Techalloy Company, Inc. - Northampton Wiire Plant - Executive Summary

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Northamptom Wire Plant 
Who we are & What we do 
Techalloy Company, Inc., a manufacturer of specialty wire products, is a unit of USINOR, a diversified worldwide supplier of steel products.  The Northampton Wire Plant specializes in the production of stainless steel drawn wire products ranging from large gauge wire, used to make stranded structural building cable, to very fine gauge wire, used in the manufacture of automotive air bag fabric.  This facility has been in continuous operation at this location since 1948. 
Management Commitment 
Techalloy and USINOR are committed to a safe workplace and a clean environment.  The emphasis is proactive and founded upon the principle of prevention:  the best way to respond to an problem is to prevent it in the first place.  Equipment and systems are designed and selected to be safe, reliable, and durable.  Methodology and procedures are carefully considered, thoroughly planned, 
and attentively implemented.  The Northampton Wire Plant is certified to ISO 9000. 
Hazardous Materials Policy 
It is policy to eliminate the use of hazardous materials wherever and whenever possible.  There are active toxics use reduction and hazardous waste minimization programs in place.  The hierarchy of the efforts in this area start with material substitutions, followed by process modifications, next by recycling of materials, and finally by waste treatment modifications. 
Health and Safety Policy 
The health & safety program prioritizes engineering controls to eliminate hazards.  Work practice controls are used either as supplementary measures or when engineering controls are not possible.  Employees are trained to understand the hazards associated with workplace chemicals; the precautions necessary for their personal protection; the methods & procedures required for the safe use, handling, and proper disposal of chemical products; and emergency procedures for spills, releases, 
and other unplanned incidents or events. 
Emergency Planning 
The emergency plans used for preparedness & prevention planning, contingency planning, and employee training have been coordinated with local emergency response organizations.  Techalloy has hosted drills at this facility for the regional Hazardous Materials (HAZMAT) Team and the local fire department.  Periodic safety inspections are conducted by local fire prevention officials, insurance carriers, corporate representatives, and private consultants. 
our process 
In the process of drawing wire, raw stock, called rods, are mechanically pulled through a series of circular dies of ever decreasing diameter until the desired size and mechanical properties are achieved.  This process causes the wire to become brittle.  In order to restore elasticity and strength to the drawn wire, it is heat treated in a process called annealing. In this process the wire is heated in an oven containing a shielding atmosphere and then cooled & clea 
ned in a mildly acidic aqueous bath. 
Why the Risk Management Rule Applies to us 
The risk management rule lists ammonia as one of the regulated substances.  Ammonia gas is used to produce the shielding atmosphere for annealing.  Anhydrous ammonia gas is dissociated yielding a mixture of inert nitrogen and hydrogen gas.  The hydrogen gas is fully consumed in the process, thereby scavenging oxygen and recovering some heat value.  The Nitrogen displaces any oxygen remaining in the annealing oven and is ultimately returned to the atmosphere where it originated.  The ammonia that supplies this process is stored in liquid form. 
why use ammonia 
Nitrogen is the most practical shielding gas available for heat treating applications.  Ammonia is the best source of nitrogen for shielding purposes in heat treating.  The presence of hydrogen gas generated along with the nitrogen in this application results in a necessary surface condition in the final product which is not achieved when hydrogen is  
absent.  The energy savings generated when the hydrogen is burned is an added value.  Also, combustion of hydrogen is complete and clean.  All efforts to substitute for ammonia have been ineffective. 
How the Ammonia System Works 
The ammonia portion of this process is a very simple, time tested, and proven design with one moving part.  Liquid is stored in a sealed ASME storage vessel until a call is received from the annealing ovens.  Upon starting the annealing ovens, the ammonia dissociation unit is started by an interlocked electrical control signal. 
The dissociator is simply an electrically heated air tight chamber that breaks the ammonia gas into its constituents, nitrogen and hydrogen.  When the dissociator reaches process design temperature, an interlocked electrical control signal opens a pressure regulating valve that initiates a path from the storage tank to the dissociator. 
When the pressure regulating valve opens, ammonia evaporates and the resulting gas is moved through t 
he interconnecting piping under the natural pressure gradient between the tank and the dissociator. 
Similarly, the pressure gradient between the dissociator and the annealing ovens provides the motive force that transports the dissociated hydrogen and nitrogen through interconnecting piping to these ovens. 
The dissociator cannot operate until the annealing ovens are operating.  The pressure regulating valve cannot open until design operating temperature at the dissociator has been proven.  If the dissociator will not operate, an alarm is sounded. 
automatic safety system 
The facility has an automatic water deluge mitigation system with manual initiation override capability.  City water is supplied through a three inch supply pipe to a series of distribution nozzles that blanket the ammonia storage tank and the surrounding area with a dense spray of water saturating the air around the tank upon actuation and continuing uninterrupted until manually stopped.  An ammonia sensor continuously 
monitors the atmosphere near the tank.  If ammonia is sensed above a pre-set concentration, a valve is electrically actuated releasing water to flow to the system and sounding an alarm.  The valve is the only moving part in this system. 
Worst Case Release Scenario 
Under federal regulation a worst case scenario must be considered to include a sudden release, ten minutes in duration, of the entire contents of a full tank  The resulting gas plume must be considered to remain at ground level.  It should be noted that, even in this "worst case", the resulting plume will not fill the entire circle formed by the radius from its source to its endpoint.  The plume will rather tend to form in an expanding band of gas along this radius until ultimately dispersing. 
In practice the ammonia tank is filled ten to fifteen times per year and is, therefore, only full between ten and fifteen days per year.  It takes nearly six hours to fill the tank using a pump and a two inch supply  line.  It would  
require the sudden opening of a huge gaping hole to release gas at the rate mandated. 
The worst case parameters also specify a scenario which would occur only on very calm, overcast, night between late May and early October, a night without rain.  The complete failure of the water deluge mitigation system, concurrent with these conditions, must also be assumed. 
Alternative Release Scenarios 
Alternative scenarios which account for more probable release rates, more likely atmospherics, and allowing for the proper operation of the safety system; show that the resulting release would remain essentially within the boundaries of the facility. 
Five Year Accident History 
The risk management rule requires a statement concerning any accidental releases of ammonia which may have occurred in the past five years.  There have been none. 
Ongoing Safety Improvements 
The presence of ammonia at these premises is taken seriously.  systems, equipment, and procedures are diligently examined for safet 
y improvements.  The following improvements are in process:  erecting improved traffic barricades to prevent the already unlikely event of a vehicle colliding with the tank,  providing back-up emergency power for the sensor and the actuator of the water deluge safety system, and installing a thermal cut-out device for the heater used to heat the input piping to the dissociator in the winter season. 
From our Personal Point of View 
The management offices at this facility are located on the second floor of the building, immediately adjacent to the ammonia tank.  The management staff would be the first to experience the effects of a release.  There is, therefore, an urgent and obvious self interest in preventing such an event.
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