Positive Displacement Pumps – what they are & how they differ from centrifugal pumps

positive displacement pump book

Course book from Amazon

More engineering training people, this time on positive displacement pumps. There are basically two types of pumps, centrifugal and positive displacement.

In one of the first posts to the site, we began with centrifugal pumps and some of their characteristics. This post will deal with the other half of those pump classes – positive displacement.

It’s important that you know the differences between the two classes, mainly because the type of pump you choose, or that should be installed on that system, will be dictated by the fluid being pumped and the purpose of the system.

A building or stationary engineer should be able to look at a pump and be able to give out at least some rough classification characteristics like if it’s a positive displacement type or centrifugal. You should also be able to determine what type of pump SHOULD BE installed based upon the system and purpose. How do you tell? No idea, but the information below just may help. Read more

Replacing a Mechanical Seal on a Pump

The awful condensate pumps - both have bad mechanical seals.

The awful condensate pumps – both have bad mechanical seals.

Let me re-phrase, attempting to replace a mechanical seal on a pump.  I was all jazzed up Saturday night.  I had an itch.  This itch could only be solved by having more cowbell.  Nah, I had an urge to do some work.  If you saw that recent post about the relief valve without a piped drain, in one of the pictures you maybe saw a set of blue pumps.

Before you get on me, I have done seals before.  This one was stubborn and the pump was critical.  It had to go back together unrepaired hence the attempting part. Read more

Pumps – Basic Principles of Operation

principles of pump operation

Insides of a pump – gross!

This post on the basic principles of pump operation will be quick.  Before getting too deep into the different types of pumps, and things like where we might see the pumps in buildings, let’s discuss the basic engineering principles behind the operation of a pump.

As we learned about in the earlier pump post on like what they are, they are a device that uses an external power source to apply force to a fluid in order to move the fluid.

A shaft, or long metal cylindrical pole, with a motor on one end that can turn the shaft and a head or device (impeller) that move the fluid. Read more

Pumps – what they are, classifications, components


Sweet lookin’ fire pump

Excellent.  The end of 2013, the first training I have decided to put up is going to be about pumps.  For this module, we are going to take at quick look at pumps.  The actual engineering definition, the different classifications and why they may be chosen that way, and maybe some other garbage about them.  Eventually, the next pump training section will be up and we will go from there.  Cool? Read more