Do you Peak?
Fire Sprinkler Grid Systems that is. How do you hydraulically peak your automatic sprinkler system? Do you depend on the program you use for fire protection hydraulic calculations and just trust it implicitly? I have learned not to!
The basic premise of hydraulically peaking a gridded fire sprinkler system is that the hydraulically most remote area of operation will be on the most remote branch lines between the primary and secondary cross mains. The branch lines furthest away from the point where the feed main connects to the primary cross main.
The programs I used did a great job of calculation as long as you understand the assumptions and limitations. Many hydraulic calculation programs assume that the system is a box with a common sprinkler head spacing and elevation. Then they just shift the remote area by adding the distance between heads to one side and subtracting it from the other. This is perfectly acceptable if the spacing is typical, but this is not always the case. So unless the system is spaced evenly, I peak manually. I just use the automatic peaking feature to give me a starting point.
Yes, I know what your saying. It’s Hard, and the Building Department, Fire Marshall or other Authority Having Jurisdiction are approving my calculations now. Well, That’s only because they assume several things. First, that since a computer was used it’s correct. Second, that you know what you are doing. But the day when the AHJ stops making these assumptions is coming. They have been learning!
Will the remote area be between the mains or will out board heads be involved. Many programs assume the remote area will always stay between the mains. But that depends on how many outboard heads the system has.
How many outboard heads can I have? The easy answer is one half the number along the line in the remote area. My experience is that as long as you follow this rule, even if the remote area should include outboard heads, the difference is marginal. However if design considerations mean that the secondary cross main has more heads outboard, then a calculation should be done using the outboard heads.
Will the remote area be on the end grid lines. Right now everyone assumes this is the case, but there are situations where it will not be. I have seen calculations where the end line was sized larger than the rest of the grid to make it work. But then the remote area actually will shift across the lines and not parallel to them. Most programs assume peaking is parallel to the lines. Also, if the grid is not typical, but has different spacing along the lines due to steel, or changes in ceiling grid, the remote area will not necessarily be on the end branch lines.
So be careful. Computer programs are great tools, but you are still the one in the hot seat.
H.R. 1194: Fire Sprinkler Incentive Act of 2009
As an old timer in the business, I am a firm believer in educating people to be able to make informed choices. I tend to resist using the heavy hand of government to force the issue. But the Fire Sprinkler Incentive Act is not brute force, but an incentive. It changes the tax codes to change how sprinkler systems are defined as property for the purpose of depreciation. Those who know me will know that I am not a fan of the current unfair tax code. But it is the way things are for now. So as such I support this bill, H.R. 1194 and any companion bill the Senate may introduce.
But it is not going to be easy. This bill has been stuck in committee since February and not been presented for a vote. A similar bill has been presented at least 6 times before and all have died. Please contact your representative and indicate your support.
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This is a guest post by Martha Newbold. who writes for YourLocalSecurity.com. If you would like to Guest Post, check out the Guidelines here.
A quality sprinkler system is critical in safeguarding a business or residential building from the devastation that a fire can cause.
In the UK, the British Automatic Fire Sprinkler Association, known as BAFSA, is responsible for over 85% of all sprinkler installations in the United Kingdom. Their goal is to keep people informed about the benefits of having a sprinkler system, as well as being a significant stakeholder in fire safely legislation and standards.
Sprinklers in the UK must be installed to a certain standard. Domestic and residential buildings currently must comply with standard BS 9251: 2005, whilst the commercial and industrial building equivalent is standard BS EN12845: 2004. These safety and security legislations are scheduled to be revised in the near future as part of an on-going review of fire safety guidelines in the UK.