Dual Seal End Pieces

October 15th, 2015 | by | No comments yet

Motivation For years, IMI-Flow Design has provided valves with end connections customized for the job at hand.  When field disconnection is desired this means our carefully designed o-ring unions with their superior o-ring retention, but on system connections for an isolation valve a more permanent and tamper-proof system is required. The dual seal end-piece design is a permanent


Why’s There A Nut Under That Handle?

October 15th, 2015 | by | No comments yet

What? Many products from IMI-Flow Design have an integrated ball valve for isolating the terminal.  Under the handle of these ball valves there’s a nut.  This is called the “packing nut”.   Concealed under the packing nut is… wait for it… packing.  Specifically, there’s a piece of PTFE which is squeezed by the nut to


Three Classes of Flow Controller

May 11th, 2015 | by | 1 comment

Class I These are the simplest flow controllers mechanically.  The differential pressure across the device acts on an area, which tends to move a piston.  This force is opposed by a force which varies with position (normally a spring).  The force due to pressure and the spring force determine the position of the piston.  The


Venturi Balancing Valves

December 31st, 2014 | by | 1 comment

IMI Flow Design sells manual balancing valves based on a fixed venturi element.  This brings up certain questions, of course. What’s a Venturi? A venturi, at least in this context, is a device which converts pressure to kinetic energy, then converts it back. To put it simply, it gets narrow, then widens out gradually so


Modulating Control Valves and Autoflow™

December 31st, 2014 | by | No comments yet

The question comes up regularly: does Autoflow™ interfere with the operation of a modulating control valve? After all, as the control valve closes, the Autoflow will be opening. In short, of course it will make a difference, but it will not be worse than without the Autoflow™. Saturation The rate of heat flux from the


Traction Control

December 31st, 2014 | by | No comments yet

Picture yourself on a soggy dirt road. For some reason you’ve stopped and want to get going again. Unfortunately, when you press the gas, one wheel spins. Pressing the gas more just makes it spin more and the car goes nowhere. Then you suddenly remember your car has traction control and activate it. The system


Equalizer

December 31st, 2014 | by | No comments yet

What Is It For? Sometimes a circuit is meant to have variable flow, and it’s important to be sure it’s not disturbed by changes in flow from other circuits.  This can be accomplished by being sure the circuit always has the right in pressure difference between its supply and return (differential pressure or DP). In