CVNUCB, CVNHPN, CVNMCB and JCV Series Check Valves Product Spotlight (2024)

Some versatile, miniature spring-loaded nylon check valves

A product overview of some of ISM’s popular product seriesThese compact made-to-order spring-loaded check valves come in a versatile range of connection types, cracking pressures and O-ring seal material choices. They are made of tough nylon plastic with stainless steel springs.

These USA-made check valves provide economical and reliable check valve options without sacrificing quality or durability.

Watch this short video overview about these spring loaded check valves >>

Compact, spring-loaded (spring assist) plastic check valves are useful for a wide variety of applications. Their small size, low weight, durability and broad chemical compatibility makes them versatile choices for small-bore applications requiring air, gas and liquid backflow protection.

Nylon body materialNylon provides good durability and chemical resistance along with low permeability to gases. It also performs well at elevated temperatures. Nylon is strong, resilient and resists abrasion, crushing and cracking.

Stainless steel springsThese check valves use 303 stainless steel springs. 303 stainless steel is a good general-purpose stainless steel that is tough as well as corrosion and heat resistant.

Compact check valves with choices of connection type and flow direction

• Hose barb by hose barb (choose uniform or reducing flow)
• Male NPT pipe thread by hose barb (choose flow in either direction)
• Male NPT pipe thread by male NPT thread (choose uniform or reducing flow)
• Compression style by male NPT pipe thread (choose flow in either direction)
  

Compact check valves with a choice of O-ring seal materials

• EPDM is a durable, versatile rubber with excellent chemical and heat resistance.
• Viton® (FKM) rubber is durable and resistant to a wide variety of chemicals and fluids, even at high temperatures.
• Buna-N (nitrile, NBR) rubber is durable and has excellent resistance to petroleum oils and fuels, silicone greases and oils, ethylene glycol fluids and water.
  

Get more information about elastomers and rubbers, what they are plus information about their chemical compatibility and corrosion resistance >>

Compact check valves with a choice of cracking pressures

• 1/2 psi (3.4 kPa)
• 1 psi (6.9 kPa)
• 3 psi (20.7 kPa)
• 6 psi (41.4 kPa)
• 10 psi (68.9 kPa)

Find out more about cracking pressure and the challenges of choosing cracking pressures for low-pressure applications>>

An important installation note
Check valves need to be oriented correctly to function properly. Flow direction for the CVNUCB, CVNHPN, CVNMCB and JCV series check valves is from the end described as the inlet or inlet port and on out through the outlet or outlet port.

CVNHPN Series Nylon Nipple Check Valves >>

• Made to order
• Natural nylon bodies
• Cracking pressure options: 1/2, 1, 3, 6 and 10 psi
• Uniform or reducing (larger-size to a smaller-size) flow
• Buna-N (nitrile), EPDM and Viton® (FKM) O-ring seal options
• 1/8", 1/4", 3/8”, 3/4", 1/2" and 3/4" male NPT pipe thread size options
  

CVNMCB Series Nylon Check Valve Adapters >>

• Made to order
• Natural nylon bodies
• Cracking pressure options: 1/2, 1, 3, 6 and 10 psi
• Choose flow from barb to thread or from thread to barb
• 1/8", 1/4”, 3/8”, 1/2", 3/4" and 1" male NPT pipe thread sizes
• 3/16", 1/4", 5/16”, 3/8”, 1/2", 5/8”, 3/4" and 1" hose barb sizes
• Buna-N (nitrile), EPDM and Viton® (FKM) O-ring seal options
  

CVNUCB Series Barbed Nylon Check Valves >>

• Made to order
• Natural nylon bodies
• Cracking pressure options: 1/2, 1, 3, 6 and 10 psi
• Uniform or reducing (larger-size to a smaller-size) flow
• 1/8", 1/4", 5/16”, 3/8”, 1/2", 5/8” and 3/4" hose barb sizes
• Buna-N (nitrile), EPDM and Viton® (FKM) O-ring seal options

What does precision molded mean?The CVNMCB and CVNUCB check valves have hose barb connections that are precision molded. This means the hose barbs on these fittings are made using proprietary technology that eliminates parting lines on the hose barb sealing surfaces. No parting lines on the barbs means there is no potential flash or mismatch. No potential flash or mismatch means there are no potential leak paths on the barbs. The sealing surfaces of these hose barbs are entirely seamless.

Get some insight into hose barb design and how this can affect your application >>

Hose barb critical sealing surfaces

• the barb slopes
• the barb shafts
• the barb ridges or gripping edges

Hose barb connections with no potential leak paths between the sealing surfaces of the hose barb and the flexible plastic tubing provide the best leak-proof seals.

JCV Series Compression by Male NPT Nylon Check Valves >>

• Made to order
• Natural nylon bodies
• 1/4", 3/8” and 1/2" male NPT pipe thread sizes
• Cracking pressure options: 1/2, 1, 3, 6 and 10 psi
• 1/4", 5/16”, 3/8”, 1/2", 5/8” and 3/4" compression sizes
• Compression-to-threaded or threaded-to-compression flow
• Buna-N (nitrile), EPDM and Viton® (FKM) O-ring seal options

Some basic information about compression style connectionsCompression style connections are quick and easy to install, disassemble and reassemble. These connections provide tight, sure, leakproof seals without the use of clamps. They are especially useful for higher pressure applications that are not suitable for hose barb connections.

Compression fittings are most commonly used with harder tubing. This is because the plastic tubing needs to be stiff enough to hold up to the compressive force between the nut and the ferrule of compression style connections.

Recommended plastic tubing includes PEEK, nylon, Teflon® (PTFE), Kynar® (PVDF) and polyethylene. It may be possible to use softer tubing with compression style connections if the tubing walls are reinforced using tubing inserts. Inserts support the tubing wall so that it doesn't collapse under compression.

J series tubing inserts from ISM >>

Get tips and insights about check valves and how they workCheck valves, non-return or one-way valves, allow liquid or air to flow in only one direction. Manufacturers make them in a wide range of sizes and types. Tremendous varieties of applications use them to prevent costly or even dangerous backflow.

Even though check valves are widely used for everyday applications, the how and why of check valves and their different designs is not always well understood. Here is some additional information about check valves from the ISM blog:

• Spring Loaded Check Valves – Check Valves Part III >>
  A brief review of the features, uses and characteristics of miniature spring-loaded check valves in air, gas and liquid flow control applications.
  
• Checking Out Check Valves – An Introduction >>
  How miniature check valves work and function plus descriptions of the most common types. These valves allow liquid or air to flow in only one direction.
  
• What is Cracking Pressure? >>
  Get a better understanding of this critical check valve specification plus advice about selecting check valves. This includes details about how check valve cracking pressure affects reseal pressure and performance. This post also contains information about how check valve selection and sizing can help prevent premature wear.
  
• More blog articles about check valves >>
  

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Some other, related blog posts

• In-line Filters for Miniature Flow Control Component Protection >>
  How pairing miniature in-line filters with precision orifices and check valves in flow control systems can boost performance and help improve reliability.
  
• Five Tips for Selecting the Right Valve >>
  Learn some useful tips for selecting the correct type of valve for your application. Choosing the right valve begins with knowing the role it plays. Knowing its purpose plus a few more key considerations will simplify and speed up any valve selection process. These valve selection tips are a great place to start.
  
• Plastic Diaphragm Check Valves – Check ValvesPart II >>
  Diaphragm check valves are widely used because they are effective, reliable and economical.
  
• How Do Diaphragm Check Valves Work? >>
  Many small-bore low-pressure systems use plastic diaphragm check valves. This post describes how the two major types of low-pressure miniature and small-bore diaphragm check valves work.
  

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Are you developing a design for or maintaining a low-pressure (less than 125 psi, 8.6 bar) small-bore air, gas or fluid system? Then ISM has the valve for it.

Get a catalog and find out more about the miniature flow control and fluid management valves we carry >>

The ISM Miniature Flow Control Valves catalog includes

• Product specifications
• Photos and rendered CAD images of the valves
• Links to product pages in our e-commerce catalog

Check out our complete lineup of miniature flow control valves >>

Keep in mind we carry thousands of miniature flow control valves. Plus, thousands of related products like connectors, adapters, gauges and so on.

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Learn more about the different types of miniature flow control valves you can get from us >>

Diaphragm Check Valves | Spring Loaded Check Valves | Duckbill Check Valves | Plastic Push-In Check Valves | Ball Check Valves | Piston Check Valves | Poppet Check Valves | Modular Check Valves | Plastic Ball Valves | Brass Ball Valves | Stainless Steel Ball Valves | Needle Valves | Metering Valves (Needle) | Metering Valves (Flow Control) | Button-Pilot-Shuttle-Toggle Valves | Stopco*cks | | Regulators | Pinch Valves

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