For twenty-seven years of his near four decades in the peristaltic pumping market, Rick Balek has been working at Watson-Marlow Fluid Technology Solutions to bring new products and innovation to customers with exacting standards. Who better, then, to jump into a discussion on MPT’s podcast, The Efficiency Point, to provide a history lesson on these reliable machines and how his company is meeting market demands into the future. An excerpt of that conversation follows.
MPT: Have there been any new pumping technologies developed recently for the challenges of chemical metering in water and wastewater treatment?
Rick Balek: There sure has. Recently is sort of an ambiguous term, but over the last decade or so, there’s a technology in peristaltic chemical metering pumps. They use what’s called a cartridge head, and that’s very, very different than what is found in traditional peristaltic tubing pumps that have been around for twenty, thirty, or forty years even.
Really, 1996 is when peristaltic tubing pumps came to fruition in the municipal and industrial water and wastewater space, and back then they used what was called a continuous tube—and, to some extent, continuous tubing is still used today. Continuous tubing is a long piece of tube generally found on a spool of many, many feet. An operator might cut a section off and then put the tubing through the pump, hit the peristaltic pump head, and then connect the suction and discharge.
And the nice thing about it being continuous is that, you could actually just shift the section of the tubing while still remaining in the pump head, and when doing that you essentially sort of rebuild the pump. Therefore, a 7- or 8-foot-long piece of tube can easily last a year to two years. But the negative about continuous tubing is this pressure limitation, which is just about 30 psi.
Skip into the early 2000s, now element tubes were created—a piece of tubing of the same material but a much shorter length, where the fittings are generally on the suction discharge side of a short piece of tube, and then that short piece of tube is inserted into the pump head, and then the piping is generally attached via an intermediary external piece of interconnecting tubing. And this is still used today.
The advantage is that it can achieve pressures of 100 psi or more, but one of the disadvantages is that when a tubing failed, there was a chance that some of the chemical being pumped out and exposed to the operator or maintenance person.
MPT: What advancements have been made in safety for chemical pumps?
Rick Balek: This is where over the last decade cartridge heads have really come into focus. And the cartridge head is a style of pump technology where the tubing, the rotor, and so on are sort of built into a single use pump head. And the advantage of that is that you can get into even higher pressures and achieve more accurate flow, but should the tube break or if there is a leak, it stays contained inside the pump head.
Now, there is an optional drain port that can be used to control a leakage path to a safe location, but I’d say 99 percent of the customers out of the tens of thousands that use this cartridge head technology don’t do that. They actually dispose of this relatively small, baseball-sized pump head and then put a new head on. Cartridge heads are sort of the standard now when it comes to peristaltic tubing pumps in municipal and industrial water, wastewater, and chemical metering applications.
Also, as far as safety, certainly the HMI—the human-machine interface—allows for safer use and, from a logic perspective, safer operation, as well as the increased use of chemical metering skids.