Pressure Vessel PWHT

On-Site Pressure Vessel Heat Treating — ASME-Compliant PWHT, At Your Facility

Gulf Coast Combustion performs on-site post weld heat treatment for large, thick-walled, code-critical pressure vessels using direct gas fire combustion. We bring the equipment to your yard and heat treat the vessel where it sits. No transport. No furnace queue. No size limits. Every job is executed to ASME Section VIII Division 1 / UCS-56 or your customer-specified WPS, with a full documentation package in hand before our trucks leave.

We serve fabricators building code vessels for oil & gas, chemical processing, and petrochemical applications. If you need a heat treating partner who shows up, executes clean, and documents every degree, call owner James Benefield directly at 832-797-3428. He answers calls and texts personally, including short-notice and emergency jobs.

Everything You Need to Evaluate On-Site PWHT

Whether you are pricing a job, weighing on-site against a furnace, or vetting a contractor, start here. These are the resources fabricators and plant teams use most.

What It Costs

Free PWHT Pricing Calculator

Enter your vessel specs and get a budgetary estimate in seconds, built from GCC’s actual job data. No email required.

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On-Site vs. Furnace

Should You Ship It or Treat It On-Site?

Cost, schedule, risk, and documentation compared side by side for large pressure vessels. The full decision breakdown.

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Code & Standards

The Fabricator’s Complete Guide to PWHT

Code requirements, technical parameters, thermocouple placement, and documentation standards, in plain language.

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Choosing a Contractor

How to Vet a Heat Treating Contractor

Anyone can own the equipment. Not everyone can cook a vessel. What separates a reliable PWHT partner from the rest.

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How On-Site Pressure Vessel PWHT Works — No Furnace Required

We use direct combustion gas fire, natural gas or propane, to bring the entire vessel up to soak temperature on your floor. The heat source works from inside the vessel, not around the outside. The vessel becomes the furnace. That approach is what makes on-site the practical choice for vessels where shipping to a furnace stops making sense: on-site, from roughly 10 feet to 120 feet and beyond, and weights from 30,000 lbs to over 600,000 lbs.

Our gas trains fire up to 8 million BTU per console and our high-velocity blowers are built for large, heavy-wall vessels: the kind that need precise, even temperature control across significant wall thickness to reach full stress relief through the weld and heat affected zone. More than 90% of our work is on-site gas combustion PWHT. It is what we specialize in, and it is nearly all we do.

As Featured In

The Fabricator — North America’s Leading Metal Fabricating Publication

James Benefield wrote the Welding Strategy article in the August 2026 issue: heat treating large pressure vessels where they sit. Four PWHT methods, what actually happens inside the steel, and the point where a furnace stops being an option.

Read the Article

Thermal Processing Magazine — The Industry’s Leading Heat Treating Publication

James Benefield wrote the technical article the industry needed someone to write: what on-site direct gas fire PWHT actually requires to get right.

Read the Technical Article

Complete, Code-Compliant Documentation on Every Job

Every PWHT cycle we perform is fully documented with chart recorder traces showing heat-up rate, hold temperature, hold time, and cool-down rate, traceable to specific weld seams on your vessel. That documentation becomes part of your permanent vessel record and meets ASME Section VIII requirements. Your QC team can witness the process directly, on-site, from start to finish. We use Type K thermocouples with capacitor discharge attachment and NIST-calibrated Chino recorders to monitor every phase, from initial heat-up through soak and controlled cool-down.

What Happens After You Call

Want to know how long we’ll be on your floor? Here’s a complete breakdown of the on-site PWHT timeline, from setup to pack-out. Curious which vessels we treat most? See pressure vessel PWHT by vessel type.

Mobile PWHT in Action

Vessel Types We Regularly Work On

Gulf Coast Combustion performs on-site PWHT across the full range of pressure vessels fabricated for oil & gas, chemical processing, and petrochemical applications.

Where We Work

On-Site PWHT Across Texas, the Gulf Coast & Nationwide

Based in Spring, TX. We mobilize anywhere in the U.S. Find your region, from Houston and the Permian Basin to Baton Rouge, Corpus Christi, Dallas, and beyond.

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