Industrial Process Piping Contractor in St. Louis, MO
Process lines have to hold up to real production loads. Legacy Plumbing fabricates and installs process piping for manufacturing, laboratory, and food-grade facilities across the St. Louis industrial corridor.
Request a Process Piping Bid
Tell us scope, schedule, and site address. We reply within one business day.
Process Systems We Install
Shop fabrication plus field installation, with the weld documentation and testing your QA process expects.
Compressed Air & Vacuum
Plant air headers, drops, dryers, receivers, and vacuum systems in aluminum, copper, and stainless.
Process Water & Cooling
Chilled water, process cooling loops, RO/DI distribution, and heat-exchanger tie-ins with proper isolation and balancing.
Chemical & Waste Lines
PVDF, polypro, CPVC, and lined systems for corrosive process and acid waste with neutralization tanks.
Steam & Condensate
Steam mains, traps, condensate return, and PRV stations installed with correct slope, drip legs, and expansion.
Stainless & Sanitary Piping
Orbital and TIG-welded stainless for food, beverage, and pharma applications with passivation and documentation.
Equipment Hookups & Shutdowns
Machine tie-ins, skid connections, and planned shutdown work scheduled around production windows.
How We Run a Process Piping Project
Walk the Plant
We survey existing headers, tie-in points, and access before pricing so the bid reflects the real conditions.
Fabricate Off-Site
Spools built in the shop to shorten field time and shrink your production shutdown window.
Install & Test
Field welds, hydrostatic or pneumatic testing, and system flush with results documented for QA.
Start-Up & Service
Commissioning support plus scheduled service from 7am–3:30pm daily when a line down means a shift down.
Process Piping FAQ
What materials do your pipefitters work in?
Stainless steel, carbon steel, copper, aluminum, CPVC, polypro, and PVDF — welded, brazed, threaded, grooved, and press-fit depending on the service and spec.
Can you work during a plant shutdown?
Yes. We prefabricate as much as possible in the shop and staff extra crews so the in-plant portion fits inside your scheduled shutdown.
Do you provide weld documentation?
Yes. Welder qualifications, weld maps, and test records are delivered as part of the turnover package.
Process Piping Across the St. Louis Metro
The St. Louis industrial corridor — the Earth City and Hazelwood logistics belt, manufacturing in Fenton and Maryland Heights, and the river plants in South City — runs on process piping that can't fail mid-shift.
Our pipefitters are Local 562 trained and mobilize from O'Fallon to plants across the metro and a 2-hour radius, including Wentzville, Arnold, Washington, and Troy.
Don't see your city below? We work the entire metro and a 2-hour radius from O'Fallon, MO. View full service area →
St. Charles County
Warren County
Need Process Piping in the St. Louis Area?
Send your spec or walk us through the plant — we'll scope the fabrication and install.