Forward flow testing of backflow preventors - Survey 3

[SprinklerDesigner2]

With work the way it's been I've been getting more into inspections and am concerned about due deligence.

From NFPA #25 2002

12.6.2 Testing.
12.6.2.1* All backflow preventers installed in fire protection system piping shall be tested annually in accordance with the following:
(1) A forward flow test shall be conducted at the system demand, including hose stream demand, where hydrants or inside hose stations are located downstream of the backflow preventer.
(2) A backflow performance test, as required by the authority having jurisdiction, shall be conducted at the completion of the forward flow test.

This is a big deal especially in those areas of the country where it's never been enforced.

Some states, I'll single out South Carolina, require provisions be made for forward flow testing in new installaitons, but for others forward flow testing is overlooked by both code and fire officials.

Not a problem if there is a fire pump with test header downstream or there's fire hydrants downstream.

If provisions haven't been made, I envision something similar to a test header for fire pumps, annual forward testing can become a big undertaking in itself. Suppose we could turn FDC check valve around but in some systems this isn't so easy to do. In some places, a pit for example, this can become difficult to accomplish.

Georgia has adopted NFPA #25 but at the prices given for inspections it's clear few, if any, are actually doing this part of the inspection.

Question: What is happening in regards to foreward testing in your state and, if it is pushed, what have you been doing as far as connections?

Thanks.

 

[cdafd]

even though it has been there since 2002

one the ahj has to adopt the 2002

or, the sprinkler company has to design to 2002 or better, if allowed by the ahj


we have been enforcing it for about two years

two ways if they can calc the main drain on a small system and show it will meet the demand we accept it.

I know some people will not accept the main drain

Or, on bigger systems, all they do is tee off the fdc line, after the check valve, with a normally closed valve and four inch open butt to the outside. We do not have high demand systems, so either one works.

Now with a number of ahjs around us, I know it is not being enforced, and also you get into where is the backflow located and which ahj agency is responsible for it????

we require a backflow in the building 99% of the time stacked on the riser, so we get responsibility by default.

 

[ryano669]

Here in Kentucky, it is not being enforced. However, we have installed several new systems with bfp's on military bases where the full flow test connection was required. Typically consists of a tee in the header/riser after the bfp, before the alarm check with a full sized line piped outside the valve room. Line has a normally closed valve inside with a flush connection outside similar to a fire pump test header. We install snoots with male hose threads outside so that hoses with water monsters can be used to meter the flow during a test.
In a somewhat related issue, we recently had an consulting engineer tell us that the metering was not necessary, and that as long as we flowed through an open pipe of the same size as the bfp, that was sufficient. I questioned the reasoning since NFPA specifically states that demand plus hose allowance must be flowed during the test. How can one verify you are flowing the demand without metering through a pitot assembly of some sorts? What if the bfp was only partially opening during the test? Simply looking at the discharge through an open pipe outside, I personally couldn't tell the difference. Are others measuring the flow during the test, or are we going too far?

 

[cdafd]

"""""including hose stream demand,""""

I missed that portion


ryano669

Good points not a hydraulic person and wondered some of your questions.

If you have an open butt four inch can you pitot it?? for gpm flow???

 

[SprinklerDesigner2]

"How can one verify you are flowing the demand without metering through a pitot assembly of some sorts?"

You can't.

Everyone here knows that.

We've all done sprinkler systems with a density of .60/2000 without a fire pump and what I can easily see here is a 6" forward test assembly with five or even six hoses required to achieve the 1,300 gpm or thereabouts required and if hose streams are somehow taken off downstream the backflow assembly we could easily be looking at 1,800 to 2,000 gpm.

What I am worried most about is liability... if NFPA 25 & 13 2002 is adopted then what? You do an inspection without a forward flow and the inspection is incomplete is what. What do you do if flowing the inspector's test and the alarms might annoy someone you don't do it? Of course not, you ring the bells because it is required.

If you do an inspection without the forward test, invoice the customer, get paid and just happen to have a fire where $30 million is lost you risk looking awfully stupid in court trying to explain the reason you didn't do the forward test is it was inconvienent or there wasn't any government enforcement action.

Maybe this has never happened but we can be sure someday, somewhere it will.

Kentucky? I've worked in many states and I wish every state/jurisdiction would model themselves after Kentucky.

 

[LCREP]

See this web site for some good photos of test headers, etc.

http://inspector911.com/forward-flow-test/305#more-305

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[SprinklerDesigner2]

LCREP,

See this web site for some good photos of test headers, etc.

http://inspector911.com/forward-flow-test/305#more-305

Thanks.

That's easy enough during initial installation and I would imagine you could easily satisfy most Ord Hazard II occupancies with two 2 1/2" hoses.

What's the coefficient of discharge from a reamed pipe? 0.80 or is it a little less? (I loaned out my fire protection handbook).

Depending on where the riser is rolling out hoses could be a problem in itself but you could get a more accurate reading through a 1 3/4" playpipe as opposed to an open pipe.

The problem lies with existing systems were provisions weren't made and you still have companies giving inspections for $80 to $100. Yeah, we got em. No way you could incorporate rolling out hoses into your test without increasing cost.

 

[LCREP]

How many contractors follow NFPA 25 to the letter?? Based on how many things we find wrong during our inspections, not too many here in NJ. I always ask for a copy of the last 3 years of inspection reports. When I see 3 different companies I know the building owner is looking for the lowest price and can care less about the fire proteciton on site. What is even better is when one company finds a tons of stuff and the next two have nothing listed. I then ask were any of these items listed repaired? Sometimes I hear "Oh no they were just trying to make money by listing all those things". Got to love it, most times the facilities have so many other things wrong we just do not insure them.

In these economic tough times I fear more of this stuff will happen.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[ryano669]

I left out some info about the "open but" connection. Actually he specified a custom fabricated sheet metal diffuser of some sort, installed over the open pipe, that wouldn't wash away landscape. Visualize a trough of sorts. Technically an open pipe with no way of measuring flow.
CDAFD- I guess you could pitot an open pipe if you knew the coefficient, as SD2 referred to.

 

[FFP1]

Any company who charges $80-$100 to perform the NFPA 25 inspection activites for a water-based fire protection system is simply not doing a thorough job AND they probably have absolutely no idea how much liability they are assuming when they perform the inspection services.

Just my opinion (after 19 years of personal experience).

 

[SprinklerDesigner2]

LCREP,

You are so right which is why we who 1)know what we are doing and 2) want to do it right need the help of enforcement official and insurance officials.

I don't do everything 100% called for, thinking of forward flows especially, because I would end up losing 90% of the inspection contracts I do have. Nothing good about being noble and broke.

But those same people who shop for price, who threaten if you write something up, will be the first to sue your rear end if something should happen.

It was just five and six years ago anyone, any bum on the street, could perform a sprinkler inspection. We had people, afraid we still do, who do "drive by" inspections for $50. I actually ran across one last year that was being done for $40.

Not counting a forward flow a plain Jane wet system with waterflow switch, water motor alarm bell and supervised alarm is going to take a minimum of 90 minutes to do and I've heard of some inspectors that were completing 6 and 8 inspections in a day. No way can you do your job halfway right and do 8 in a day.

Hey, ran into an interesting one today on a 500 gpm fire pump. System installed 14 years ago, has a Eagle Eye flow meter but no test header and to make matters worse the darn pump was installed in an interior room with everything going to a floor drain. To run a test header would be a major headache which I could easily see running $10K or better. Supposedly this has been tested every year, never a word said about it and along I come to be someone the owner can hate. To make matters worse it's a government owned building.

 

[LCREP]

SprinklerDesigner2,

Yea see this a few times a year especially in office buildings, even in a few hospitals. If the building does not have a standpipe system with a stair tower with an outside door, or no roof test header you are pretty much out of luck. Which is better yet when the put the test header in the pump room and then you have to run 500' of fire hose to get it outside. Got to love low bid jobs.

I had a hospital with a 2500 gpm fire pump with no test header and only a flow meter. They removed the test header 12 years ago when they added the last addition to the hospital, and forgot to relocate the test header. 12 years of a only flow meter testing, that is all they had, pump pasted with flying colors, fire department was OK with it too. I get our underwriters to back me, you put in a test header or we are off the account. They install 250' of 10" pipe for a new test header. We test the pump only can get 750 gpm before it goes to 10 psi. Call the water department, they check the valves and find it partially closed, they open the valve, we get 3750 gpm at 30 psi. They went from calling me a pain in the butt to saving their butt if they had a fire!

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[ContractorDave]

I have the on-line 25 so it's 2008 but I'm sure the 2002 still does the following:
13.6.2 Testing.
13.6.2.1* All backflow preventers installed in fire protection system piping shall be tested annually in accordance with the following: Etc, Etc and then down a bit: 13.6.2.2 Where connections do not permit a full flow test, tests shall be conducted at the maximum flow rate possible........ and thumbing thru 13 I don't see where it's called for in any reference to a backflow preventer that a means for a forward flow test shall be installed. It seems that 25 get's quite excited about doing the forward flow test 'just so' .... and then goes but-if-you-can't-oh-well. It seems to me to almost be a catch 22 for an inspector: Would you rather go into a down-town building with an 8" supply and DCVA and only find a 2" main drain and write it up as such or would you rather try and figure out what to do with 8" worth of system demand? I'm saying this given 13.6.2.2. I'm more than interested in this because I did exactly this yesterday, did an inspection on a system with an 8" Watts 774 that tied into a 6" header with only a 2" main drain available.



Regards
Dave

 

[ContractorDave]

... not actually THUMBING through 13 ....I don't think I even HAVE a paper copy anymore ...

Dave

 

[cdafd]

lightecho

would the verbage be there because of older systems that do not have the means to flow the demand, and not require it tobe retrofit???



and thumbing thru 13 I don't see where it's called for in any reference to a backflow preventer that a means for a forward flow test shall be installed

13 has 2007 flavor

8.17.4.6* Backflow Devices.
8.17.4.6.1* Backflow Prevention Valves. Means shall be provided downstream of all backflow prevention valves for flow tests at system demand.

 

[FFP1]

The maximum flow rate possible could be multiple yard hydrants flowing simultaneously, all of the 2 in. drain valves flowing simultaneously or at the very least you can flow the 2 in. drains, auxiliary drains and ITC's simultaneously if you only have one sprinkler system at the facility. It does not say maximum flow rate possible through one single device. Using multiple hydrants or multiple 2 in. drains will usually be the best common sense approach. 13.6.2.2 makes this approach acceptable; however, there is really now way to determine whether or not the flow rate exceeds the highest demand including hose streams........this allows for the conclusion that there is actually no requirement to confirm the forward flow test is at or above the highest demand including hose streams.

At some facilities it is not a huge problem to reverse the FDC check valve, but in my personal opinion, this action would justify a work order (separate from a typical inspection activity) due to the additional time/effort/liability associated with the process. The additional charge would be justified because a suitable test header was not installed to accommodate the forward flow test.

 

[ContractorDave]

cdfad

Geeesh right in front of me

Thx

 

[cdafd]

(1) A forward flow test shall be conducted at the system demand, including hose stream demand

Means shall be provided downstream of all backflow prevention valves for flow tests at system demand.

so are these two the same thing as far as demand???? or is one with out the hose fiqured in???

why cant these committees talk to each other????????????

 

[SprinklerDesigner2]

From NFPA 13 2002 Edition in Chapter 16 Systems Acceptance

16.2.5 Backflow Prevention Assemblies.
16.2.5.1 The backflow prevention assembly shall be forward flow tested to ensure proper operation.
16.2.5.2 The minimum flow rate shall be the system demand, including hose stream demand where applicable.

It's as plain as day in 13 but few designers make provisions.

On most light hazard systems a single, maybe two if water supply is really low, 2 1/2" hose valve right on the riser. Doesn't sound like much but with hose valves, the welded thread-o-lets, caps and labor I betcha we are looking at a minumum of $300 to $500 on your average system. 2 1/2" hose valves and caps are not all that cheap. Add to this the cost of dragging hoses and playpipes around for every annual test. Sucks.

Georgia has been on 2002 for a number of years now and I have yet to encounter a single system anywhere in the state where provisions have been made much less a full forward test conducted during acceptance.

It's getting real tight out there and $400 added to a small $20,000 job can certainly cost you the job in the current economic climate.

Ok, what about this. On a typical system come off the riser witha 4" outlet having a 4" butterfly valve, pipe it down similar to what we would have on a wall mounted FDC, then take it through the wall to a 4"x3" reducing assembly similar to a welded swaged nipple

http://www.canvil.com/pages/catalogs/snb-p1.htm

. Welded swaged nipple shown for left with an overall lenght of 9". Now all we would need is the is the coefficent of discharge for the 3" outlet or maybe we could safely assume a coefficent of discharge of at least 0.80? At 10 psi pitot )3.068 ID having C=0.80) we'd get 710 gpm which would do it for a large majority of the systems we install.

Then for larger systems we could use a 6" butterfly with a 5"x5" swaged nipple whch would offer close to 2,000 gpm @ 10 psi pitot.

Then another way would be simply to discharge the water opening the butterfly valve to the point where the residual pressure was less than system demand.

FPE input would be appreciated.

 

[SprinklerDesigner2]

How about instead of a 1 1/4 or 2" main drain we just make it s 2 1/2" main drain on 2 1/2 and 3" systems, a 3" main drain on 4" systems and a 4" main drain on 6" and 8" systems utilizing nothing more than a butterfly valve and a couple grooved fittings?

I couldn't imagine a 4" system where you couldn't achieve an adequate forward flow on a 3" main drain or a 4" main drain in the case of a 6" or 8" riser.

Lots of pluses here. A 3" main drain test on a 4" riser would have to mean a lot more than a 2" drain through an angle valve.

Also fast draining. If having to drain a system no longer would a couple of $60 an hour fitters have to wait around for the system to drain for an hour.

For a 2" main drain:
2" angle valve $47.79
2" weld thread o let $3.12
2"x 6' sch. 40 pipe $15.00 (guessed at this price)
2" 90 Deg Elbow $3.97
2"x4" nipple $4.53
2" 45 Deg Galvanized Elbow $8.16
2 2" Galvanized wall plates @ $4.72=$9.44
Total price of material: $92.01

Vs a 4" main drain
4" Butterfly Valve less tamper $200.00 (Guessed... the only price I had was with tamper so I took $40 off)
4" Grooved mechanical tee $27.88
4"x6' grooved sch. 10 pipe $15.00 (guessed at this price)
4" grooved 90 deg. elbow $10.63
4" grooved 45 degree elbow $10.38
6 4" grooved couplings @ $6.33 = $50.64
2 4" Galvanized wall plates @ $8.23
Total price for material: $330.99

A 4" main drain will run approximately $238.98 more in material than a 2" main drain and the problem for everything should be solved even for a 6" or 8" riser system. In my mind it beats adding 3 or 4 2 1/2" hose valves then having to drag hoses around to forward test for acceptance and every year thereafter.

$239 is a lot of money to us personally but on a 6" system covering 40,000 square feet it really is nothing to fred over. Matter of fact you would probably save close to that in labor it would take to lay out hoses for the acceptance test.

Labor to install might even cost less not having to drag a 300 machine out of the shop. In any event I really can't see it costing much more in labor.

Oh, and to the inspectors who seem to overly tighten 2" main drains with a wrench or channel locks this would save that little problem of teeth marks on the shaft.

Seems easy enough but am I missing something?