Thermal shock breaking ice.

Thermal Shock

Angus EwartTech TalkLeave a Comment

Our blog on “Total Discharge Recirculation” mentioned thermal shock as a destructive force that can damage or destroy pump components.  With how destructive this force can be, I thought it necessary to spend some time expanding upon this subject. Wikipedia explains that thermal shock occurs when a thermal gradient causes different parts of an object to expand by different amounts.  This … Read More

A mine filled with ice and water.

The Challenge of Underground Mine “Dewatering”

Angus EwartMining, PumpsLeave a Comment

In-depth Knowledge on Solving Seal Failure in Dewatering Applications If you are an owner, operator or user of Electric Submersible pumps in Mine Dewatering and currently experience multiple seal failures within one year of start-up and installation… Please read on. Additionally, if you are a fellow professional in the field that wishes to share observations and constructive comments then please … Read More

Water boiling in a pot.

Total Discharge Recirculation

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Gain In-Depth Knowledge on Discharge Recirculation In previous blogs we have defined Cavitation and reviewed Discharge Cavitation.  In this blog I would like to discuss a specific type of discharge recirculation known simply as “Total Discharge Recirculation” or “TDR” for short.  All forms of pump recirculation, as the term denotes, evolve some portion of the liquid not following the desired path.  When referencing … Read More

An impeller blade with serious signs of cavitation.

Defining Discharge Recirculation

Angus EwartTech TalkLeave a Comment

Gain In-Depth Knowledge on Discharge Recirculation In our last blog we discussed cavitation singling out suction cavitation to illustrate the concept. In this blog, as promised, we will discuss discharge recirculation, also sometimes referred to as discharge cavitation.  The term discharge recirculation is often used interchangeably with the term discharge cavitation.  Although these two are clearly related they have a few distinct differences.  … Read More

A rusty impeller blade with signs of cavitation.

Gain In-Depth Knowledge on Cavitation

Angus EwartTech TalkLeave a Comment

What it is and how it works Cavitation is potentially the most destructive force at play within a pumping system, however it is the least understood issue by many pump operators. To quote Sun Tsu from the Art of War, “know thy enemy”. In this blog, we will discuss our enemy cavitation and how it relates to pump cavitation. This article … Read More

Slurry being pumped out at a mine.

Velocity Head

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Gain In-Depth Knowledge on NPSHA In this blog we will discuss Velocity Head as it is the final component left of our 6 part NPSH blogs and the one we have avoided addressing previously. Reference books would describe velocity head as a basic concept of fluid engineering that represents the bulk motion, i.e. the kinetic energy, of the fluid. It can … Read More

Slurry being pumped out into a pond.

How to Prime your slurry pump?

Angus EwartPumpsLeave a Comment

Let’s get into priming your industrial pump Did the POTUS really coin this phrase and what does it mean? Today the President of the United States of America, Donald Trump, put the pump industry into the mainstream by claiming to have coined the phrase “priming the pump”.  In doing so he highlighted one of the basic principles of pumping and … Read More

slurry pumps being used to move slurry around.

NPSHA (Available Inlet Pressure)

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Gain In-Depth Knowledge About Our Pumps & Industry In the last blog of this series we explained why a pump requires a positive inlet pressure and introduced the term NPSHR.  As promised, this blog we will investigate the counterpart of NPSHR, Net Positive Suction Head Available  (NPSHA). The pressure available at the pump inlet is a summary of multiple factors. These factors, all expressed in the same units (normally feet of … Read More

Slurry pumps being used in an industry solution.

Required Inlet Pressure or NPSHR

Angus EwartTech TalkLeave a Comment

Gain In-Depth Knowledge About Our Pumps & Industry In my first blog we argued that pumps don’t suck, they actually rely upon atmospheric pressure to push liquid into the impeller. In my second blog, I explained how atmospheric pressure can be expressed in feet of head.  In this blog we will discuss how pressure, measured in feet of head, may or may not satisfy a … Read More

A image of earth and arrows demonstrating the direction of gravity.

Atmospheric Pressure in Feet of Head

Angus EwartTech TalkLeave a Comment

Gain In-Depth Knowledge About Our Pumps & Industry In last weeks blog we touched briefly on the subject of atmospheric pressure.  I wanted to write today’s blog to ensure you understand exactly what atmospheric pressure is and why it affects you and your pumps. As illustrated below, the weight of the air in a 1 inch square column extending to the edge of outer … Read More