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CI Rad, intlet & outlet setup - Bushings, nipples, elbows and TRV’s

HydronicRookie
HydronicRookie Member Posts: 54
Hi all, I’m in the process of organizing my purchases for a new hydronics system. We’re keeping the existing cast iron rads, all have inlet and outlet side-by-side on the lower edge of the rad. I'm looking to install TRV’s on each one, while running Pex-Al-Pex homerun from the basement.



My current dilemma is that most of the rads have bushings with ¾” openings that only accept counter-clockwise tightening nipples. That would be fine if I were using left/right nipples but I was hoping (perhaps foolishly) to connect the TVR tail-piece union directly into the rad/bushing, and although I haven’t actually held one in my hand yet, my guess is that they screw in “righty tighty” or clockwise.



Regarding this, my questions are: am I wrong to want to connect the TRV directly? And if not, do I have the wrong bushings? Perhaps, the TRV will be too close if I connect it directly, or is there another connecting piece that I don’t know about?





Once I resolve the rad-to-trv connection, I’d like to find a way to make the rest of the inlet/outlet configuration match the aesthetic of the old CI rads as possible – by that I mean, not having PEX above the floor-boards, possibly using a black iron riser or iron elbow. I was wondering , more generally, what your aesthetic choices are on the job when you guys are working with TRV’s and old cast-iron rads. For instance, do you install a matching modern-looking lockshield elbow on the outlet? Would you use iron over copper for ease of install , aesthetic or price?

Comments

  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    Radiator re-valving

    The radiator bushings will need to be changed to standard bushings so the tailpiece of the TRV can be installed on the radiator supply. We often use a 3/4" lockshield union connection on the return or use the existing radiator angle union. We pipe in black iron or copper from the TRV to below the floor and use a conversion fitting to connect to the distribution piping. Most radiators only require a 1/2" supply, but the "aesthetic" may look better in 3/4 or 1". If re-piping the distribution, any pipe size changes can happen below the floor.

    You'll need a large pipe wrench (3 ft.) to remove the radiator bushings and a special radiator spud wrench to install the TRV's. Spray the bushings with an oil penetrant (WD40) prior to removal. Sometimes the bushing needs to be heated to break loose.
  • icesailor
    icesailor Member Posts: 7,265
    Side By Side:

     "" Hi all, I’m in the process of organizing my purchases for a new hydronics system. We’re keeping the existing cast iron rads, all have inlet and outlet side-by-side on the lower edge of the rad. ""



    You need to post photos of what you describe as "Side By Side" and that some have opposite thread fittings. If they both the supply and return fittings are on the same end, you may have a very old type of radiator and you might not be able to do what you want in the way you want to. If you have the type of entry fitting, don't smash then out or destroy them. Someone will want them. They are extremely rare and not produced.

    Please post photos of what you are trying to do.
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    Good idea!

    Pics would be very useful!
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Gladly

    So here are the four different types of radiator we've got in the house; some have bushings, as you can see, and some don't. I've loosened the nipples off of each one using a pipe wrench and they all tighten counter-clockwise, whether straight into the rad or into a bushing. I haven't yet touched the bushings themselves, but I assume (for now) that they all tighten into the rads counter-clockwise as well.



    Paul you mentioned standard bushings - would these have a reverse (outer) male-thread and a regular (inner) female thread?



    Thanks for the piping tips, I'll probably opt for a black iron pipe and elbows, or lock shields if they look better next to the TRV and they aren't too costly. Is there any risk of galvanic corrosion say with the nickel-plated brass of a Danfoss valve?



    I will definitely hold onto the bushings if I don't end up using them, hopefully they don't give me a hard time in getting them off.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    edited June 2014
    More Pics Please!

    This I have not seen before. Could you take more pictures? Get the whole radiator in a pic. What does the other end look like? I wonder if one of those bushings has a dip tube that extends to the other end of the Rad?



    Harvey
  • HydronicRookie
    HydronicRookie Member Posts: 54
    edited June 2014
    Didn't think

    they were that unusual
  • bill nye_3
    bill nye_3 Member Posts: 307
    I wonder

    I wonder if the right and left hand thread was because the valve or fitting would not swing past the supply or return being so close together. You may have to draw them up simultaneously.



    Could you find or have some right-left thread nipples made up ?  Can you buy a left hand thread die ?
  • Canucker
    Canucker Member Posts: 722
    right/left nipples

    McMaster Carr has right/left nipples, I had buy a bunch when I picked up some old Corto rads from a house that had been built in 1917. Smallest length I could find was 4 inches. And nothing with 1 1/4 inch diameter, I'd have to make my own.I never found any bushings. All the rads in my house have the double connection on one end, just like the ones pictured.

    Harvey, none of the ones I've had apart appear to have any diptube in it. You can touch your fingers together inside(I was curious too) The thing that all of the rads in my own house have in common, is that they all came from old gravity fed systems. Could that be the reason they don't have separation between the intake/output ports?
    You can have it good, fast or cheap. Pick two
  • hot_rod
    hot_rod Member Posts: 22,022
    rebushing

    here are some old rad that I re-bushed for a homeowner. They came to me already sandblasted and powder coated.



    Some of the bushings I had to saw slot and collapse to remove them. I used stainless steel bushings and ss nipples to add the Caleffi TRV and lock shield valves.



    Both the TRV and lock shields have union connections, so all you need is to get the new nipples into the rads.



    Locktite 272 to "glue" the new bushings and nipples in.



    I built some pex adapter fittings also, but they decided to use copper stubs down thru floor, pex connected below.



    These were straight across piping, I connected one to the boiler in my shop to see how they would heat up. After a few hours the entire radiator was warm from bottom to top.



    I did drill and add 1/8 hygroscopic vents at the top also.



    It would be interesting to ,look inside those rads and see where the flow goes. I have a small Rigid See Snake that would reach inside to look around.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    edited June 2014
    R&L Nipples:

    Remember, a "Right & Left" Nipple can be used (and was) used as a union. That's why they are illegal in gas codes. In that case of the radiators shown, the valve is a union, the other uses a R&L nipple as a union. You can see them in old piping as a coupling and nipple. You just don't realize they are there.

    You'd be far better off (IMO) to use a quality Teflon Tape (like Blue Monster) and 100% Virgin Teflon pipe dope or Rectorseal #5. To allow for very minor movements. I never found a weeping thread that couldn't be resolved with judicious applications of Teflon Tape and quality thread sealants.

    Years ago, there was a guy going around taking 5 finger discounts by stealing installed submersible well pumps. He would put in a 1" piece of pipe and connect to the pit less adapter, pull the pump, cut it off, throw the poly, cables and pull rope back in the well and leave. It was a **** getting the remains out of the well. I lost three. I fixed his @$$ by putting a 4" nipple on the top of the pit less and a R&L coupling on the nipple. You needed a Left Hand nipple on a pull pipe to get it out. I never lost another pump. After a while, the guy went bankrupt. Then, went Toes Up from a Cocaine induced Myocardial Infarction in Boston.

    No one celebrated. I got calls for years about it.

    A guy's got to do what he has to do.



    http://www.plumbingsupply.com/leftright.html
  • icesailor
    icesailor Member Posts: 7,265
    R & L Nipples:

    Those Right & Left nipples are used as Unions.

    http://www.plumbingsupply.com/leftright.html
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Still befuddled...

    Hi, thanks for sharing that project. It resembles mine enough that it gives me hope that I'll find a decent enough solution to my current roadblock.



    In response:

    "Both the TRV and lock shields have union connections, so all you need is to get the new nipples into the rads."



    I'm hoping to get a better understanding of how exactly the nipples linked up with the TR valve.



    Forgive me for questioning your setup, but in the picture you provided of the Caleffi valve, it seems that the nipple is inserted at the bottom of the valve where I thought the riser connection should be. Isn't the radiator connection supposed to be in the direction where the arrow is pointing? Or have I got it backwards? Or maybe the valves can work both ways, which would be great!
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Will I still need

    some sort of coupling or union to join the nipple with the valve? If I have no other choice, then so be it, but I was hoping to have a more elegant connection.
  • bill nye_3
    bill nye_3 Member Posts: 307
    Can you

    Can you get a female union for the TRV ?
  • hot_rod
    hot_rod Member Posts: 22,022
    edited June 2014
    that valve is on the return side

    flow goes into valve with TRV head, thru radiator and returns out the lock shield.



    In your case it looks like this. The lock shield has a union, so thread the tailpiece into the rad with a radiator tool, (fits inside so you don't damage the chrome). then the nipple and valve on the other connection, connect the TRV head to either, probably want the TRV head to the front.



    The union tailpiece is a BSP, but into a 1/2 NPT Loctite's in just fine.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    Short Nipples:

    If you have access to a threading machine that cuts and threads nipples, or you know how to do it with nipple holders, take a 4" R&L nipple and cut it to the length you want the final nipple. Leaving the LH thread in place. Then, you can have a shorter R&L nipple. You still need a regular coupling. Unless you can get the radiator valve you want in a FPT configuration, you need the coupling.  Or else install the valve up side down or backwards.  Either way, you might be playing "Fun With Fittings".



    When you play with old stuff, or a customer wants to use old stuff, they might have to sacrifice beauty for functionality.
  • HydronicRookie
    HydronicRookie Member Posts: 54
    So I stopped by

    the supply shop and this is what we came up with. Its not pretty, but it should do the job I imagine.



    The nipple and coupling will likely be black iron, with some pipe dope and teflon they should all hold together nicely. Hopefully there won't be any galvanic corrosion in this setup.
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Thanks for

    the illustration, it makes much more sense now. By putting the TRV on the return side, I can make use of the female NPT at the bottom of the valve. It has the added value of having the sensor oriented horizontally and also takes up a lot less space than the 'side-mount' TRV model.



    Have you had any issues regulating temperature/flow from the return side? Are there any other things I need to take into account by doing this?



    I think I would prefer this to the coupling setup we arrived at the shop today.(picture attached).



    Thanks again for walking me through this.



    Now all I have to decide on is whether to have a lockshield or not. I'll be balancing the rads from manifolds, and don't aniticipate (hopefully) having to isolate or drain the rads individually once they're installed. Would I be fine with just a riser, elbow, and nipple on the supply side?
  • hot_rod
    hot_rod Member Posts: 22,022
    curious

    why you can't screw the valves tailpiece directly into the radiator without the additional nipple and coupling?



    Do you need to space the valve that far from the radiator?



    By the time you add the TRV head that assembly is way out in the weeds :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    Is that:?

    Is that a R&L nipple? That's what this all started with. If you don't need a R&L nipple, you only need the valve.

    I thought you said in the beginning that the radiator were tapped with left hand threads.
  • HydronicRookie
    HydronicRookie Member Posts: 54
    edited June 2014
    Indeed, left threaded Rads and bushings

    I'm sorry for the confusion, but I will still need the Left/Right nipple as all my Rad openings and bushings are left threaded.



    HotRod, not sure if you missed it, but I replied to your post directly up above - I think the setup you suggested is better than the one in the picture of my last post. I.e. placing the valve on the return and using the female NPT to engage with the nipple. It has several advantages, though I wonder if having the valve control connected to the return has any disadvantages?



    Also, I was wondering if you could suggest ways of linking the now downward pointing union connection to say a 3/4" riser pipe. I see in the picture provided, you fashioned a fitting to connect directly with PEX - I suppose I could connect it directly to PEX but if its not too much of a pain, I would like to have a riser out of pipe.



    IceSailor, yep since they're all left threaded I won't be able to use the tailpiece directly into the rad, unfortunately, so I'll be needing the Left/Right nipples one way or another - whether I employ the setup HotRod suggested on the return, or whether I use the coupling to link up the tailpiece with a Left/Right.
  • hot_rod
    hot_rod Member Posts: 22,022
    I see

    I thought you could replace the bushing and get them all to Rh NPT, but I see now some do not have bushings.



    Are they all 3/4" LH thread? I may have a work around with just a LH X RH nipple.



    Is copper an option for going down thru the floor? How many radiators total?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    R&L Nipples:

    In the normal installation of those old radiators, they were set back well away from the hole in the floor. Because the nipples are the union. That's why they were outlawed in gas piping. No nut to tighten. Can you get the TRV's as a straight FPTxFPT valve? The R&L nipple becomes the union. As I think about it, you really can't go much shorter on the nipple because you have to twist the nipple tight to make the connection. If you want to use those radiators, you have to use R&L nipples.



    Personally, I'd put those radiators in in a moment. I wonder is all your extra effort beyond that worth the effort. You will expend a lot of wasted time and energy talking to people who are clueless as to what you are talking about and what you are trying to do. And frankly, don't give a rat's. All those specialty valves like the TRV's you want, are all made overseas, out of the USA. They are designed for the metric system. They were never designed for US pipe systems. Anything you find is adapted to our piping. Europeans and the rest of the world love technology for technology's sake. Americans are CHEAP. If some GC's could get a 10 gallon electric water to provide enough hot water to heat a 5,000 Sq. Ft house and supply potable DHW for a 5 bathrooms with body spray showers for $100.00, that would be that. Any more, and someone is trying to screw them. Therefore, there's no market for what you are trying to do.

    Maybe somewhere on the Internet you can find a TRV that is straight through.  The photo with the two 3/4" pipe nipples connected to the 3/4" CXFPT adapters are connected to R&L nipples. Otherwise, they would have used copper adapters directly in to the radiators.

    It is said that in life, you can have ANYTHING you want, Just not EVERYTHING you want. Someone needs to decide what they are willing to live with and how much they are going to be willing to pay for it. I personally feel that TRV's on the floor are as useless as tits on a snake. How accurate can you control a room with the thermostat on the floor. There has to be better ways.

    IMO.

    The radiators are too cool for words though.
  • icesailor
    icesailor Member Posts: 7,265
    Supply Houses, Left Sided:

    See my earlier post at the end.

    Whomever you spoke to at the supply house who gave you that nipple, probably is clueless as to what a left hand thread, R&L nipple is. Or a R&L Coupling is. His only experience as a Righty was when he was taking a test and a Lefty sat to his right during the test and their writing arms conflicted for table space. Something the Lefty had experienced his whole life and understood, but the Righty was clueless about. Like always sitting in one of those Right hand school desks as a righty and not knowing what it was like for a Lefty to try to write on a RW desk. Lefty's will always try to take the left hand end of a table.

    My oldest daughter is a lefty. In school, she wrote as a lefty, and held the paper and wrote upside down and backwards. So, you could stand in front of the desk and read it. A teacher noticed it and wanted to send her for writing therapy because she wrote the wrong way. ****? She didn't smear the ink on the page with her hand as she wrote it.
  • hot_rod
    hot_rod Member Posts: 22,022
    true enough

    TRVs are a European product and method, millions of them are manufactured every year over there. They really are a nice, non-electric, proportional control valve. Much better control than a hand wheel :)



    I suspect the "look" of the device on a radiator is not quite what many US buyers enjoy. The control on the radiator does regulate just fine, plenty of electric baseboards with thermostats mounted on them in the USofA.



    Every TRV manufacturer that I know, and there are dozens of them, offer NPT versions. I believe Taco sold them for a time also, probably a high quality Italian import :)



    Below is a link to our international catalog, we have plenty of options, although not all are on the shelves in the US like WiFi enabled and Cv adjustable models.



    I think I can find a simple solution if you need. I enjoy a challenge, and like to see that old iron stay employeed.



    We also have an chain smoking, old timer machinest in Milwaukee that will build any adapter or thread you can imagine, he is always building custom parts for us. Really any true machinest can build a thread adapter, or custom nipple.



    Online you can find L X R nipples in a variety of sizes and lengths, so all you really need is the correct NPT sized valve, with at least one union connection to get them side by side on your rads.



    Looks like you have a variety of connection sizes. Are the large piped ones also LH thread?



    It's not all that hard to drill and re-tap a steel or iron connection, if some are 1/2" LH perhaps drill and tap to 3/4 npt, or 3/4 to1" if there is enough metal around the opening. Plenty of valve options with NPT.





    http://www.caleffi.com/international/en-int
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • HydronicRookie
    HydronicRookie Member Posts: 54
    edited June 2014
    Thanks for bearing with

    me here - I know this thread has gotten a bit lengthy and all for a seemingly simple problem.



    Here we go ...



    Out of 14 rads in my possession (...still need to source 2 more),



    7 have bushings with a 3/4" opening. Of these, all except 1 are left-threaded.



    The other 7 don't have bushings yet. 2 have 1-1/4" Rad openings, and 5 have 1" openings. All are left threaded. My intention was to fit them all with bushings going down to 3/4" openings to have a uniform valve size.



    It's occurred to me that acquiring bushings for these is not going to be cheap, but if there is no better way, so be it. I suppose I could use 1" TRV's for those 5 with the 1" opening, but that sized valve comes at a cost as well.



    I'm not opposed to using a copper riser into the floor if need be. I'll even join the Pex-Al-Pex to the valve if I have to. I was looking at Pex-Al-Pex compression fittings, and was wondering if they could possibly connect directly to the union side of the valve (though I doubt it, as they use r20 thread, and my guess the thread inside the valve union nut is npt).



    I'm happy to hear of any ideas on how to setup the riser, custom or off the shelf. Thanks again.
  • icesailor
    icesailor Member Posts: 7,265
    Nipples:

    I sent you a link to a source of nipples. Nothing is cheap. And if you want to dance, you have to pay the fiddler.

    I also told you that the R&L nipple is the union. Life and piping old things isn't perfect. You have to dance with who you brung.
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Potentially more trouble

    than its worth - I get what you're saying IceSailor. Its certainly starting to seem that way. I may very well be trying to fit a square peg into a round hole, but its worth a try to know for sure.



    I would like to think that the TRV's should work fine that close to the ground and that the designers took into account that possibility. But then again, I haven't tested any of these first hand so what do I know.



    You asked about a straight TRV vs. and angled one? They definitely are available, but how would that help?
  • HydronicRookie
    HydronicRookie Member Posts: 54
    nipple as union

    Thanks, and sorry for missing that. Definitely, if I turn the 'angled' TRV so that the female NPT is facing the rad, I can use a left/right nipple as a union.



    From there, I will have to figure out the riser part of it.
  • RobG
    RobG Member Posts: 1,850
    Tapping

    I would follow HR's advice and drill and tap for one size larger and be done with it. You could probably do them all in a couple of hours. They are rather unique so I would defiantly keep them. If you really wanted to get elaborate you could braze a piece of copper into one of the lines and extend it into the rad to promote a more even flow through the radiator.



    JMHO,

    Rob
  • hot_rod
    hot_rod Member Posts: 22,022
    edited June 2014
    LH on a budget

    You can buy the die segments from Ridgid and make your own nipples. You'll need a nipple tool to cut close nipples.



    If you don't own a Rigid die head, pawn shops and e-bay are inexpensive sources :)



    Or you can buy just the LH nipple without the coupling.



    Left Right Ron is a fellow I know that works in the solar industry. He invented and makes this LH/ Rh adapter for connecting 1/2 copper to tanks. Solder the bushing onto the 1/2" copper, thread into the tank and bushing at the same time. He asked us (Caleffi) to quote these for him. We really need to make 5000 pieces at a run to be affordable. Our robotic machines would spit one of those fittings out every 10 seconds. It's hard to re-tool a machine for 100 pieces, and 20 minutes work.



    You could buy these brass adapters from Ron and get all the 3/4 LH "holes" to 1/2" sweat. Then a compression style valve. Still may be too much $$



    May need to look at the budget first, be nice to use those rads with TRVs attached.



    Here is an example I built into a Duplex bushing to show how close you could build this if you had rh x lh nipples. This one happens to be 1/2, it's doable in 3/4.



    The other side of the valves could be copper compression, I know out 15mm will work with 1/2 copper.



    The 3/4 version would be 3/4 fip out the bottom.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    Straight & Level:

    "" You asked about a straight TRV vs. and angled one? They definitely are available, but how would that help? ""

    If it is IPSXIPS and no union, the nipple is the union.
  • icesailor
    icesailor Member Posts: 7,265
    Closer To Thee:

    When you locate a heating or cooling thermostat, do you mount it on the floor where it controls the floor temperature or in the area where you sit like 4 or 5 feet off the floor.

    http://www.oventrop-us.com/pdf/brochure/TRV_280807.pdf

    If you're really serious about all this, you might as well do it right. You need to accurately measure the output of the radiators using some equal factor for them ALL. Then, you have to do a really accurate heat loss for the rooms you want to use them in. We need balance in our lives. We need balance in our heating systems. You need to see if you can find a balance using the radiators you have in the rooms you want to use them in. I suggest not getting anal trying to make every room its own zone. It will cost a lot of time and materials. There are so many schemes you can use to do what you want. If you have rooms that are close together with similar needs, make them all one zone. Use the R&L nipples and whatever you need to make it work. If you are trying to connect the radiators with Home Runs with manifolds in a remote location, use zone valves on the manifolds and wireless thermostats located where they need to go.

    If you're serious about losing your rookie status, learn how to calculate your own heat loss. Its easy and you will never be sorry. The more you learn, the more you will know. Like Horseshoes & Hand Grenades, you only need to be close. Not exact. If this is for yourself, go for it. If it is for someone that wants it done by you, they need to understand that these things aren't cheap. But putting the thermostatic operators is really kind of tacky and a non starter for me.

    Keep us posted.
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Lots to think about

    Using TVR's on these rads might prove to be more trouble than its worth especially if in the end the sensor readings might be skewed so close to the floor. Another possible concern could be the high thermal mass of these rads making the TRV's constant adjustments irrelevant.



    I have started to shed my rookie status a bit - I've already done a room by room heat loss of the house - luckily they match up pretty well to the existing rads when using a 170˚ average water temperature. In light of these TRV travails, I'm now considering a more straight-forward floor-by-floor zoning with each floor/manifold getting its own circulator.



    Will definitely post with updates. Thanks for keeping me honest about what is reasonable given what I'm working with.
  • HydronicRookie
    HydronicRookie Member Posts: 54
    So the brass adapters

    would screw into a bushing and accept a right threaded tail-piece? Thats pretty cool. I'm sure I understood all of what Ron's innovation was, but does seem that it might be getting a bit expensive at this point to buy the extra adapter.



    I'm definitely keeping the rads but am now considering just zoning the three floors. Thanks for the help, will back again with updates.
  • icesailor
    icesailor Member Posts: 7,265
    Onions & Rookiedom:

    Let me peel away another layer of your rookiedom.

    The reason for doing the heat loss and the radiator output is to see how close you can get the radiation output into balance with the rooms. Which you did. If you picked a magic number and it was 170, and you can get radiators to equal what is needed to heat every room close to a set point with 170 degree water. So, you just learned how a gravity heating system works. If you pump water fast enough to keep every radiator filled with 170 degree water, all the rooms will be the same temperature. Therefore, if you use ODR/Out Door Reset you can lower the system temperature to evenly heat rooms with different temperatures as the OAT goes up and down. .

    Use either a ODR control or a 4-way valve that has ODR capabilities. Don't go nuts with circulators and end up over pumping it. Use zone valves. You can do a lot with your system and have a lot of fun learning while you do it.  

    If you understand what I'm saying.

    And the old dead wrench turners will be so proud of you.

    And you get bragging rights to go along with those old radiators that some can't wait to get rid of.