backflow needed with auto feeder

Bob Harper

you must have backflow protection anytime you use potable water for non-potable uses such as a boiler. There must be isolation valves for servicing. It must be accessible.

Just because a code isn't enforced on inspections doesn't negate the code and just because something isn't in the codes doesn't mean you don't have to do it. Codes are minmum performance--professionals are maximum performance.

Tim_67

backflow needed?

Do you need to install a backflow prevention device on the water feed line to a residential steam boiler? There will be an autofeeder on the line which I assume would be sufficient protection. If it is not, could someone reccomend a device to use upstream of the autofeeder?

Norm Harvey

What state Tim?

I have never had a problem during inspection of my installs in MA not installing a backflow with an auto feeder. I agree with you, common sense says the solenoid is shut just like a valve all the time it is not actively feeding.


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Tim_67

That's what I figured, seems safe enough to me, maybe I am just overthinking it?

nicholas bonham-carter

common sence and the code

i am not against them in general, but codes sometimes seem written by and for people WITHOUT common sence.
i had a manual shut off AND a spring loaded valve on my gravity steam system [no aut-fill]. it still irks me that i needed a backflow whose cost seems excessive and needs yearly pricey inspections.
what possible combination of events could possibly occur to enable accidental cross contamination between boiler and drinking water system [and how likely are they to happen]? --nbc

Timco

Here in UT residential systems require a single check, and commercial systems a double check, and they never get a simple filter in front of them so they always get a tiny piece of rust or debris on the soft rubber washer. In a pinch, I have flipped the washer over until I can get to the supply house. There used to be a 'backflow prevention' link in the library that had dozens of cases of people getting sick where no backflow prevention was used or it was done wrong. I can see where an auto fill on a HW boiler leaves some connection between the two, but not on a closed solinoid.

Tim

Bob Bona_4

have to

have it by code. The feeder cannot be relied on to keep things going one way.

Watts, Conbraco, and others make stand alone BF preventers.

Edward A. (Ed) Carey_3

Yes, it is needed

Bob H and Bob B are correct. Backflow prevention is needed.

When you are thinking of the auto feed solenoid doing the job, I think you are limiting your thought to the boiler and domestic system both operating properly.

Think about this.

The domestic water supply goes down, (water main break down the street, well pump failure, HO shuts it off to work on plumbing pipes, whatever).

Someone in the home flushes a toilet, or runs water. Now the DW lines in the home are no longer pressurized.

The boiler is running and making steam. Water level drops and the solenoid opens to add water. However, there is no water, and the DW lines are not pressurized.

The water feed line is obviously (or should be) entering the heating system below the boiler water level. So the higher pressure in the boiler, can push heating system water backwards through the open solenoid, into the un pressurized DW pipes.

Later, the DW is restored to the building, and the next time someone runs the DW they get a slug of boiler water before the pipe clears.

If they left a valve in a sink open, or the commode did not fill, the DW system would not be sealed and a considerable amount of boiler water could enter the DW pipes.

All you really need is a water flow interruption for any reason, combined with the boiler running and attempting to add feed water during the run cycle.

Ed Carey

Norm Harvey

I've never seen a steam system in MA with a backflow. It looks as though I'll have a lot of 'splainin to do when people ask me why I'm putting them on now.

Thanks for the lesson.

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frankiewrench

BFP

In NYC not only is a back flow preventor required, but also a check valve installed closest to the boiler, then the manual/auto/prv valves, then the BFP. A Watts 9D for up to 350,000 input, and other devices for larger loads.

Dry Steam

NY State requires them on all boiler systems that are served by municipal water systems.

Edward A. (Ed) Carey_3

Municipal vs well pump

Scott,

I am aware of NY State regs as you said, and I have heard of other places having regs like that for only municipal water systems in the past. Many times those regs are silent regarding well pumps. I always wondered what the logic of that was.

If a person has a well or city water, and the DW goes down, the result of the cross feed to the DW from the boiler would essentially be the same within that house.

However the condition is actually much more likely to occur with a well. In many areas power interruptions in the winter due to storms (in the heating season) are a frequent occurrence. Then the wheels are set in motion for a problem.

When the power goes off you would not normally loose municipal DW. However if the electric goes off with a well pump, your pump also goes down. Once you have used up the small water reserve in the pressure tank, the DW pipes are no longer pressurized and the problems start.

Ed Carey

Dry Steam

I agree Ed

Ed,

I agree with you, Just wait I'm sure they will come up with something. "The DOH", like to constantly reinforce their regs and laws on everyone. Their regs apply to any public water system.. Meaning Community Water System CWS, Noncommunity Water Systems NCWS, Nontransient Noncommunity Water Systems NTNC, and Transient Noncommunity Water Systems TNCWS.

A public water system definition in NY is any system with at least 5 service connections or that regularly serves an average of at least 25 people daily for at least 60 days out of the year is considered a public water system.

Taken directly from NYS Public Health Law, Section 225 Part 5, Subpart 5-1 Public Water Systems.

5-1.31 Cross connection control. (Effective Date: Dec.30, 1992)

The supplier of water shall protect the public water system by containing potential contamination within the premises of the user in the following manner:
by requiring an approved air gap, reduced pressure zone device, double check valve assembly or equivalent protective device consistent with the degree of hazard posed by any service connection;
by requiring the users of such connections to submit plans for the installation of protective devices to the supplier of water and/or the State for approval; and
by assuring that all protective devices be tested at least annually. Records of such shall be made available to and maintained by the supplier of water. Such tests shall be conducted by certified backflow-prevention device testers pursuant to the following requirements:
a "general tester" certification will be issued when the applicant presents proof of satisfactory completion of a training course for testers of backflow-prevention devices which has been approved by the department.
a "limited tester" certification will be issued when the applicant presents proof of employment by a manufacturer as its agent for the servicing, maintaining and testing of backflow-prevention devices.
the department has the authority to require any person applying for certification or renewal of certification as a certified tester of backflow-prevention devices to take a written, oral or practical examination, if it deems such examinations to be reasonably necessary in determining the applicant's qualifications. The results of such examinations may be the sole basis for approval or disapproval of an application for certification or renewal of certification.
at least three months before the expiration date of a current certificate, both a general tester and a limited tester must submit proof that they are still engaged in the activity represented by their current certification.
a certification will be suspended or revoked, on due notice and an opportunity for a hearing thereon, for any of following reasons: submission of false test reports for backflow-prevention devices; proof that the person is no longer engaged in servicing, maintaining and testing backflow-prevention devices; or failure to apply for recertification.
The supplier of water should not allow a user to establish a separate source of water. However, if the user justifies the need for a separate source of water, the supplier of water shall protect the public water system from a user who has a separate source of water and does not pose a hazard as detailed in subdivision (a) of this section in the following manner:
by requiring the user to regularly examine the separate water source as to its quality;
by approving the use of only those separate water sources which are properly developed, constructed, protected and found to meet the requirements of sections 5-1.51 and 5-1.52 of this Subpart; and
by filing such approvals with the State annually.
All users of a public water system shall prevent cross-connections between the potable water piping system and any other piping system within the premises.
Any installation, service, maintenance, testing, repair or modification of a backflow prevention device shall be performed in accordance with the provision of any county, city, town or village having a plumbing code. For this section, a backflow prevention device is an approved air gap, reduced pressure zone device, double check valve assembly or equivalent protection device designed to prevent or contain potential contamination of a public water system. All individuals who perform testing of backflow prevention devices shall be certified, in accordance with paragraph (a)(3) of this section.

The federal definition of a public water system refers to a system that serves 15 or more service connections or serves 25 or more persons daily for at least 60 days out of the year.

The caveat being "All users of a public water system shall prevent cross-connections between the potable water piping system and any other piping system within the premises."


Soooo I thought this might interest someone if you were so inclined to be bored this afternoon. :{)

Edward A. (Ed) Carey_3

WoW

Hey Scott,

I said I was aware of it; however I never actually read it in print until here.

WoW

That sure looks like some bureaucrat had to give his brother in law a job, and decided to tell the brother in law to write a regulation regarding water quality.

It would probably taker longer to read that than it would to install a BFP on the line.

(;0

Thanks

Ed Carey

Rich Kontny_3

Exposure

Codes are there for a reason guys. I would not want to in this day and age install any potentially hazardous heating device that can and has contaminated potable water lines!

What part of exposure and liabilty don't you understand??

Steam can create a vacuum and pressure situaion in one runaway firing!

Hate to be so firm but this is a no brainer! A Watts 9-D or equivalent on no chemical systems and a minimum 1/2" 909 Series on systems with chemicals! Code is always superceded by logic and common sense!