Choosing between these two listings is less about picking a winner and more about matching the tool to the job. One is an industrial chemical-process centrifugal pump with a 1.5-by-1-inch footprint and a four-figure price. The other is a compact L/S digital process pump drive connection USB kit at $89.56. Both fall under industrial pumps flow control, but they answer very different questions.
Quick verdict
Pick the Flowserve MK3 when you need an actual process pump, rated at 275 PSI @ 100°F, to move chemical flows through a line. Pick the Masterflex L/S kit when you need a connection component for an L/S digital process pump drive and want to stay at $89.56. The price spread is roughly $3,660, and that gap reflects scope and physical scale: one unit is a complete industrial pump, the other is a drive connection kit.
At a glance
| Item | Flowserve MK3 Chemical Process Pump | Masterflex L/S Digital Process Pump Drive Connection USB Kit |
|---|---|---|
| Price | $3,750.00 | $89.56 |
| Type | 1.5" x 1" centrifugal chemical process pump | Digital process pump drive connection USB kit |
| Condition | New/open box | New |
| Notable specs | 275 PSI @ 100°F, 200 lb, D4 material | USB kit for L/S digital process pump drive |
Where each product wins
Flowserve MK3 wins for:
- Actual pump duty with high pressure and a full-size process pump format.
- Chemical-process construction with a D4 material code.
- 1.5" x 1" size and 275 PSI @ 100°F rating.
Masterflex L/S wins for:
- Keeping the purchase price at $89.56.
- Fitting into an existing L/S digital pump drive setup.
- Not being a 200-lb process pump; the physical scope is limited to the kit components.
Product notes
Flowserve MK3 STD Chemical Process D4 Centrifugal Pump
For a process line that needs a dedicated centrifugal pump, this is the unit to build around. The 1.5" x 1" MK3 STD carries a 275 PSI @ 100°F rating, uses a D4 material code, and weighs about 200 lb. That scale and pressure capacity justify the $3,750 price if you are actually piping liquid through a chemical process. The trade-off is that this is surplus/new-open-box inventory with no way to test it before purchase, and the buyer has to handle freight logistics for something that heavy. It is the only listing here that can serve as the core of a full process move.
Masterflex L/S Digital Process Pump Drive Cinch 30-3006-6 Connection USB Kit
At $89.56, this listing costs less than the Flowserve unit, and it is a different kind of component. The Masterflex L/S kit is a USB connection kit for a digital process pump drive, designed for L/S drive hardware. That makes it a practical link if you already have the matching drive and need the connection capability. It is not a standalone pump, so the limitation is scope: you need the L/S drive to go with it before any fluid can move. For a narrowly defined component purchase, the $89.56 price is the main reason to choose it.
Final choice by use case
If your project needs a complete chemical-process centrifugal pump with the physical capacity to move fluid through a line, the Flowserve MK3 is the clear pick. If your project only needs a USB connection kit for an L/S digital process pump drive, the Masterflex is the right buy at $89.56. Decide by the hardware you already have and the flow you actually need to create.
