--- title: The Check Valve Hasn’t Changed in 50 Years description: The check valve you specify today can create the surge problem you troubleshoot tomorrow. Here’s what most engineers miss about swing check valves and modern alternatives. image: https://www.environmental-md.com/hubfs/Large%20Check%20Valves.png --- [Skip to content](https://www.environmental-md.com/blog/the-check-valve-hasnt-changed-in-50-years#main-content) [![Environmental MD Inc., a DXP Company](https://www.environmental-md.com/hs-fs/hubfs/CVI-EMD%20Logo%201.png?width=910&height=325&name=CVI-EMD%20Logo%201.png)](https://www.environmental-md.com) - [Home](https://www.environmental-md.com/) - Products Show submenu for Products - [Manufacturers](https://www.environmental-md.com/manufacturers) - [Inventory](https://www.environmental-md.com/inventory) - [Service](https://www.environmental-md.com/service) - Resources Show submenu for Resources - [Drawing Vault](https://www.environmental-md.com/drawing-vault) - [Holding Back the Flood](https://www.environmental-md.com/holding-the-flood-back) - [Pump Monitoring](https://www.environmental-md.com/pump-vibration-and-temperature-monitoring) - [Specifications](https://www.environmental-md.com/specifications) - [Videos](https://www.environmental-md.com/videos) - [Blog](https://www.environmental-md.com/blog) - Info Show submenu for Info - [About](https://www.environmental-md.com/about) - [Connect](https://www.environmental-md.com/connect) - [Quote Request](https://www.environmental-md.com/rfq) - [Training](https://www.environmental-md.com/training) Open main navigation Close main navigation - [Home](https://www.environmental-md.com/) - Products Show submenu for Products - [Manufacturers](https://www.environmental-md.com/manufacturers) - [Inventory](https://www.environmental-md.com/inventory) - [Service](https://www.environmental-md.com/service) - Resources Show submenu for Resources - [Drawing Vault](https://www.environmental-md.com/drawing-vault) - [Holding Back the Flood](https://www.environmental-md.com/holding-the-flood-back) - [Pump Monitoring](https://www.environmental-md.com/pump-vibration-and-temperature-monitoring) - [Specifications](https://www.environmental-md.com/specifications) - [Videos](https://www.environmental-md.com/videos) - [Blog](https://www.environmental-md.com/blog) - Info Show submenu for Info - [About](https://www.environmental-md.com/about) - [Connect](https://www.environmental-md.com/connect) - [Quote Request](https://www.environmental-md.com/rfq) - [Training](https://www.environmental-md.com/training) Mar 18, 2026, 8:21:05 AM # The Check Valve Hasn’t Changed in 50 Years ![Picture of Jacob McGough](https://www.environmental-md.com/hs-fs/hubfs/jake%20image%20-%20color%20and%20white%20back.png?width=50&name=jake%20image%20-%20color%20and%20white%20back.png) [Jacob McGough](https://www.environmental-md.com/blog/author/jacob-mcgough) Share: [Share this page on LinkedIn](http://www.linkedin.com/shareArticle?mini=true&url=https://www.environmental-md.com/blog/the-check-valve-hasnt-changed-in-50-years) [Share this page on Twitter](https://twitter.com/intent/tweet?url=https://www.environmental-md.com/blog/the-check-valve-hasnt-changed-in-50-years) [Share this page on Facebook](http://www.facebook.com/share.php?u=https://www.environmental-md.com/blog/the-check-valve-hasnt-changed-in-50-years) [Share this page via email](mailto:?body=https://www.environmental-md.com/blog/the-check-valve-hasnt-changed-in-50-years) ![Surgebusters (1)](https://www.environmental-md.com/hs-fs/hubfs/Surgebusters%20(1).jpg?width=720&height=405&name=Surgebusters%20(1).jpg) ### The System Around It Has. Walk into almost any municipal pump station built in the last half century and you will likely find the same familiar piece of equipment sitting on the discharge line: the swing check valve. For decades, the conventional swing check valve,  often equipped with a lever and weight, has been the default solution for preventing reverse flow. It’s simple. It’s mechanical. And for many years, it was the best available option. But pump stations, force mains, and distribution systems have evolved dramatically. Flow rates are higher. Transient conditions are better understood. Modeling tools like KY Pipe and AFT Impulse now show us what actually happens when pumps start and stop. And what those tools consistently reveal is this: **Many of the problems engineers blame on pipelines are actually caused by the check valve.** ### The Hidden Problem with Traditional Swing Check Valves A conventional swing check valve operates on a simple concept. A hinged disc swings open when water flows forward and swings closed when the flow reverses. In theory, that sounds ideal. In practice, several hydraulic realities work against it. First, the disc must travel a long arc,  typically **80 to 90 degrees,** before it reaches the closed position. Second, closure only occurs **after reverse flow begins**. That means the disc often slams into the seat as the flow reverses direction, generating the pressure spike engineers know as **water hammer**. The faster the reverse velocity, the harder the slam. Hydraulic testing has shown that conventional cushioned swing check valves can produce surge pressures **six times higher** than modern resilient hinged designs under the same pump shutdown conditions. When that surge propagates through a pipeline system, the results can include: • Pipe movement • Joint separation • Excessive vibration • Premature valve wear • Catastrophic failures In other words, the pipeline didn’t fail. **The valve did.** ### The Industry Quietly Shifted Over the past 15–20 years, many utilities have begun transitioning away from traditional metal-disc swing checks toward **resilient hinged check valve designs**. The concept is straightforward: reduce the number of moving parts, shorten the closing travel, and allow the valve to respond to changing flow conditions faster. One example of this approach is the resilient hinged [**SurgeBuster check valve by Val-Matic**](https://www.valmatic.com/products/check-valves/surgebuster), originally developed to replace poor performing air-cushioned swing checks that struggled with slamming in pump discharge applications. Several design differences stand out immediately.   ### 1. Short Disc Stroke Instead of requiring an 80–90° swing, the resilient hinged disc travels only **35° before closing**. That shorter travel distance dramatically reduces closing time. And in surge control, **milliseconds matter**. If a valve closes before significant reverse velocity develops, the pressure spike is significantly reduced. ### 2. Disc Acceleration Instead of Weights Traditional swing checks often rely on external levers, springs, or weights to speed up closure. Unfortunately, these components introduce new problems. They pull the disc into the flow stream, partially blocking the pipe and increasing head loss. They also introduce bearings, pins, and seals, all of which wear over time. Modern resilient hinged designs solve this differently. Instead of forcing the disc into the flow, one variant use an **internal disc accelerator** that moves with the disc and speeds closure without obstructing the flow path. The result is faster response without the maintenance headaches.   ### 3. Fewer Mechanical Failure Points A conventional swing check may contain: • hinge pins • bushings • shafts • packing seals • external levers • adjustable weights • air cushion cylinders Each one is a potential failure point. A resilient hinged check valve typically operates with **only two moving components:** • the flexible disc • the disc accelerator Less hardware means fewer wear surfaces, and fewer maintenance calls five years down the road. ### Why Surge Matters More Than Ever Today’s pump stations are pushing far more water than systems built in the 1960s and 1970s. Large regional pump stations regularly handle **tens of millions of gallons per day**, sometimes through pipes exceeding 36 to 48 inches in diameter. When a pump stops in systems like these, the flow reversal occurs quickly, often in less than a second. Testing has shown that conventional swing check valves under these conditions can generate downstream surge pressures **around 150 psi above static pressure** during closure. Under the same conditions, resilient hinged designs have produced surge pressures closer to **25 psi above static pressure**. That difference is enormous when multiplied across miles of pipeline. ### The Installation Detail Engineers Often Miss Even the best check valve will perform poorly if it is installed incorrectly. One of the most overlooked details in pump station design is **straight pipe length around the check valve.** The *Pump Station Design Revised 3rd Edition* reference recommends placing check valves **at least four to five pipe diameters downstream of the pump discharge** to reduce turbulence and prevent disc flutter. Additional guidance from MSS SP-92 suggests providing **approximately ten pipe diameters of straight run downstream** before tees, reducers, or fittings, however unclaimed suggestions minimally state the below. ![](https://cdn-images-1.medium.com/max/720/1*tc9tX4zQ-knIjW2mMZJc2A.png) Why does this matter? Because turbulence affects how the disc behaves. If a check valve is installed directly against a reducer, elbow, or pump flange, the flow entering the valve is often highly rotational. That unstable flow can cause: • Disc oscillation • Premature wear • Increased head loss • Delayed closure • Higher surge pressures In other words, the valve may be perfectly designed — but the installation sabotages it. ### Full-Port Flow Matters Too Another advantage of resilient hinged check valves is that they typically maintain a **full-port flow area equal to the pipeline diameter**. This reduces head loss and allows solids to pass without obstruction, a major benefit in wastewater force mains. Traditional swing checks equipped with weights or springs often hold the disc partially in the flow path, effectively reducing the pipe area and increasing turbulence. That extra turbulence translates directly into energy loss and pump inefficiency. ### The Check Valve Is Part of the Surge System Many surge mitigation discussions focus on: • surge tanks • air valves • VFD ramp rates • pressure relief valves But the check valve is often the **first hydraulic device reacting when a pump shuts down**. If that device closes slowly or slams violently, it can trigger the entire transient event that follows. When engineers model these systems today, they increasingly treat the check valve as a **critical surge control component**, not just a backflow prevention device.   ![](https://cdn-images-1.medium.com/max/720/1*8ym_UVImbiKMER-mR9C_tA.jpeg) ### The Takeaway for Engineers The swing check valve worked well enough for decades. But the hydraulic demands placed on modern pump stations have changed. More demand, longer distances, and tighter system tolerances mean that the details of valve closure (milliseconds of disc movement) now matter more than ever. Resilient hinged check valves aren’t just a product upgrade. They represent a shift in thinking. Instead of reacting to reverse flow, they are designed to **prevent it from developing in the first place**. And in high-energy pumping systems, that difference can mean the difference between a quiet shutdown and a surge event that travels miles down the pipeline. To get more information on resilient hinged check valve options, please [contact us](https://www.environmental-md.com/connect).   [infrastructure](https://www.environmental-md.com/blog/tag/infrastructure), [engineering](https://www.environmental-md.com/blog/tag/engineering), [hydraulic engineering](https://www.environmental-md.com/blog/tag/hydraulic-engineering), [civil engineering](https://www.environmental-md.com/blog/tag/civil-engineering), [valve](https://www.environmental-md.com/blog/tag/valve) ## Related posts [![](https://www.environmental-md.com/hs-fs/hubfs/Pipeline%20maintenance%202-2.png?height=200&name=Pipeline%20maintenance%202-2.png)](https://www.environmental-md.com/blog/the-most-dangerous-valve-in-a-wastewater-force-main-that-nobody-talks-about) [Air Valve](https://www.environmental-md.com/blog/tag/air-valve), [wastewater](https://www.environmental-md.com/blog/tag/wastewater), [infrastructure](https://www.environmental-md.com/blog/tag/infrastructure), [pipeline design](https://www.environmental-md.com/blog/tag/pipeline-design), [civil engineering](https://www.environmental-md.com/blog/tag/civil-engineering), [risk management](https://www.environmental-md.com/blog/tag/risk-management) ## [The Most Dangerous Valve in a Wastewater Force Main (That Nobody Talks About)](https://www.environmental-md.com/blog/the-most-dangerous-valve-in-a-wastewater-force-main-that-nobody-talks-about) ![Picture of Jacob McGough](https://www.environmental-md.com/hs-fs/hubfs/jake%20image%20-%20color%20and%20white%20back.png?width=50&name=jake%20image%20-%20color%20and%20white%20back.png) [Jacob McGough](https://www.environmental-md.com/blog/author/jacob-mcgough) Feb 13, 2026, 7:29:59 AM When a wastewater force main fails, the headlines usually blameage,corrosion, orunexpected surge... 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