In today’s post, we’re going to take a look at two of the most common sanitary centrifugal pumps- the C Series and Waukesha’s 200 Series pumps. While they’re both sanitary centrifugal pumps, designed to moved high volumes of low viscosity products, there are a number of features and benefits to each that end users and engineers should be aware of before specifying a one pump or the other. So what’s the difference between a C Series and a 200 series? Let’s dig a little deeper.
Industry Standard vs. Proprietary Design
Let’s start by clearing something up- almost all C series pumps are the same. The C series was originally developed by Tri Clover as one of the very first sanitary centrifugal pumps. Over the years, most pump manufacturers in the sanitary space began to offer their own C series pump- manufacturers including Waukesha, Ampco, Topline, Q Pump, Dixon, and probably a few others whose names presently escape me. While each manufacturer will almost certainly claim their C series is better than the competitors, parts for the core C Series models (C114, C216, and C328) are volumetrically identical and largely interchangeable.
The 200 series, on the other hand, is a proprietary design by Waukesha Cherry Burrell and is manufactured and assembled in Delevan, WI. There are no other manufacturers of either the 200 or pharmaceutical S200 series. The 200 series builds on the rich legacy of the C series and brings new features like a truly closed coupled design, sealed, semi-open impeller for greater efficiency and cleanability, as well as simplified seal design, optional bearing power frame for heavy duty applications, and more documentation options for higher purity processes.
Open vs. Semi-Open Impeller
Now that we’ve given a high-level overview of the pumps- let’s talk turkey and get into some of the technical differences between the C Series and 200 Series pumps.
Every centrifugal pump has two critical parts- an impeller and a volute or casing. Obviously, both the 200 series and C series have these, but there is a considerable design difference between the two impellers.
The C series features a fully open impeller with a 0.060” clearance between the impeller and the back plate. The 200 series features a semi-open impeller and 0.030” clearance between the impeller and the back plate. This tighter tolerance and impeller design make the 200 series more efficient and draw less power than a C series at a comparable duty point. The drawback is cost, ease of maintenance (the 200 series requires shimming while the C series requires simple stub shaft adjustment), and to some extent, cleanability.
JM vs. C Face Frame
Next, let’s talk about motors and how the pump actually attaches to the motor shaft. With the C series, we use the very common NEMA C Face motor frame to mount our adapter and stub shaft. After setting our clearances, we assemble the C face impeller onto the stub shaft for close coupled mounting.
With the 200 series, we’re actually going to use the less common NEMA JM frame style motor. JM frame motors are very similar dimensionally to C framed motors but feature an extended shaft specifically for centrifugal pump impeller mounting. That means that instead of mounting the impeller to a stub shaft like we do with a C series or W+ series, we mount the impeller directly motor shaft.
One Seal vs. Many
This one probably isn’t quite what you’re thinking. Both the C series and the 200 series offer a number of different types of seals. We’ve done a whole post on C series seal options (check it out here) and the 200 series features a “Type-1” and “Type-4” seal, as well as optional cartridge and aseptic seals.
What we mean by “one seal” is actually one set vs. many sets of seal components. For the C series, the C100, C114, C216, and C328 are all going to have different seal component part numbers. Said another way, you can’t use a C100 rotating seal with a C114 pump.
With the 200 series, the 2045, 2065LV, 2065, 2065HV, 2075, 2085LV, 2085, and 2105 all take the exact same seal components. The only items that are model specific are the impeller o-ring and the casing o-ring. This greatly simplifies stocking replacement parts when you have a facility full of sanitary centrifugal pumps.
S200 Series Pharmaceutical Pumps
The last distinguishing feature we wanted to touch on between the 200 series and C series are some additional features and options specifically for high purity and pharmaceutical applications. With the C series, we have relatively few options for documentation- pretty much just MTRs.
With the 200 series, we have additional product features and documentation options, including USP Class VI elastomers, MTRs, casing drain options, upgrade surface finishes (including electropolish), surface finish certs, Ra Mapping, and even a Gauss certificate.
Further, there is even an additional series of 200 series pumps, the S200 series, designed specifically for pharmaceutical applications. While the 200 series and S200 series look and perform almost identically, standard features of the S200 series include all machined, low ferrite components and standard 20 Ra surface finishes. Material heat numbers are available on all product contact components, greatly reducing validation time.
That wraps up our comparison of the 200 series and the C series. So which one is best for your application? Like most things in the high purity space, it depends. If you’re looking for a quick, low cost, easy to maintain sanitary centrifugal pump, the C series has been around for over 50 years and you can’t go wrong. If you’re looking for a workhorse pump that is going to run non-stop across the facility, consider the more efficient 200 series. And as always, if you have any questions about which sanitary centrifugal pump is best for your application, contact a Triplex Sales Engineer today!
