ASME B31.9 / IMC 1203.4

ASME B31.3 Table A-1 / NACE MR0175

Carbon steel is not suitable for concentrated sulfuric acid service at elevated temperatures. The acid will cause rapid corrosion and thinning, leading to catastrophic failure. Material selection must follow ASME B31.3 Table A-1 and NACE MR0175 guidelines for corrosive service.

ASME B31.9 — Building Services Piping

Hydronic heating systems require an air separator to remove entrained air. Air in the system causes noise, corrosion, reduced heat transfer, and pump cavitation.

ASME B31.9 / Crestline Hydronic Specification

The system exceeds the normal-pressure hydronic rating of 125 PSI. At 145 PSI static pressure at the base, all components in the lower floors must be rated for high-pressure hydronic service (up to 250 PSI). Static head in tall buildings is a common source of overpressure — every 2.31 feet of building height adds approximately 1 PSI. A 15-story building can easily generate 60+ PSI of static pressure alone. The contractor's argument about pump pressure is irrelevant; the total pressure (static + dynamic) is what matters for component ratings.

ASME Boiler and Pressure Vessel Code, Section IV — HG-400

ASME BPVC Section IV requires that safety relief valves on hot water boilers be set at or below the maximum allowable working pressure (MAWP), never above it. A valve set at 157.5 psig on a 150 psig rated boiler allows the vessel to be pressurized beyond its design limit before the valve lifts. This defeats the purpose of the safety valve, which is to prevent overpressurization at or before the rated limit. The valve must be replaced with one stamped at 150 psig or lower. This is a mandatory violation that will fail jurisdictional inspection, and the boiler must be taken out of service until corrected.

ASME BPVC Section I PG-71 / ASME B31.1

ASME BPVC Section I and ASME B31.1 require PRV discharge to be piped to a safe location where released steam cannot endanger personnel. Discharge into an occupied walkway creates severe burn and scalding hazards. PRV outlets must be directed vertically upward or to a safe discharge point away from personnel areas.

ASME BPVC Section I PG-71 / ASME B31.1 Section 122.6

This fails code on multiple counts. First, ASME Section I PG-71.4 prohibits reducing the discharge pipe below the area of the PRV outlet — the 2-inch to 1.5-inch reduction restricts flow and creates excessive back pressure on the PRV, reducing its relieving capacity. Second, the discharge termination at 4 feet above ground level creates a scalding hazard to personnel in the equipment yard; discharge must be directed to a safe location where personnel cannot be exposed to the steam release. Third, the horizontal discharge piping without a drain will accumulate condensate, which can cause water hammer when the PRV lifts. PRV discharge piping must be self-draining with a drip pan elbow or weep hole at the low point per ASME B31.1 Section 122.6.