Right now we are working on final production mold for 1 1/2" Airpinch valve, prototype 4" pinch valve, and 2" ID duckbill check valve. And there is more in the planning stages.

Contact us for more information.

A couple of times recently people have tried to apply flow coefficient (Cv) to low pressure flow. The flow coefficient is the amount of water that will flow through a device (or length of pipe, etc) in one minute with a one psi pressure drop.


[See the Airpinch website and open the Flow Capacity link on the left side of the opening page to find out more about Cv]


At low pressures, like gravity feed, Cv values are not accurate. In the extreme, if there is only one psi head pressure, then conceptually there will be no flow out of the valve ---- because 1 psi minus a 1 psi pressure drop = zero psi or no flow.

Image from www.rtlyrics.net ---- where they got it I have no idea.

Have you ever watched professional painters and wondered why they are pushing the roller so slowly? Here's Why.

Most wall paints are formulated to reduce in viscosity when they are agitated by rolling or brushing so they will flow out smoothly. But go too fast and they will reduce so much that they splatter.

In engineering and physics circles, they are known as pseudoplastic Non-Newtonian fluids. Other Non-Newtonians can increase in viscosity with agitation. A good example is quick sand, which is fine sand or silt which is saturated with water, perhaps from an underground spring. If you step into quick sand, DO NOT PANIC or the quick sand will become more viscous and it may be almost impossible to escape. Instead go slowly and keep the viscosity more water-like.


Other Non-Newtonians include ketchup, blood, printing inks, some lubricants and many industrial materials. Depending on the material, Non-Newtonians can either increase or decrease in viscosity with agitation.

Richway Airpinch brand pinch valves are ideal for controlling Non-Newtonian fluids because they cause little agitation which prevents changes in viscosity.

This blog is designed to make it easy for Richway staff members to post information that may be of value to Airpinch users and prospective users.

It will include product information, new products, applications, and other things that may be of interest.