MEP PE Stamp in Pinal County, AZ: What Gets Reviewed Before Sealing?

The mechanical review starts with the load calculations, because everything downstream inherits their assumptions. I check that the calculations used Pinal-appropriate outdoor design conditions — the extreme dry-bulb peaks, the solar exposure, the monsoon-season humidity — with internal gains modeled realistically for the occupancy. Equipment selection gets matched against the peak sensible load with a margin that covers the worst week, not the average one, and I look hard at the ventilation strategy: code-required outside air in a desert climate is a sensible and latent load that has to be accounted for in equipment capacity, not just shown as a duct connection. Rooftop units dominate the county's commercial stock, so I also verify the mechanical-electrical-structural triangle: unit weights and curb details coordinated with the structural set, electrical loads reflected in the panel schedules, and service clearances that a technician can actually work in. The sealed drawings need to show these systems working together, not as separate sheets that happen to be in the same package.

Whether the reviewer sits at the county or a city, MEP plan check reads the set the way a contractor builds from it: does the logic hold together? Riser diagrams get checked against the floor plans — every fixture on the plan should trace to the riser, and the riser should show pipe sizing, slopes, and venting that satisfy the plumbing code. Panel schedules get checked against the electrical riser: calculated loads, breaker sizes, and feeder sizes must agree, and the service calculation must support the whole building. Plumbing fixture counts get checked against occupancy, and specialty items like commercial kitchen exhaust or grease waste get extra attention because they carry their own code requirements. The PE's pre-seal review runs this same gauntlet, which is the point of review-and-seal: corrections from your own engineer get fixed in days, while corrections from the AHJ cost a full review cycle. Energy compliance documentation gets reconciled against the sealed design too — envelope values, lighting power densities, and equipment efficiencies matching what the drawings actually show.

An MEP package is ready for the PE's review — and then for the AHJ — when these items are resolved. Coordination between the MEP sheets themselves is where most corrections originate. • AHJ confirmed: Pinal County Community Development vs the incorporated city, verified by parcel lookup • Arizona-licensed PE in responsible charge of the MEP review • HVAC load calculations with realistic desert design conditions and ventilation loads broken out • Equipment schedules matching the mechanical plans, with capacity verified against the loads • Plumbing plans, riser diagrams, and fixture counts coordinated and code-compliant • Electrical plans, panel schedules, and riser diagram in full agreement on loads and protection • Energy compliance documentation reconciled against the actual sealed design