Equipment selection · what fourth year leaves out

The pump you sized does not exist

Reflux on the left, Aspen Plus on the right: a two-stage condensate stabiliser built and run from one sentence. Unedited except for the waiting.

You calculate the head and the flow, size the ideal pump, write down its efficiency and move on. Every fourth-year project ends there. No plant has ever bought that pump, because it is not for sale, and nobody tends to mention it until your first job.

Join the trial waitlist

Reflux drives the simulation software you already use from plain English, and it is being built to size from what is actually for sale rather than from an ideal machine. Whatever simulator you use, we’ll build for it. The one-pager is below the form.

Which software you use

Select all that apply. This is what decides the build order.

What you work on optional

Select all that apply.

01

What the textbook does

Calculate the head and the flow, size an ideal pump, write down its efficiency. Every fourth-year project ends here, and the number you write down is a number no supplier has ever quoted.

02

What the plant does

Somebody opens a manufacturer’s catalogue and looks for a curve that covers your operating point with margin. It is slightly wrong in every direction, and you either accept that or you pay for a custom unit that costs more and arrives later. The drawing below is the whole argument: your duty point sits in the gap between the curves that exist.

03

The wall

The price is rarely on the page. You email for a quote, you wait, and you design around whatever number comes back. Pumps are the easy case: the same is true of vessels, valves, heaters and compressors.

HEAD FLOW 78% A B C MARGIN IDEAL
Three vendor curves, an efficiency island and a system curve. The duty point sits in the gap: the nearest curve covers it only once you accept the margin box around it.

Sizing from what exists, then simulating with it

The simulator lets you type in an ideal machine and does not ship with a live catalogue of what is actually for sale. Closing that gap — size from what exists, then simulate with it — is one of the things we are building.

We’re opening a small trial to people who ask for it, and we are not precious about which software you run. Whatever you use, we’ll build for it.

Nathan Ruberto · Co‑Founder, CEO

Back to reflux.sh ->