This is one of the more ridiculous requirement in NFPA. What difference it makes if you fill it in 24 hrs or 48 I don't know but it's there and hope fully you can do it without excessive coat or agree with the fire authority that is impractical.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
This is one of the more ridiculous requirement in NFPA. What difference it makes if you fill it in 24 hrs or 48 I don't know but it's there and hope fully you can do it without excessive coat or agree with the fire authority that is impractical.
Well since insurance companies drive a lot of the codes and standards for the last 100 plus years, they want the tank full to provide fire protection to reduce the loss potential. I am sure the 8 hours time limit was a 3 day debate by the NFPA committee with some wanting no limit and some wanting 2 hour limit. After all the yelling and screaming they all agreed on 8 hours. I say this as being a past member of a NFPA committee.
If you are self insured and the AHJ can live with 48 hours.....more power to you.
It doesn't matter how you full it as long as you can do it in 8 hours. Any tank can be filled in 8 hours if you have enough money to hire a fleet of tanker trucks.
My thoughts, filling the tank within an eight hour period is not as ridiculous as suggested above. Although, it may seem to be an arbitrary number, sprinklered properties needs to have the available water within some reasonable time, consequently, eight hours was deemed acceptable probably to all interested parties such as insurance companies, local jurisdictions and owners.
This is for a fire water tank which gets filled up and then just sits there. So long as you fill it up before you occupy the premises then who cares if it takes 16 hrs, 24 hrs or more. It is an utterly arbitrary number which bears no relationship to anything other than some people thought it needed to be specified instead of saying " The tank should be full before occupying / using the premises / storring flammable material" and "time taken to fill the tank to be agreed with the AHJ taking account of local conditions / water sources / fill rate".
There is no need whatsoever to place such an onerous condition for something that happens once or twice in a tanks lifetime (empty to full). I would simply apply to the AHJ stating why filling the tank in that time is ridiculous, but accepting that the tank needs to be full before the facility can be used.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
This is one of those situations where a waiver should be raised, because we are talking about a prescriptive and not risk-based fire protection. It can easily be proven and documented that 8 hours refilling time is as good as 10 hours. Waiver is normally required to justify deviation from the prescribed values.
From an insurance point of view, the property/ building owner receives a significant reduction in insurance premium because of the automatic fire protection on site. The company I worked for had a detailed fire protection impairment program requiring the "insured" to notify us whenever a fire protection system was out of service. Depending on the operation hazard, $ at risk, our underwriters would actually purchase reinsurance when the protection was out for more than 8 hours. Sometimes that cost of reinsurance was pasted onto the client or we ate the cost. So a tank supplying the fire protection on site empty for 24-48 hours, someone is paying for it.
NFPA 25 requires internal inspection of the tank every 5 years, not too long ago they required the tank to be emptied for the inspection. So in this case it was not something that never happened, it did occur every 5 years.
About the only time I did not enforce the 8 hour time limit was when the tank was for a secondary water supply, where the tank and pump was a backup to the adequate city water supply.
So who put that 8 hour time limit into the standard....the insurance companies and property owners ( they did not want to pay those reinsurance $$$) who were on the committee.
What would an average gallon capacity water tank be?
Given that number and eight hours what would be the minimum flow to fill it in eight hours??
It depends on the occupancy and hazard...warehouse with ESFR typically 100K gallons, nonESFR 250+K, power plant where they use process water (cooling) and fire protection in one tank 1 million gallons!
