September 2017 - Issue 196
e-news for Flow Control Solutions



D2P Marlborough
Marlborough, MA
September 27 & 28
Royal Plaza Trade Center
Booth #237
More Info
How does a check valve work?

Smart Products Catalog PDF

O-rings aren't perfect, but what is?
O-rings provide an internal (and sometimes additional external) seal for our check / pressure relief valves. To the naked eye, they appear perfectly smooth. However, by nature, they often have tiny imperfections that can, over time, allow flow to escape. Thus, o-rings aren’t perfect, but again what is? Pictured below is a Model #122 valve; zoomed in, you can see the external o-ring’s imperfections.


At Smart Products, we have worked with o-rings for over 30 years and our expert knowledge allows us to have some control over them by:
  • washing o-rings twice to remove any debris 
  • curing o-rings to affect their properties via various methods (i.e. sulfur, peroxide, etc.) 
  • prescribing a soak test (if needed) to determine chemical compatibility 
  • selecting o-ring materials and durometer (hardness of rubber), as well as spring force to be an ideal match for a specific design criteria 
All of these solutions are available to customers, upon request. We offer o-rings in 7+ materials to include: Buna-N, Ethylene-Propylene, Viton®, Silicone, Fluorosilicone, Aflas, and Kalrez®. A Product & Application Specialist can assist customers in selecting the right o-ring option for a specific design criteria. When building your custom valve, be sure to share all liquids/gasses coming into contact with the valve, application environment, pressure requirements, and intended shelf life. 

Learn more at these helpful links: O-rings, Check Valve Operation.

For questions or to get started, contact us at (800) 338-0404 or

To view a PDF of our entire product catalog, click here.

Series 300 Modular Check Valves FAQs


Common questions from customers about our most popular valve series:

Q: Are the 300series check valves a quick disconnecting design?

A: The 300 series valves are not a quick disconnecting design and are not designed to be taken apart. The valves are modular, which allows for application versatility. End fittings can be mixed and matched as per customer needs and design. 

Q: For applications that require high heat or vibration, what keeps the end fitting from becoming disconnected?

A: We use special tooling during manufacturing and we offer a hot
melt option, upon request, to bond the end fittings together.

Q: The #315 is described as a Foot/Filtering end fitting, is there a filter in the #315?

A: There is no internal filter present in the 315. However, the design of the fitting allows for air or liquid to vent to atmosphere, while preventing larger debris from entering by way of the vent portion of the fitting.

Q: My application has two different tubing sizes that I need to connect, am I able to do that with the 300 series?

A: Absolutely. The 300 series is a modular valve, which gives us the ability to design it with two different end fittings to meet your project requirements.

Additional questions about Series 300 Modular Check Valves? Contact us at (800) 338-0404 or