Author Archives: Christopher Laing

Rolling Stone’s front man Mick Jagger’s second favorite song verse is “start me up”…”I’ve been running hot”.   Did you also know there are restrictive limits regarding the number of times an induction motor can be started in a given time period? The restrictions are due to (“running hot”) temperatures and for that singular reason it

I don’t have one particular subject for this month’s issue, but instead a gentle reminder of several simple things. Just a list of pesky issues that keep popping up on a regular basis. These are things that should not be popping up. …but in the spirit of the season we’ll just call them stocking stuffers. Pumps

Be very careful on self-primer lift applications because the liquid temperature directly affects its vapor pressure and that… …changes the Net Positive Suction Head Available (NPSHA). Example: Self-Primer – two temperatures… two outcomes: For the example we will use two versions of the otherwise same application. The applications are identical in both versions except the temperature

Here are some brief reminders about NPSHA and NPSHR.   NPSH changes with:   Impeller diameter: For the same flowrate on a given system an impeller of a smaller diameter will have a higher NPSHR. Clearance of impeller and wear rings: As clearances open up on the pump over time the NPSHR will also increase. This effect