The art of the system dump. Putting restaurants back on line. Don’t Panic!

All fire systems are made to go off. Every single one. Often I think of my job as playing with mousetraps. Most career restaurant chefs have stories of them discharging, I’ve seen them first hand.  The causes are all over the map. The obvious best cause is fire, but they can be caused by a myriad of things. In 22 years you would think I’d seen it all, but the reasons for a discharge just keep coming. Recently i took care of a system where a burglar had tried to access the building through the ventilation shaft, kicked the detection line and got showered with wet chemical.I almost felt bad for the guy.

Regardless of how they go off, they need to be put back on line. That is where I come in. In a system dump all of the chemical in a system is put through the discharge piping. Anything under the nozzles is covered in chemical, usually a solution with a potassium base not too dissimilar to salt water. The duct and plenum get hit as well.

The first thing I do is establish cause.Fire is the most obvious, but there are many ways a system can be set off. Not turning on fans, broken cables, breaking a link while cleaning, disgruntled employee pulling the pull station.  The reason the why matters is in trying to avoid future recurrences, except with fire.  Fire should always set it off.

If there is food or cooking oil underneath it has to be tossed. By the time I get there generally an initial wipe down has been done and the restaurant is in full damage control mode. I then rinse the system and dump nitrogen through the lines creating a second discharge. The goal is to clean out and dry the piping to avoid corrosion. I also use it as an opportunity to make sure it is operating properly. If there is broken pipe or clogged nozzles it is a good time to get them fixed Links are replaced, caps put on and the restaurant is good to go finishing the cleanup. Soapy water neutralizes and cleans it right up. After blowing it out the customer starts reassembling the kitchen but they’ve often missed the next meal rush.

The next step is resetting the system. When the system went off it killed power, killed gas, triggered the automan, set off alarms and whatever additional shut offs that have been tied in. Getting this back to normal is a top priority.

Ansul gas valve.

Tank recharge is the last step. With my operation recharging is all done on location as long as the restaurant has stayed current on tank testing. Most companies will haul the tanks into their shop for recharge, leading to additional downtime or unprotected cooking conditions.

Once the tanks are back up to snuff they are reinstalled and the customer is back to normal operation. In most cases it is an hour to three from the moment I land on site to walking out the door.

Its never pretty, but I do what I can to get the restaurant back up to full operation as quickly as possible. Even though the work I do isn’t a cheap repair, loss of new revenue does far more damage to the restaurants than my bill. I have my methods pretty dialed in and I very consciously carry the correct inventory to quickly restore normality.

Don’t panic!  I’ve got this.

Back on line.

 

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Fire system overview. The myth of the grandfather clause.

Restaurant fire systems is a big subject, with a relatively short history. It is where I am rooted, and the basis for what I do, and what I’ve done. When I first started doing this in the 90’s there were still dry chemical systems in service. The manufacturers were moving towards wet chemical, but the UL 300 testing standard was barely a thing and had not become a mandatory requirement. For perspective, NFPA 96 was when UL300 was introduced, and I started in the industry in 1997. It wasn’t until much later, the early 2000’s that they started instituting drop dead dates for kitchen fire systems in Utah, effectively killing any grandfather clauses.

So what changed and why the new code? Kitchen systems work through the process of saponification. Basically the fire suppression systems drop chemicals on to the cooking media, which is fat, and renders the fat into soap. The soap then suppresses the fire.  The restaurant industry moved away from rendered lard, and towards vegetable oils in their cooking processes. The difference is the flash point of animal oils is 550-600 degrees Fahrenheit.  Vegetable oils at 685 degrees plus. The UL300 wet chemical added a cooling element. The old dry chem systems were dumping and the fryers were reigniting. Systems are a one shot wonder and buildings were burning down due to re-ignition. There are no UL-300 listed dry chemical suppression systems. Contrary to popular belief, there are no grandfathered fire systems that meet code.  Saying a system is grandfathered does not change the nature of fire, isn’t worth the lives of your employees, and definitely not worth my livelihood or freedom.

How do they work? All restaurant systems are equipped with two methods of actuation. They have a manual release(pull station) and automatic detection in the form of a heat detector or fusible link.  At the time either of these devices are activated a few things happen.

The biggest thing that happens is the chemical is released onto the cooking media. This is a mess, but not like the dry chem, sodium bicarbonate days. The wet chemical, potassium carbonate, is very focused and only dumps on the cooking appliances and near vicinity. The dry chem of yore used to go everywhere.  The whole restaurant wound up in a cloud.

All sources of fuel are eliminated. Whether cooking with gas or electricity, the system shuts it down.

Building alarms are triggered.  That is right.  Not just the kitchen but the entire building.  Gotta get folks out of there.

Unlike the dry systems, generally the fans stay on. The idea is to suck the chemical up the duct to put out the fire.  On the old dry chem systems they didn’t want the chemical sucked out.

Make up air is up for debate locally.  Some AHJ’s want it on some want it off.  As always, the locals hold the final say regardless of the way the code is written.

There are many other options like gas reset relays, but this is the most basic of overviews.

There is nothing fun about a system discharge, but they do happen and are required for the saving of lives and property. I’ll get into system dump stories in future posts.