Cost & Quoting

Costing and Quoting Pump and Compressor Assembly Work

What actually drives cost per assembled pump or compressor, how to build a quote that holds, and the hidden lines that sink margins.

A defensible per-unit quote for rotating equipment stacks five cost pools: purchased material, assembly labor, test and run-in, rework reserve, and allocated overhead plus warranty. On a mid-size centrifugal pump, purchased parts (castings, seals, bearings, motor) often run 55 to 70 percent of factory cost, so a bad bill-of-material price swamps every efficiency you gain on the floor. Start every quote from a costed BOM, then layer conversion cost on top. The Unit Assembly Cost calculator lets you assemble these pools into one auditable per-unit number instead of a single loaded rate.

Assembly labor is takt time times a fully burdened rate, not a base wage. If takt is 10.0 min and a build touches four stations for 34 min of total hands-on time, that is 0.567 labor-hours. At a burdened rate of 58 dollars per hour (wages, benefits, payroll tax, and idle time rolled in) direct assembly labor is 32.90 dollars per unit. Estimators who quote off the 28 dollar base wage understate labor by roughly 52 percent. Include line imbalance: if the slowest station runs 15 percent over takt, add that idle-wait cost to every station upstream.

Test and run-in are separate cost lines and often the throughput constraint. A performance test stand tied up 17 min per unit at a 140 dollar per hour stand rate adds 39.70 dollars before any energy. Run-in energy is real money on motored equipment: a 30 kW unit run for 45 min draws 22.5 kWh, and at 0.14 dollars per kWh that is 3.15 dollars, plus demand charges if several stands ramp together. The Run-In Energy Cost calculator turns motor power, run duration, and tariff into a per-unit figure you can defend in a quote review.

Rework is the line that quietly destroys margin, because it is nonlinear. A seal reseat that scraps 40 min of labor plus a 22 dollar seal kit costs roughly 60 dollars per event. At a 6 percent first-pass rework rate across 45 units per shift, that is 2.7 events, about 162 dollars per shift, or 3.60 dollars spread over every good unit. Drive the rate to a world-class 1.5 percent and that line drops to 0.90 dollars. The Rework Cost calculator lets you model rate, labor minutes, and scrapped-part cost so the reserve in your quote matches reality.

Warranty exposure belongs in the quote as a reserve, not a surprise. If field return rate on a product line is 2.2 percent and the average claim (parts, labor, freight, and diagnosis) is 640 dollars, expected warranty cost is 0.022 × 640 = 14.08 dollars per unit shipped. Underpricing this line is how a program that looks 8 percent profitable at the quote turns into a loss after 18 months of returns. The Warranty Exposure calculator converts return rate and claim cost into a per-unit reserve you can carry as a known liability.

Overhead allocation decides whether your quote is competitive or fantasy. Spread fixed cost (facility, supervision, quality lab, calibration) over actual throughput, not capacity. A cell carrying 42,000 dollars per month of fixed cost at 900 units per month allocates 46.70 dollars per unit; at 650 units the same fixed cost becomes 64.60 dollars, a 38 percent swing driven purely by volume. Quote off a realistic volume commitment and state it, because a low per-unit overhead assumption that never materializes is the single most common estimating miss.

Test-stand capacity feeds cost even when it is not a direct line. If demand outruns stand capacity (say 45 units needed against 26 the stands can clear), you either add a stand, add overtime, or subcontract, and each carries a different per-unit penalty. Model this with the Test Stand Capacity and Assembly Takt calculators before pricing, because a quote that ignores the bottleneck understates cost the moment volume ramps. A second stand at 180,000 dollars amortized over 24 months and 900 units adds 8.33 dollars per unit.

Assemble the quote and pressure-test it. Sum material (say 480 dollars), direct labor (32.90), test and run-in (42.85), rework reserve (3.60), warranty reserve (14.08), and allocated overhead (46.70) for a factory cost near 620 dollars, then apply margin. Where estimates go wrong is predictable: base wage instead of burdened rate, overhead spread on capacity not volume, and rework and warranty left at zero. Carry each as an explicit line so a customer or auditor can see the build-up, and revisit the reserves quarterly against actual return and rework data.

Published 2026-07-01.