Choosing between a chemical process pump and a pump-drive USB kit comes down to the job you are outfitting. The Durco Flowserve MK3 is built to move chemicals in a process line under pressure, while the Masterflex L/S Digital Process Pump Drive Cinch USB Kit is made for connecting a digital pump drive. They are not competing versions of the same thing, so the useful question is: which flow-control gap are you trying to fill?
Quick Verdict
Pick the Flowserve MK3 when you need a true chemical process pump for demanding flow-control work. Pick the Masterflex USB kit when you already have a compatible L/S digital pump drive and need the USB connection piece. One is a complete pump; the other is a drive-level component.
At a Glance
| Product | Listed Price | Condition | What it is |
|---|---|---|---|
| Durco Flowserve MK3 STD Chemical Process DCI Centrifugal Pump | USD 2,750.00 | New - Open box | 3-inch x 2-inch chemical process pump, Model MK3, 250 PSI @ 100°F, DCI material |
| Masterflex L/S Digital Process Pump Drive Cinch 30-3006-6 Connection USB Kit | USD 89.56 | New | L/S digital process pump drive connection USB kit |
Where Each Product Wins
- Durco Flowserve MK3: high-pressure chemical process duty, industrial flow-control work, and buyers who want a process pump rather than a drive accessory.
- Masterflex L/S Digital Process Pump Drive USB Kit: existing L/S digital drive owners who need a new connection kit at a lower-priced entry point.
Product Notes
Durco Flowserve MK3 STD Chemical Process DCI Centrifugal Pump
The Flowserve MK3 is the process pump of this pair. It is described as a 3-inch by 2-inch DCI centrifugal pump, Model MK3, with a 250 PSI at 100°F rating. That makes it a strong match for chemical transfer and process lines where pressure capability matters. The condition is new open-box surplus from 2018, and the pump cannot be tested and includes only what is shown in the pictures. The money-back-if-DOA detail offers a practical safeguard, but the untested status is the main limitation. This is a serious piece of equipment for a serious installation, not an impulse buy.
Masterflex L/S Digital Process Pump Drive Cinch 30-3006-6 Connection USB Kit
The Masterflex L/S kit is the opposite kind of purchase: a drive connection component rather than a pump. It is new and made in the United States, and the name points to the L/S digital process pump drive family it is meant for. If your setup already uses a Masterflex L/S digital drive, this is the low-cost way to add the USB connection piece. The limitation is scope. This is a connection component for a specific drive family, not a general-purpose chemical pump. Match it to the right L/S digital drive, and it fills a specific flow-control gap without the cost of a full pump.
Final Choice by Use Case
Choose the Durco Flowserve MK3 if you need a chemical process pump with real pressure capability and you can accept a surplus unit that cannot be tested. Choose the Masterflex L/S Digital Process Pump Drive Cinch USB Kit if you have a compatible L/S digital drive and need a new connection kit. The $2,660.44 difference between the two listed prices reflects the real difference between a full process pump and a drive connection component.
