Thread: Water pressure regulator

What year was the 80 PSI maximum water pressure standard come into existence?
I know it was in the 1998 ICC code book but I get this question when calling it out and a quick comeback with a year that it was established would be easier than explaining the whole new water tower and sub division theory.

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IPC developed first publ. 1995.





You'd have to go back to the contributory codes:

Uniform Plmbing Code (UPC) mainly in western U.S.

Standard Plumbing Code (SPC) adopted mainly in Southern U.S.

BOCA Plumbing Code (BOCA) adopted mainly in the eastern U.S

and also check:

CABO Plumbing Code (CABO) written exclusively for residential construction.

Boiler and water tank, pressure regulations, water softeners, etc.and predominance of copper tube in applications.

I recall 70 max psi at one time, but don't recall when that was or which code, or if was ANSI standard or AGA max static input for fuel-fired tank type water heating vessels of a lower btu rating. U/G to 80 may have been related to clean water/safe water acts and prohibitions using lead for potable water supply.

Perhaps we can find it by cross referencing for example the development of ANSI/ASSE 1003 (Performance standards water pressure reducing valve); the 70 or 80 static PSI may also relate to the development of the first combination pressure AND temperature reducing valves? or perhaps a pre-"www" (very old) "encylopedia of plumbing" or "health and sanitation" design guide.

I have a 1917 Ohio plumbing code book. It has a bit in there about not to exceed 80 PSI. Its mostly has to do with the velocity of the water in the pipes. To much pressure in the pipes will cause excessive water hammer and erode the pipes quicker.

My standard comment for high water pressure is that it can damage the fixtures and piping if it is not addressed. I have seen the bottom of urinals (actually three urinals side by side) blown out by high water pressure so it can be a potential problem.

Most if not all of the appliance manufacturers (dishwashers, clothes washers, refrigerators, water heaters, etc) list 80psi as the max water pressure in their installation manuals. Also, don't forget that once a PRV is added to a home the water supply becomes a closed system and you then need to add an expansion tank or expansion valve to take care of the pressure that will build up in the water heater from the water being heated! So you need to recommend a PRV and an expansion device when you find a home with high water pressure.

Originally Posted by Scott Patterson

... Also, don't forget that once a PRV is added to a home the water supply becomes a closed system and you then need to add an expansion tank or expansion valve to take care of the pressure that will build up in the water heater from the water being heated! So you need to recommend a PRV and an expansion device when you find a home with high water pressure.

That is not necessarily true!

There are a number of PRVs (Pressure Reducing Valves) produced with a THERMAL EXPANSION BYPASS!!!!

The standard thermal expansion bypass feature permits the flow of water back through the valve into the main when pressures, due to thermal expansion on the outlet side of the valve (such as those "backflowing" from the water heater) exceed those on the main supply.

A Watts brand LFN45B-MI (Lead free*) is one such PRV.

So truth is "it depends" on the system, the PRV installed, and the mains pressures. The presence of any PRV does not necessarily define the system as a "closed" one.

P2903.3.1 Maximum pressure. Maximum static pressure shall be 80 psi. When main pressure exceeds 80 psi, an approved pressure-reducing valve conforming to ASSE 1003 shall be installed on the domestic water branch main or riser at the connection to the water service pipe.

P2903.4 Thermal expansion. In addition to the required pressure relief valve, an approved device for thermal expansion control shall be installed on any water supply system utilizing storage water heating equipment whenever the building supply pressure exceeds the pressure-reducing valve setting or when any device, such as a pressure-reducing valve, backflow preventer or check valve, is installed that prevents pressure relief through the building supply...

In the instance of a PRV with an integral bypass, that PRV would BECOME the thermal expansion device, thus agreeing with both Scott and Mr. Watson.
Around here, there would be no way to verify the proper thermal expansion device integral to the PRV without digging since the PRV is always buried in the front yard and the valve box is almost always full of water or sediment.

I have this verbiage in my report when pressures in excess 80 psi are encountered:

The water pressure is too high. Modern standards call for a pressure regulator to be installed along with an associated expansion device in order to protect the building pipes and fixtures when the supply pressure exceeds 80 PSI.

Interesting to note is that there is no requirement for thermal expansion device unless there is a storage heater.

A Watts brand LFN45B-MI (Lead free*) is one such PRV.

I cut and pasted this model number into the Watts website and found no valve with that number. Perhaps you had another number in mind?

N45B Water Pressure Reducing Valves , Water Pressure Reducing Valves - Standard Capacity, Water Safety & Flow Control - Watts
This is model N45B and fits the bill. I did notice that if installed as their typical installation diagram suggest with separate check valve, the installation would be non-compliant since the check valve would prevent pressure from bleeding back to the main, negating the bypass feature of the PRV.

Originally Posted by Elliot Franson

I cut and pasted this model number into the Watts website and found no valve with that number. Perhaps you had another number in mind?

Because perhaps it isn't the catalog number it is a Series TYPE.

Navigate yourself to the Water Safety and Control Products Tab, then Select the Pressure Regulators option on the left menu.

It should bring you here: (clickable link to watts site): Pressure Regulators, Water Safety & Flow Control, Watts

Scroll down to the tenth (10th) ROW (near the bottom third of the page), note two entries on this row (out of three - the middle and the one to the right) are for TYPE LFN458 (size ranges). Click on the one that fits your main size - load THAT page with scripts and active X, next select the tab titled MODEL under the description and picture. Allow scripts and active X. YOU'LL SEE A LIST OF "Ordering Code" MODEL NUMBERS THEN.

Here is the specification sheet for the Series Type I referenced AS AN EXAMPLE (pdf file link from Watts site): http://media.wattswater.com/ES-LFN45B.pdf

Yes, I found it through that information. Interesting. Thank you.

J.L.

I respectfully disagree.

If you read my post completed prior to your comment, you will see I qualified it carefully. I believe you may have missed the nuances.

The installation you described as the only way it is done and the "always" condition found", again disagree, further must be accessible, additionally not burried IN EARTH, SILT, or submerged. "There is more than one way to skin a cat."

I suggest you review again the installation instructions, paying special attention to what is WRITTEN, all of it.

E.F.,

You're welcome.

Originally Posted by H.G. Watson, Sr.

J.L.

I respectfully disagree.

If you read my post completed prior to your comment, you will see I qualified it carefully. I believe you may have missed the nuances.

The installation you described as the only way it is done and the "always" condition found", again disagree, further must be accessible, additionally not burried IN EARTH, SILT, or submerged. "There is more than one way to skin a cat."

I suggest you review again the installation instructions, paying special attention to what is WRITTEN, all of it.

Disagree with what?
That the valves are always buried, or that almost always covered with water or silt?
Or that it is done this way in my area?
Or that both you and Scott were right?

Let me qualify further lest this digress into a needless pizzing contest.
IN MY EXPERIENCE, IN MY AREA, "I" have never been able to properly identify a PRV valve without digging.
Notice I never said it was right that they get covered with silt or water or that they are not readily accessible.

It is also my understanding of reading the code and the literature of the Watts company that the valve referred to by you and I contain an integral bypass that functions as a thermal expansion device.

Originally Posted by Jim Luttrall

Disagree with what?
That the valves are always buried, or that almost always covered with water or silt?
Or that it is done this way in my area?
Or that both you and Scott were right?

Let me qualify further lest this digress into a needless pizzing contest.
IN MY EXPERIENCE, IN MY AREA, "I" have never been able to properly identify a PRV valve without digging.
Notice I never said it was right that they get covered with silt or water or that they are not readily accessible.

It is also my understanding of reading the code and the literature of the Watts company that the valve referred to by you and I contain an integral bypass that functions as a thermal expansion device.

Or your characterization of how it should be installed, the device (and its function) or the limitations of a standard thermal bypass feature.

The presence of ANY pressure reducing valve in and of itself does not necessarily close the system. The overall system (and its componants), the supply (main, mains pressure, elevation, etc.) and the limitations of the device itself.

PRVs can be installed throughout the system. Whether or not they contain a standard thermal expansion bypass feature.

The presence of a PRV with a standard thermal expansion bypass feature does not necessarily ensure an open or non-closed system.

Safe residential systems contain certain redundancies in safety features, by design and necessity.

Sorry your thread took an unfortunate drift. I felt it was necessary to correct the erroneous generalization made earlier by S.P. I gave example as to how and why the generalization and advice by S.P. was incorrect in its conclusionary assumption that the mere presence of a pressure reducing valve/regulator in and of itself consituted a "closure" of a system.

Generally residential static water pressures are considered "high" at a much lower PSI than 80, even if higher pressure is desired at risers (example high ceiling multi-story residences) but is reduced at point of use or at branches on lower floors and/or basements. MOST appliances, water heating devices, etc. indicate a need to control, regulate, or reduce pressures to a control value below a max limit of 80 PSI. Generally the set-point is considerably lower than 70. I believe if you review the materials and warning labels on most "residential" TPRVs and water heating device "instructions" you will find references at the 70 PSI range for input. Many automatic dishwashers, automatic washing machines, and other devices with fast closing valves will indicate "recommended" significantly lower control thresholds for water pressure input than 80 PSI. Some pressure temperature reducing balancing valves also indicate lower static pressure values With more and more residences requiring sprinkler systems, finding a MAIN and solitary PRV at the curb box is becoming less and less common, especially in areas subject to freezing temperatures, rare would it be installed outside of the envelope of the home (and still be accessible, a requirement).

Has anyone ever seen a valve like Mr Watson is describing in residential construction?

I must say that I have not.

I'm sure they are used but why don't we see them? So my advice still holds true that if you see a PRV valve you will also need some type of expansion device, be it a valve or tank.

Originally Posted by Ron Hasil

I have a 1917 Ohio plumbing code book. It has a bit in there about not to exceed 80 PSI. Its mostly has to do with the velocity of the water in the pipes. To much pressure in the pipes will cause excessive water hammer and erode the pipes quicker.

Thanks Ron, that is a bit of useful information.

Originally Posted by Scott Patterson

Has anyone ever seen a valve like Mr Watson is describing in residential construction?

I must say that I have not.

I'm sure they are used but why don't we see them? So my advice still holds true that if you see a PRV valve you will also need some type of expansion device, be it a valve or tank.

I have never personally encountered one of these in a house, but I think that Mr. Watson was merely pointing out that these are a viable option. He may have also been alluding to the fact that generalizations are only good, if they prove to be true. Just my opinion.

Originally Posted by Elliot Franson

I have never personally encountered one of these in a house, but I think that Mr. Watson was merely pointing out that these are a viable option. He may have also been alluding to the fact that generalizations are only good, if they prove to be true. Just my opinion.

I agree 101%..... I had never heard of or seen that type of valve. You learn something every day..

I'm just curious if anyone has ever seen one in use??

Originally Posted by Scott Patterson

Has anyone ever seen a valve like Mr Watson is describing in residential construction?

I must say that I have not.

I'm sure they are used but why don't we see them? So my advice still holds true that if you see a PRV valve you will also need some type of expansion device, be it a valve or tank.

Yes.

Reducing on elevated (via tall risers) branches to remotely placed water heating devices as already indicated, and in existing construction in older developments fit with new water mains now with increased capacity and/or pressures, or in those areas "upstream" on the mains of newer developments, i.e. urban and sub-urban sprawling development - the existing homes on primary water service entrance, not previously or presently required to be "closed" is where I have encountered. Most often after the homeowner has had their TPRV replaced and still experienced "early morning dribble" syndrome - and it has been determined that at that time (wee hours in the morn) the urban/suburban system experiences slightly higher pressures (periods of lower or nearly non-existant consumption) than the water heating system (potable or non-potable) is designed for on input (70 psi static or significantly less such as some boilers).

How would you know that you have not encountered a PRV with thermal bypass? You'd have to had identified and reviewed the specifications on any PRV you encountered.

Originally Posted by Elliot Franson

...I think that Mr. Watson was merely pointing out that these are a viable option. He may have also been alluding to the fact that generalizations are only good, if they prove to be true...

Yes, and I thought I had said just that when I stated in an earlier post:

I felt it was necessary to correct the erroneous generalization made earlier by S.P. I gave example as to how and why the generalization and advice by S.P. was incorrect in its conclusionary assumption that the mere presence of a pressure reducing valve/regulator in and of itself consituted a "closure" of a system.

Originally Posted by H.G. Watson, Sr.

Yes, and I thought I had said just that when I stated in an earlier post:

I was only agreeing with you Mr. Watson.

I was wondering where and how you guys were verifying the water pressure.

Originally Posted by Alan C Grubb

I was wondering where and how you guys were verifying the water pressure.

Elliott, thank for the cute pic. I know how, what the intention of the comment was to find out where HI's where testing the water pressure. I have been told by several that they test on the hot water heater outlet which I do not agree with. Just wanted to see where others were testing.

Static pressure will be the same throughout the system. I test at the exterior hose bibs while testing the frost proof hose bibs.
BTW, the gauge from PE is much more reliable than the ones from local supply houses. Much heavier and larger to carry around, but better.

Originally Posted by Scott Patterson

I agree 101%..... I had never heard of or seen that type of valve. You learn something every day..

I'm just curious if anyone has ever seen one in use??

Scott, we have a subdivision going in with these types of PRV's going in.

BTW, the gauge from PE is much more reliable than the ones from local supply houses. Much heavier and larger to carry around, but better.

Mr. Luttrall has a point. It is also wise to purchase and use a gauge that is factory calibrated and can be recalibrated, to avoid arguments with omniscient plumbers and AHJs.

Originally Posted by Elliot Franson

Mr. Luttrall has a point. It is also wise to purchase and use a gauge that is factory calibrated and can be recalibrated, to avoid arguments with omniscient plumbers and AHJs.

Had to look that one up.....

om·nis·cient


–adjective 1. having complete or unlimited knowledge, awareness, or understanding; perceiving all things.



–noun 2. an omniscient being.

3. the Omniscient, God.

Originally Posted by Jim Luttrall

Static pressure will be the same throughout the system. I test at the exterior hose bibs while testing the frost proof hose bibs.
BTW, the gauge from PE is much more reliable than the ones from local supply houses. Much heavier and larger to carry around, but better.

That (highlighted and bolded) is NOT necessarily true.

That could be true in a COMPLETELY OPEN same sized loop and flat system with no use or activity precluding any check valves, booster pumps, intermediate PRVs, restrictions, increasers, traps, etc.

THINK about it. Where do you come up with this stuff?

Here is a thread on a plumbing forum you all should read about PRV's Water pressure too high after using hot water - RIDGID Plumbing Forum, Woodworking Forum, Power Tool Forum

Basically what the thread is about is a home owner noticed his water pressure spiking 10 minutes after he used the hot water. The PRV was set down to 50 PSI, when he took a reading after running cold water for 5 minutes it read 45 PSI, then when he ran the hot water for 5 minutes and shut it off it still read 45 PSI but 10 minutes later it spiked to 160 PSI

So of course the plumbers where telling him his T&P needed to be replaced since it was not tripping at the required 150 PSI, and they informed him he needs an expansion tank.

After some time of him listening to home depot employees and such and not doing as the forum members where telling him he still had the same problem. Once he installed the expansion tank, the problem went away.


Now I just gave you all the short and blunt part of that thread. The thread it self went on for 12 pages, and then the guy posted his final results on a new thread. Update on my Thermal Exapansion issue - RIDGID Plumbing Forum, Woodworking Forum, Power Tool Forum

As for thermal bypass built into these units, I remember reading somewhere they are not to be relied on, that an expansion tank is still required. I will look around and try to find what I read and get it posted here for all your reference.

Mr. Hasil:

Thanks for that post.

It all boils down to what we can see or not see.

If I see a PRV with out an expansion tank or valve, I'm going to recommend one or the other to be installed. I really do not know if that PRV is the type with a thermal bypass or not or if that bypass feature is working.

So, I will take the high road and go the extra mile by recommending the expansion tank of valve. What is the worse thing that could happen by me recommending this? I really can't think of a bad scenario for recommending it but I can think of several for not recommending an expansion tank or valve.

If the PRV is underground and I can't see it and the water pressure is OK, Most likely I'm not going to recommend an expansion tank. Now if I know that a TPR is underground, well you can figure it out....

It might be of interest that in Texas, the HI SOP requires an inspector to note the lack of an expansion tank in the presence of a pressure-reducing valve as a deficiency.

R.H.
There is more than one way to skin a cat.

There are other relief options to an exapnsion TANK (yet another device to water-log/fail).

Removing the heat-trap from the NIPPLE from the inlet of a storage type water heater is for example one way to have remediated, in an OPEN system.

Originally Posted by H.G. Watson, Sr.

R.H.
There is more than one way to skin a cat.

There are other relief options to an exapnsion TANK (yet another device to water-log/fail).

Removing the heat-trap from the NIPPLE from the inlet of a storage type water heater is for example one way to have remediated, in an OPEN system.

Mr Watson, the water heaters I have been installing do not have a heat-trap nipple. But lets just say there is a heat trap nipple as you say. Then why would the codes and the manufactures tell the installer to install the expansion tank on the cold side of the water heater?

For Illinois the expansion tank is the only acceptable way to deal with thermal expansion, unless it is a manufactured housing, then they can use a ballcock in a water closet that will handle the thermal expansion.

TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER r: WATER AND SEWAGE
PART 890 ILLINOIS PLUMBING CODE

SECTION 890.1130 PROTECTION OF POTABLE WATER

7) Closed water systems shall have a properly sized thermal expansion tank located in the cold water supply as near to the water heater as possible and with no shut-off valve or other device between the heater and the expansion tank. Exception: In existing buildings with a closed water system, a properly sized pressure relief valve may be substituted in place of a thermal expansion tank. For closed water systems created by backflow protection in manufactured housing, as required in Section 890.1140(i), a ballcock with a relief valve may be substituted for the thermal expansion tank.

Section 890.1140 Special Applications and Installations

i) Manufactured Housing and Mobile Home Units Manufactured Prior to June 15, 1976. At the time of water service connection, backflow protection must be installed between the water service line and any manufactured housing or mobile home unit that was manufactured prior to June 15, 1976. Backflow protection shall be provided by at least a dual check valve backflow preventer assembly (DuC) conforming to ANSI/ASSE 1024-1990. This backflow protection must be installed in all instances where a unit manufactured prior to June 15, 1976 is connected or re-connected to a water service line, e.g., for connection of a relocated unit, or re-connection of a unit that was disconnected to allow repairs to the water line; however, backflow protection is not required for existing units unless a new connection or re-connection to the water service line occurs.

Originally Posted by Ron Hasil

Mr Watson, the water heaters I have been installing do not have a heat-trap nipple. But lets just say there is a heat trap nipple as you say. Then why would the codes and the manufactures tell the installer to install the expansion tank on the cold side of the water heater?

For Illinois the expansion tank is the only acceptable way to deal with thermal expansion, unless it is a manufactured housing, then they can use a ballcock in a water closet that will handle the thermal expansion.

TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER r: WATER AND SEWAGE
PART 890 ILLINOIS PLUMBING CODE

SECTION 890.1130 PROTECTION OF POTABLE WATER

7) Closed water systems shall have a properly sized thermal expansion tank located in the cold water supply as near to the water heater as possible and with no shut-off valve or other device between the heater and the expansion tank. Exception: In existing buildings with a closed water system, a properly sized pressure relief valve may be substituted in place of a thermal expansion tank. For closed water systems created by backflow protection in manufactured housing, as required in Section 890.1140(i), a ballcock with a relief valve may be substituted for the thermal expansion tank.

Section 890.1140 Special Applications and Installations

i) Manufactured Housing and Mobile Home Units Manufactured Prior to June 15, 1976. At the time of water service connection, backflow protection must be installed between the water service line and any manufactured housing or mobile home unit that was manufactured prior to June 15, 1976. Backflow protection shall be provided by at least a dual check valve backflow preventer assembly (DuC) conforming to ANSI/ASSE 1024-1990. This backflow protection must be installed in all instances where a unit manufactured prior to June 15, 1976 is connected or re-connected to a water service line, e.g., for connection of a relocated unit, or re-connection of a unit that was disconnected to allow repairs to the water line; however, backflow protection is not required for existing units unless a new connection or re-connection to the water service line occurs.

R.H.

#1. You seem to keep missing (even with your own citations) CLOSED SYSTEM.

We were discussing an OPEN system, and MY POINT was that the mere presence of ANY PRV did not in and of itself indicate the system was a CLOSED SYSTEM as some PRVs do not CLOSE the system (bypass, etc.).

#2 Your "other forum discussion thread" offered was OFF TOPIC. The OP of that post clearly indicated the system was CLOSED just in from the METER (I.E. a whole house filter). Such filters and other treatment systems by design CLOSE the system.

the whole house filter I have near the meter in my basement burst.
I had a plumber come out to replace the broken filter system with a new one. He said while he was there, he noticed the pressure was a bit on the high side (70ish) and backed it down to 50 using the PRV

#3 the Illinois Plumbing Code does not require ALL residence plumbing systems connected to public or shared supply to be CLOSED. Your citations refer to those that ARE, HAVE BEEN, or WILL BE CLOSED.

#4 There are options to reduce thermal expansion and relieve pressures in a CLOSED system that do NOT include an "expansion tank", you just agreed with me regards to the watts governor, I disagree regarding your characterization that are the only options/methods permitted by the Illinois Plumbing Code.

#5 Please tell us which manufacturer's residential storage type WHs you do install. None come with factory installed heat traps in their nipples? Hmmm.

#6 I really don't see what the point of quoting a section having to do with CLOSING connections for pre 76 mobile or coach homes has to do with the topic thread. Yes they are/can be cross-connection, bacteria breeding, syphoning and contamination nightmares, even they aren't required to be retrofit with a CLOSING device that protects the supply system from contamination from them, unless there is a disconnection event that triggers it.

Breathe man, breathe.

Originally Posted by H.G. Watson, Sr.

R.H.

#1. You seem to keep missing (even with your own citations) CLOSED SYSTEM.

We were discussing an OPEN system, and MY POINT was that the mere presence of ANY PRV did not in and of itself indicate the system was a CLOSED SYSTEM as some PRVs do not CLOSE the system (bypass, etc.).

#2 Your "other forum discussion thread" offered was OFF TOPIC. The OP of that post clearly indicated the system was CLOSED just in from the METER (I.E. a whole house filter). Such filters and other treatment systems by design CLOSE the system.



#3 the Illinois Plumbing Code does not require ALL residence plumbing systems connected to public or shared supply are required to be CLOSED. Your citations refer to those that ARE, HAVE BEEN, or WILL BE CLOSED.

#4 There are options to reduce thermal expansion and relieve pressures in a CLOSED system that do NOT include an "expansion tank".

Breathe man, breathe.

Lol no problem Mr Watson, I am breathing just fine. Just wanted to point out code differences, just in case some one that is from Illinois comes across this thread and thinks they can use some other form to deal with thermal expansion on a closed system.

Here in Illinois there are no other options to reduce the thermal expansion in a closed system unless it meets the other stipulations in the code.

I did remember where I read about not relying on the thermal bypass in the PRV to deal with thermal expansion. It was my continued education class I am required to take every year to renew my plumbing license. And the reason for that is as you stated something else can make the system closed, like the water filter like you pointed out, but if you read all the posts (ignoring thread drift) he stated he had been running his new water filter in bypass mode, and he found out that the city has a backflow preventer at the meter yoke.

Originally Posted by H.G. Watson, Sr.

#5 Please tell us which manufacturer's residential storage type WHs you do install. None come with factory installed heat traps in their nipples? Hmmm.

Breathe man, breathe.

I think you are getting dielectric nipples mixed up as heat traps. I install Bradford White, State, and A.O. Smith water heaters.

Originally Posted by Ron Hasil

I think you are getting dielectric nipples mixed up as heat traps. I install Bradford White, State, and A.O. Smith water heaters.

Go back and read what I posted, you even quoted it, then mischaracterized what I said. I said remove the heat trap from the NIPPLE, and again I qualified it by saying from an otherwise OPEN system.

Furthermore, I am not the one confused. I believe you may be in your characterization that NONE NOW and NONE PAST A.O. Smith, Slate, or Bradford White Storage type Water Heaters (and again the topic was Residential) ship with heat traps in their nipples or integrally encorporated into them.

Actually, no I'm not, can be same area serving two purposes, the trap is inset. State and A.O.Smith, quite a few. BW it was my understanding they are always equiped with same from factory, used to be ball style (obstructive to flow in one direction), supposedly not so with new design new; parts to retro available. Take a look.

Here's an example (just grabbed the first one), note items 19 & 20 diagramed on page 1 and described on page 2.
A.O. Smith

http://www.hotwater.com/lit/partslists/PSD1293.pdf

Bradford White:

Bradford White | Heat Traps

In fact for most BWs it is the nipple trap (inlet and outlet) that provides the dielectric isolation to connect to the inlet or outlet nipple (old ball style and new disc style) for most units as shipped.

Note:

Available for both inlet and outlet fittings, the new design incorporates a flexible disk that helps prevent heat from traveling up into distribution piping without obstructing water flow. Unlike old ball-style heat traps, the potential for noise generation is eliminated by the flexible disk material design.

"Bradford White’s new heat traps are factory installed on all residential gas and electric models with 3/4" NPT top inlet and outlet water connections*. They are also offered for retrofit applications in a kit available from your Bradford White wholesaler."

Originally Posted by Ron Hasil

Lol no problem Mr Watson, I am breathing just fine. Just wanted to point out code differences, just in case some one that is from Illinois comes across this thread and thinks they can use some other form to deal with thermal expansion on a closed system.

Here in Illinois there are no other options to reduce the thermal expansion in a closed system unless it meets the other stipulations in the code.

which include in existing installations, a pressure relief valve.

I did remember where I read about not relying on the thermal bypass in the PRV to deal with thermal expansion. It was my continued education class I am required to take every year to renew my plumbing license. And the reason for that is as you stated something else can make the system closed, like the water filter like you pointed out,

Point being that the PRV with thermal bypass does not close the system, nor does the presence of ANY PRV indicate that the system is either open or closed (IOW if otherwise OPEN, a PRV with therma bypass doesn't create a closed system).

but if you read all the posts (ignoring thread drift) he stated he had been running his new water filter in bypass mode, and he found out that the city has a backflow preventer at the meter yoke.

Point being, that the exampled other-board's-thread(s) was/were not regarding an OTHERWISE OPEN system.

The muni or water authority having done same in Illinois would NOT BE THE NORM, but the exception.

Originally Posted by H.G. Watson, Sr.

Go back and read what I posted, you even quoted it, then mischaracterized what I said. I said remove the heat trap from the NIPPLE, and again I qualified it by saying from an otherwise OPEN system.

Furthermore, I am not the one confused. I believe you may be in your characterization that NONE NOW and NONE PAST A.O. Smith, Slate, or Bradford White Storage type Water Heaters (and again the topic was Residential) ship with heat traps in their nipples or integrally encorporated into them.

Actually, no I'm not, can be same area serving two purposes, the trap is inset. State and A.O.Smith, quite a few. BW it was my understanding they are always equiped with same from factory, used to be ball style (obstructive to flow in one direction), supposedly not so with new design new; parts to retro available. Take a look.

Here's an example (just grabbed the first one), note items 19 & 20 diagramed on page 1 and described on page 2.
A.O. Smith

http://www.hotwater.com/lit/partslists/PSD1293.pdf

Bradford White:

Bradford White | Heat Traps

In fact for most BWs it is the nipple trap (inlet and outlet) that provides the dielectric isolation to connect to the inlet or outlet nipple (old ball style and new disc style) for most units as shipped.

Note:

Available for both inlet and outlet fittings, the new design incorporates a flexible disk that helps prevent heat from traveling up into distribution piping without obstructing water flow. Unlike old ball-style heat traps, the potential for noise generation is eliminated by the flexible disk material design.

"Bradford White’s new heat traps are factory installed on all residential gas and electric models with 3/4" NPT top inlet and outlet water connections*. They are also offered for retrofit applications in a kit available from your Bradford White wholesaler."

I have a BW heater in the shop. When I go there I will snap a picture of the dieltric nipples on the unit and post them here. They do not have heat traps in them as pictured on their site.

I do recall A O Smith about 10 maybe longer years ago did include heat trap nipples, but had to many complaints. Last State heater I installed does not even come with nipples, it had female connections.