As a versatile chemical raw material, ammonia(NH3) plays an increasingly prominent role in applications ranging from refrigeration to synthetic ammonia production and eco-friendly materials. To ensure safety and environmental protection, high-precision instruments must be used to monitor the storage, transportation, and application of ammonia.
For example, for liquid ammonia, a Coriolis mass flowmeter is the preferred choice for flow monitoring, while a guided-wave radar level transmitter is recommended for measuring the liquid level in the tank. For gaseous ammonia, a vortex flowmeter is suitable. A 316L diaphragm smart pressure transmitter can be used to monitor ammonia pressure. Additionally, a Pt100 thermoresistor, equipped with a 316 stainless steel protective sheath, is used to monitor temperature.
In industrial applications, ammonia primarily appears in three forms: pure gaseous ammonia, pure liquid ammonia (anhydrous ammonia), and aqueous ammonia (ammonia solution). This is also one of the reasons why measuring it presents numerous challenges.
| Ammonia | Liquid Ammonia | Ammonia solution (20–28%) | |
| Pressure | Typically low pressure in pipelines (vaporized ammonia) | Pressurized storage at ambient temperature: 1.2–1.6 MPa / 174–232 psig Refrigerated storage: near atmospheric pressure | Storage tanks at atmospheric or slightly positive pressure |
| Temperature | Ambient or heated; keep above the saturation temperature to avoid condensation | Pressurized storage: ambient temperature Refrigerated storage: -33.4 °C / -28.1 °F | Ambient temperature |
| Impact of instrument selection | -For measuring ammonia flow, use a vortex flowmeter with temperature and pressure compensation, or a thermal mass flowmeter that measures mass flow directly. -For measuring ammonia pressure, ensure that the pressure-sensing line is protected against condensation. | – For measuring the flow rate of liquid ammonia, a Coriolis mass flow meter is the preferred choice; electromagnetic flow meters are not suitable. – For measuring the liquid level of ammonia, guided-wave radar is the preferred choice. – For measuring the pressure of liquid ammonia, ensure that the lower operating temperature limit is verified for the specific cryogenic conditions. | – For measuring the flow rate of ammonia solution, a standard electromagnetic flowmeter is sufficient. |
Sino-Inst has many years of experience in industrial process measurement and control, and now provides customized solutions for special operating conditions of ammonia storage, transportation and application. Our instrumentation covers a comprehensive range of needs, including flow, level, pressure, and temperature measurement. With decades of professional experience in chemical and process measurement, Sino-Inst has provided a wide range of ammonia measurement instruments and solutions to users in various countries.
Whether it’s vapor layers and boiling liquid surfaces, sealing permeation and diffusion, or even harsh operating parameters such as low temperature and high pressure, we can provide you with customized solutions.
FLOW · LIQUID AMMONIA
First choice for liquid anhydrous ammonia. Measures mass flow and density directly, with no conductivity required. Suited to unloading, transfer and batching; keep the line subcooled to avoid flashing.
FLOW · LIQUID AMMONIA, LOW FLOW
Positive displacement meter for small-bore, low-flow liquid ammonia dosing. High repeatability in clean liquid service; specify stainless steel construction and ammonia-compatible seals.
FLOW · AQUEOUS AMMONIA ONLY
For aqueous ammonia (20–28%), such as SCR/SNCR denitrification dosing. PTFE liner with 316L or Hastelloy C electrodes. Not suitable for anhydrous liquid ammonia, which is non-conductive.
FLOW · AMMONIA GAS
For ammonia gas lines and vaporized ammonia feed to SCR systems. Use with temperature and pressure compensation to report standard volume or mass flow.
FLOW · AMMONIA GAS, LOW FLOW
Measures mass flow of clean, dry ammonia gas directly, without separate temperature and pressure compensation. Calibrated for ammonia gas on request.
LEVEL · ANHYDROUS AMMONIA TANKS
Recommended for pressurized and refrigerated anhydrous ammonia tanks. Unaffected by boiling surfaces and vapor layers. Coaxial probe or bypass chamber installation available.
LEVEL · AQUEOUS AMMONIA TANKS
Non-contact level measurement for aqueous ammonia tanks. Narrow beam suits small nozzles. For anhydrous ammonia with dense vapor, confirm the range with our engineers.
LEVEL · OVERFILL PROTECTION
Independent high-high level switch for ammonia tanks, receivers and separators. No moving parts and no calibration needed; use alongside a continuous level transmitter.
PRESSURE · ALL AMMONIA SERVICE
316L diaphragm smart pressure transmitter for ammonia tanks, pipelines and refrigeration receivers. Copper-free wetted parts; specify ammonia-compatible seals.
TEMPERATURE · ALL AMMONIA SERVICE
Pt100 sensor in a 316 stainless steel thermowell for ammonia tanks and lines. Saturated ammonia pressure and temperature can be cross-checked for diagnostics.
Case: Custom 300 MPa Pressure Transmitter for Ammonia Service (Inconel 718 diaphragm, cooling fins, cone-seal connection)