Category: check valves

CVNUCB, CVNHPN, CVNMCB and JCV Series Check Valves Product Spotlight

Check ValvesProduct Spotlights June 1, 2020

Some versatile, miniature spring-loaded nylon check valves

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

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What is Cracking Pressure?

Check ValvesMiniature Valves May 24, 2019

Why check valve cracking pressure is such a critical specification

What is check valve cracking pressure? Cracking pressure is the minimum upstream pressure required to open a check valve enough to allow detectable flow. Detectable flow is when the check valve allows a small but steady flow of liquid or gas to pass through the valve body and out through its outlet port.

A check valve’s cracking pressure is a technical specification and is usually provided as psi or psig (pounds per square inch or pounds per square inch gauge) or bar (the metric equivalent of psi and psig) or ...

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Stainless Steel Materials for Miniature Flow Control Valves

Check ValvesMaterials Miniature Valves November 29, 2018

Why stainless steel?

Stainless steel is a steel and so it is typically very strong. This gives it great pressure and temperature resistance. It is also a tougher, more durable metal than cast iron, ductile iron, brass or copper.

Stainless steels get their name from the fact that they are very corrosion resistant. This plus toughness and strength make them a preferred  ...

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Five Tips for Selecting the Right Valve

Check ValvesMiniature Valves August 1, 2018

Choose the right valve means answering key questions first

Knowing what makes a valve the right choice

Valves control gas and liquid flow in almost every process and system. As common as they are, choosing the right valve can sometimes be time consuming and confusing.

Begin valve selection by first gathering some basic information on system performance requirements. Knowing this will make it easier to find the right valve. The five tips in this article focus on how to match valve features with these requirements...

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NRV and NVRT Series In-line Air and Gas Pressure Relief Valves

Check ValvesMiniature ValvesProduct Spotlights February 28, 2018

New from ISM Design - Pressure relief valves for in-line flow and low clearance areas

NRV and NVRT plastic air and gas pressure relief valves
The featured new products in this post are the NRV nylon relief valves and NVRT in-line relief valves. They are designed for pressure relief venting of gases, gas mixtures or vapors that do not represent health or safety risks and are not reactive under normal atmospheric conditions*.

NRV and NVRT pressure check valve performance ...

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CVSF Series Valved Suction Strainers – New Products

Check ValvesMiniature ValvesProduct Spotlights August 15, 2017

One-way foot valves with built-in 40 mesh strainers prevent coarse particle contamination

About the CVSF valved suction strainer
Our featured new product is the CVSF series of valved suction strainers, also called suction filters or foot valves. The design of these valved strainers is a spring loaded ball check valve combined with a 40 mesh stainless steel domed strainer.

The CVSF series strainers come in Kynar, Nylon, polypropylene and ...

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Diaphragm Check Valve Featured Products A1172 and A1173

Check ValvesProduct Spotlights February 16, 2017

These low pressure plastic diaphragm check valves are durable and economical

About the featured miniature diaphragm check valves
Our featured check valves are the compact A1172 (blue) and A1173 (black) plastic diaphragm check valves. They are designed for vacuum and low-pressure systems and only need very low pressure differences to open or close.

The valve bodies are made of quality heat stabilized Nylon ...

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New Overstock Plastic Diaphragm Check Valves

Check ValvesProduct Spotlights January 26, 2017

ISM has just added a selection of diaphragm check valves to our overstock parts

A little about our overstock plastic diaphragm check valves
We are known for our broad selection of low-pressure and vacuum system component parts. One of our most frequently requested fittings is the diaphragm check valve. This type of check valve is so useful because it provides ...

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How Do Diaphragm Check Valves Work?

Check Valves January 25, 2017

Small-bore low-pressure plastic diaphragm check valves are application workhorses

An introduction to diaphragm check valves and how they work
Check valves come in a wide range of sizes and materials. They provide automatic flow control of liquids and gases using a variety of mechanisms. Small-bore low-pressure systems and vacuum systems make extensive use of diaphragm check valves. They are used to prevent reverse flow and the problems that could result from it. This post briefly describes how most ...

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Spring Loaded Check Valves – Check Valves Part III

Check Valves October 28, 2015

Spring loaded check valves are also commonly used

The first post in this series described check valves as valves that allow liquid or gas flow in only one direction. Like plastic diaphragm check valves, spring loaded check valves prevent reverse flow. Miniature in-line spring loaded check valves have particular qualities that make them appropriate in some air, gas and fluid flow control applications. In this post, I will review some basics of ...

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Plastic Diaphragm Check Valves – Check Valves Part II

Check Valves September 9, 2015

Plastic diaphragm check valves are widely used

In my previous post about check valves, I provided a brief overview of check valves. Continuing on that subject, what I want to talk about next is a very pragmatic type of check valve used for miniature pneumatic and fluidics flow control – the plastic diaphragm check valve. Diaphragm check valves are widely used because they are effective and economical. They are also considered to be highly adaptable because of their design characteristics. In this post, I will provide a broad outline of ...

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Checking Out Check Valves – An Introduction

Check Valves July 28, 2015

Check valves are mostly invisible in everyday applications but are critical for flow control

Introduction
Check 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 they are widely used for everyday applications, the how and why of check valve operation is not always ...

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