KGarten

Section P2803.6.1 #13 states that the discharge pipe "be constructed of those materials listed in section P2904.5 (water distribution pipe) or materials tested, rated and approved for such use in accordance with ASME A112.4.1" So no "regular" PVC allowed. The IPC 2003 commentary says "The discharge pipe must have a rating of 100psi at 180 degrees F. Even with this rating, the pipe may be suitable for the even higher temperature of 210 degrees F because the discharge pipe is open to the atmosphere. Water heater temperature relief valves are generally set to open at 210 degrees F."

Ya know, I've seen a few installations like that recently. So many joints in it they might as well have used Copper... Remember when the whole point of PEX was to have piping with as few joints as possible? Despite that, I don't see a lot of this stuff at all. Either it's just not very popular in my area or my kind of clients aren't buying those kind of houses. And I don't mind at all. What is really fun is when you really get into the technical aspects of pex installations that are like this (non manifold installations)with too many joints. For example: if you follow the installation in the picture from left to right and going up through the floor you have a total developed length just from the fittings of 40 feet. Each 90 degree turn in pex is a minimum of 9 feet developed length and a coupling or running tee is 2 feet. Also the interior diameter of pex is substantially smaller the copper. 1-1/2" Pex has the same internal diameter as 1-1/4" copper. And don't let them sell you on the "I can run it at a higher rate of flow" argument. The pressure loss at 7 ft/sec velocity on 4gpm on 1/2" pex is 20psi per 100'. Type L copper running 4gpm will run a velocity of 5ft/sec (which will be a quieter system) with a pressure loss of 10 psi per 100'. This is substantial when you consider the friction losses in pressure due to fittings (copper fittings add 1 foot developed length in 90s and 2 feet on branch tees . Couplings on small copper sizes are not counted at all.) It is easy for the Pex installations like the one shown in the picture to go into a higher range band in the IRC sizing charts. I've seen what should have been a 100' developed length design go into a 250' developed length because of fittings. The problems are worse in larger houses with bigger sizes of pex. I have been in a brand new 5000 sq/ft house where you could turn on a lavatory faucet and then turn on the one right next to it and watch both streams of water get smaller. And turn on the tub and watch the streams get smaller again. All the while the water pressure guage on the system is dropping 2psi, from 52psi down to 50psi. Anyone running a branch and tee system with multiple fittings using pex must substantially upsize the system or it will be noisy and inefficient at best. Manifold systems are the way to go.

http://contractormag.com/columns/yates/cm_column_260/ I think this article does a good job explaining the pros and cons of each type of installation. Too bad the diagrams mentioned in the article are not available (or I couldn't find them).

I respectfully disagree with Terry on never running a dual water heater system in series. My reasoning is that if the house is large enough to require two water heaters then they will be used roughly the same amount with the second tank in the series getting less use, but not enought to make an appreciable amount of difference in the lifespan between the two. I have also heard that if you run water heaters in parallel and the distance from the outlets of the heaters to where they connect together is not equal distance (or close to it) then water will be drawn unequally from among the tanks. Not being a engineer specializing in hydrodynamics I do not know if this is true or just an old plumber's tale.

I don't think that you will find any recommendations on water heater capacity to tub size because there are too many variables (gas vs electric / tank vs tankless vs the new hybrid systems). On conventional gas water heaters a 65 gallon or two 50 gallons in series or parallel would be best. A single tank-type water heater of 50 gallons or under will almost never be enough (unless they have an inline heater on the tub...another one of those variables). In my opinion this is where an appropriately sized tankless gas water heater shines. Always enough hot water to fill the tub without the static cost of heating a couple of tanks of water. BTW, the Kohler catalog that I have lists that most soaker tubs that would fit into a standard tub space have a capacity of about 50 to 70 gallons to the overflow. Deck mounted tubs that can potentially fit two people run about 120 gallons to the overflow. They do list one model as having a 170 gallon capacity (83" long by 64 1/2" wide.) called the Super Bath. Looks more like a wading pool to me.

I would say it is the plumber that would get the call. At least down here all things gas are (usually) the plumbers area of expertise. Most of the vent extensions I have seen are run out of soldered copper which ac guys don't play around with much, if at all. The utility guys will probably think you are nuts for even asking, in my experience. Once they install their basic items (meter, stops, etc) they are done. Might be different in your area, 'tho.

The International Fuel Gas code (2006) prohibits gas piping from being made out of cast iron (section 403.4.1) although fittings may be made from cast iron. ("Regular" metal gas pipe is steel or wrought iron). There are are number of exceptions to the fittings with bushings not being allowed (section 403.10.4 note 5.2). The code commentary states that "bushings have been known to split from over tightening." Also section 404.3 prohibits bushings of any material to be used in concealed locations, with the commentary stating the "split after assembly" reason. The National Fuel Gas Code (NFPA 54) has the same restrictions.

Sanitary tees are not allowed to be used in a horizontal to horizontal drainage configuration (IPC table 706.3). I don't think it being on a pump discharge line would make any difference. I'm not sure the pressure 90 (or quarter bend, if you like) should be used either. I would have also preferred the check valve installed on the horizontal pipe as it will be holding quite a head of water in a vertical installation.

I only get the rocks of despair at my house. I guess that's something else I'm doing wrong.[:-propell

Wrong choice of word on "distribution". My apologies.[:-ouch]

ABS is allowed for water service pipe by the IPC on table 605.3. My old UPC 97 code book has it listed in the Manditory Referenced Standards section under Water Service. As for the ABS turning story, I have no confirmation but I have dealt with certain pipes that will wilt in the sun (the one I am thinking of is a current type of acid waste piping system). I am certain that in the DFW area that I have not seen ABS pipe, cement or fittings at a supply house (much less an installation using it) in at least ten years. I don't know the reason, but it does not seem to be used down here anymore. And I agree that the pool installation mentioned in this thread is almost certainly not ABS.

ABS is code allowed for water distribution but it must have a marking on it designating that the pipe is pressure rated ("PR"). It will also have the NSF 61 marking on it. As to the ABS pipe itself, in this area (DFW) it is almost impossible to find ABS now. Apparently ABS was in use over 15 years ago, but was phased out because of problems with the heat down here. I was told by older plumbers that during summer it was frequently someone's job to go out and turn the ABS so that it would not bend from the heat while it was on the truck's rack. If the piping is ABS then you will have to find some abs to pvc cement. It will be specifically marked for this purpose (Hercules cement for this purpose has a brown label and says ABS/PVC cement). Check a plumbing supply store (not Home Depot or Lowes).

I believe that configuration would be acceptable matching the intent of the code. It would be a smoother connection and would reduce the potential of stop-ups in my opinion because you would not have to deal with the pipe size reduction caused by the baffle in a wye branch tailpiece.

IPC 802.1.6 Domestic dishwashing machines: "...or discharge into a wye branch fitting on the tailpiece of the kitchen sink or the dishwasher connection of a food waste grinder." Which means the connection must be made before the p-trap to prevent sewer gas from coming in this way.

I would check with the city water department and check if they are using meters with check valves. Many cities in this area have gone to this system to protect their water supply from back flow and back pressure. A water leak of "just" 2 or 3 gallons an hour would probably not cause enough system displacement for the meter to move; it would be more like just bleeding off pressure at first. Cities around here started meter change outs to this type about ten years ago. They do NOT notify residents of such a change in advance, generally speaking. This is also a good question to ask because if the system has the check valve at the meter the water heater now requires an expansion tank, as it is now a "closed system." If the system does not have the check valve the triangle (or other ounce meter) would definitely be a good gauge of a leak.