Facts about NH 3
Did You Know?
What Are the Common Causes of Releases?
Operations and maintenance failures, equipment failures, and process failures are the three leading causes of accidental releases of ammonia. Significantly fewer releases are caused by unauthorized activity, natural events, and fires.
Equipment Failures include defective equipment design, construction and installation that result in overflowing containers, and leaking piping, valves, and gaskets.
Process Failures include pressure, temperature, flow and fluid chemistry changes that result in tank and/or piping ruptures.
Easy Steps to Lessen the Chances of an NH 3 Release
Ammonia refrigeration facilities should be aware of the potential hazards of ammonia releases and of the steps that can be taken to prevent such releases. They should be prepared to respond appropriately if releases do occur. Here are steps that ammonia refrigeration facilities could take to prevent releases and reduce the severity of releases that do occur include:
e) control valves
f) all electrical safety(s), including
3)low oil pressure cutouts
g) ammonia detectors
h) emergency response equipment, including,
1) air monitoring
3) level A suit
4) purifying respirators
Properly post ammonia placards (i.e. NFPA 704 NI-I3 diamond) and warning signs in areas where ammonia is being used as a refrigerant or being stored (for example, compressor room doors). Properly identify the chemicals within the piping system(s); label all process piping, i.e. piping containing ammonia, as "AMMONIA." Label must use black letters with yellow background. (This requirement is not the same as the in-house color coding system.)
Establish emergency shutdown procedures and instructions on what to do during and after a power failure.
Perform vibration testing on compressors. Document and analyze results for trends.
Consider using the compressor room ammonia detector to control the ventilation fans.
Ensure that good housekeeping procedures are followed in the compressor rooms.
Keep an accurate record of the amount of ammonia that is purchased for the initial charge to the refrigeration system(s) and the amount that is replaced. Consider keeping a record of the amount of lubricating oil added to the system and removed from the system.
Consider installing ammonia detectors in areas where a substantial leak could occur or if the facility is not manned 24 hours/day. The ammonia detectors should be monitored by a local alarm company or tied into a call-down system.
Ensure that the ammonia detectors are calibrated regularly against a known standard. Check the operation of ammonia sensors and alarms regularly.
Replace pressure relief valves (PRVs) on a fiveyear schedule; document replacement dates by stamping the replacement date onto each unit's tag.
Replace single PRVs with dual relief valves. A dual relief valve installation consists of one three-way dual shut-off valve with two pressure safety relief valves.