How long should an engineer take to refill wet chemical?

[Guest Michael]

Hi I want To know if a 6kg wet chemical retest discharge can be done in the back of van and if so how long it would take as I recently had it done without knowing it until the bill come and it didn't seem right as it was done in just a few minutes.

[Shawn Bosworth]

It is entirely possible that a stored pressure wet chemical unit could have a TDR (Test Discharge Recharge) performed, if the engineer had the correct facilities in the van.

He would need a place to discharge the extinguisher as you can't just spray these chemicals down the drain (typically you would carry a large liquid container). He would also need the correct wet chemical concentrate in the correct quantity, access to fresh water with a measurement marked bucket and a nitrogen cylinder to pressurise the extinguisher.

If all of these were available in the van it would probably take 10 to 20 minutes to perform a TDR depending on how smoothly things went.

 

[AnthonyB]

Possible, but unlikely.

Some traditional fire extinguisher companies do carry out Extended Services on liquid extinguishers, but most will replace new as the trade cost 'out of the box' is comparable with the cost of an Extended Service once you've thrown in labour time, environmental compliance, and the cost of having all the parts, chemicals and charging equipment on every van.

Plus it's years and years and years since engineer's training courses included recharging so there is a large number of engineers that don't know how to fill an extinguisher.

You are looking at

• time to take the extinguisher to the van
• finding a suitable foul drain for legal discharge if the van has no agent tank
• a minute to empty the extinguisher
• a minute or two to remove the valve
• a few more minutes to strip the valve & change the O-ring and to rinse out the body (and where do they get the water to do this if they are at the van?)
• Another few minutes to blow the hose and dip tube and change the O-ring
• A few more minutes to refill the body with water (from where?) add the wet chemical concentrate and refit the valve
• A minute or two to fit the charging adapter, connect the Nitrogen cylinder in the van and pressurise the extinguisher and reassemble the hose
• A minute or two to fit the pin, pull tag, test the pressure gauge and affix the dot and to fill in the service label
• Time to bring the extinguisher back into the premises

I would suspect the extinguisher was taken to the van, labelled as Extended Serviced, and brought back........

[Guest Nick]

Maybe it has been rotated with van stock. For example I will carry some ready filled extinguishers and swap them over and then refill the ones taken from this site in my workshop. Most clients are happy with this method as long as you explain this is what you have done. Sometimes people wouldn't even notice that it was not their original extinguisher that they had back, but I always make it clear that they have had a service exchange unit. Also you may have been surprised at the cost of a wet chemical refill charge on your bill. Unfortunately wet chemical refills are expensive.