extremely cold applications, the term cryogenic generally is applied to temperatures below -50^oC. Valves for cryogenic service have to be constructed of materials that retain their ductility at these very cold temperatures as well as special gaskets and seals that are suitable for extremely cold temperatures. Industries that deal with liquefied and compressed natural gas, as well as liquid Oxygen, Nitrogen or Helium rely on these specialty valves frequently to move cryogenic liquids and gases safely and reliably.

Usually, cryogenic check valves use the pressure of the fluid flow to push the valve into an open position, which allows gas, the media to flow through. When fluid flow pressure decreases, the valve will close again and form a seal in order to prevent leakage through the valve.

Special Cleaning and Concerns

Cryogenic valves require special cleaning and degreasing by the valve manufacturer.  This is accomplished with special solvents to degrease and remove any organic contaminants, and often by using ultrasonic cleaning solutions. Some services like oxygen or chlorine service require very high levels of cleanliness to insure that no organic materials or lint fibers are present after cleaning.  Properly cleaned and certified valves are placed in double sealed polyethylene bags to insure that the valve remains cleaned until it is time to install the valve.

Operators should always thoroughly inspect cryogenic valves before installing them. This is critical to ensure that no oil or grease has been accidentally introduced into the valve. Some specialized lubricants are approved for oxygen service; their presence may be allowable, but this varies by application.

As mentioned earlier, cryogenic valves must also be kept free of lint. Generally speaking fibers greater than 1/8” in length are not allowed to be present in the cleaned valve. In many cases, absolutely no fibers or lint can are allowed to be present regardless of length. Debris like this can prove dangerous in oxygen systems. Many industry professionals utilize blacklight testing to help detect fibers.

Finally, inspectors must regularly check cryogenic valves and oxygen systems for both internal and external leakage. Internally, leakage can be prevented by ensuring that the proper valve is in place and that it has a well proven sealing design. Cryogenic conditions in particular require robust seals to boost longevity. External leakage is also a significant concern.  Often times weld end designs are required.  These can be in the form of butt weld ends or socket weld ends on the valves.

How DFT® Can Help

DFT® offers high quality, In-Line, Axial Flow designed check valves as well as a full line of severe service control valves. Our customers often specify weld-end valves for a greater sense of security, but flanged and wafer-style valves are also used. DFT’s GLC, WLC and BNC model check valves and our HI-100 model control valves are suitable for a wide variety of cryogenic applications.

Learn More About DFT’s Valve Solutions

With over 80+ years of experience in valve manufacturing, DFT® is proud to offer our clients world-class products at affordable prices. Our certified, knowledgeable staff helps customers overcome obstacles and create custom solutions that will maximize the potential of their valve systems. If you would like to learn more about cryogenic valves, keep an eye out for our upcoming eBook, “Cryogenic Valves 101.”