Technical FAQ: Ammonia Based Systems
General System Engineering
ASME (American Society of Mechanical Engineers) codes primarily govern the design and fabrication of the pressure vessels themselves (e.g., Section VIII). IIAR (International Institute of Ammonia Refrigeration) standards, specifically IIAR-2, provide the comprehensive requirements for the safe design, installation, and operation of the entire ammonia system. RM Technologies ensures every integration meets both the vessel-level and system-level standards.
While both are generally compatible with ammonium hydroxide, 316L (Low Carbon) offers superior resistance to pitting and stress corrosion cracking (SCC) in environments where chloride contamination or high temperatures are present. For high-purity pharmaceutical or electronics applications, 316L is the industry standard to ensure zero metallic leaching.
Safety & Compliance
For Anhydrous Ammonia, the threshold is 10,000 lbs. For Aqueous Ammonia (concentrations of 20% or greater), the threshold is 20,000 lbs. If your facility holds these amounts at any one time, you are required to implement a full Process Safety Management (PSM) program and submit a Risk Management Plan (RMP).
Industry best practices and most manufacturer guidelines recommend bump testing quarterly and a full calibration every 6 to 12 months. In harsh industrial environments or where sensors are exposed to constant low-level background ammonia, more frequent calibration may be necessary to prevent "sensor drift.
Urea & NOx Reduction
Yes, but it requires significant engineering modifications. Because urea is a solid or liquid solution, you must add a Urea-to-Ammonia (U2A) hydrolysis system or a specialized decomposition chamber. RM Technologies specializes in these retrofits, allowing facilities to eliminate high-pressure ammonia storage while maintaining their existing SCR catalyst infrastructure.
"Salting out" occurs when the temperature of a urea solution drops below its saturation point (approx. 32°F for a 32.5% DEF solution), causing urea crystals to form and clog lines. We prevent this by engineering heat-traced piping, insulated storage tanks, and recirculation loops that keep the reagent above its crystallization temperature.
Maintenance & Longevity
SCC is often invisible to the naked eye until a leak occurs. It typically forms in the "Heat Affected Zone" (HAZ) of welds in anhydrous service. We recommend regular Non-Destructive Testing (NDT), such as Magnetic Particle Testing or Ultrasonic Testing, to identify these cracks before they lead to a catastrophic failure.