Racinbob 11,062 #1 Posted November 1, 2022 (edited) This is really a question for plumbers out there. I do all my own plumbing and even get called on to help someone else but the bottom line is I'm an electrician. You know what they say about water and electricity.................. A couple weeks ago I replaced our bladder tank and all went well (pun intended) and my wife breathed a sigh of relief when I was done. Yesterday we were sitting there and all of a sudden we heard a bang and then a loud hissing noise. It was from the basement and before we could get down there the smoke/co detector was sounding and since it talks to one upstairs it was sounding as well. When I got down there water was spewing out and bullseyed the detector on the floor joists. Fortunately I added valves and I was able to get things shut down quickly. We got the worse of the water cleaned up and this is what I found: That fitting was connected to the brass tee coming out of the tank. It's a 1" FPT threaded onto the 1" MPT brass Tee. I run PVC up to where my new Pex piping starts. Here's my question. I know that plumbing threads are tapered. So as the fitting is tightened it puts outward pressure on the it. Would a professional plumber say never thread a female PVC fitting on a male metal fitting for that reason? Could it have been a fluke? Or did I just overtighten it causing excessive strain and doom it from the start? I couldn't wait for an answer yesterday cuz I needed to get our water back on so this if what I did: Fortunately our little town hardware store had what I needed. I threaded a 1" FPT ball valve directly to the tee. I cut out the PVC ball valve and reconnected things, starting with a 1" PVC male adaptor into the new ball valve. Now the PVC threads are on the inside of the brass fitting. Does my thinking have merit or did my gorilla strength bite me? In other words, did I just screw up and cause the failure? Edited November 1, 2022 by Racinbob Share this post Link to post Share on other sites
Racinbob 11,062 #2 Posted November 1, 2022 BTW. I'm declaring the smoke/co detector a total loss. It was filled with water. It might dry out and be just fine but I don't take chances in that department. 2 Share this post Link to post Share on other sites
ri702bill 8,316 #3 Posted November 1, 2022 NPT threads are by name tapered and act like a wedge when tightened. I assume the fitting broke at a parting line?? Not surprised. Years ago, I designed a custom ported Delrin grease dispensing head, per the customer's request and approval. Delrin is a laminate - two halves that habe a banana shape are bonded together to cancel each other out to get a straight part - until you tap it for a 1/8 NPT female thread on the parting line! It lasted 2 shifts until it split in two.... 2 Share this post Link to post Share on other sites
oldlineman 1,481 #4 Posted November 1, 2022 Not a plumber either, retired (Journeyman Lineman) although like you I do my own plumbing and help others also. Not sure about your first problem but your explanation makes sense to me, expanding pressure on plastic fitting in a brass fitting is probably the cause for the failure. Your replacement to me is a much better repair for the reasons you mentioned. I believe you will not have any more unexpected repairs on that tank. Bob 2 Share this post Link to post Share on other sites
squonk 41,076 #5 Posted November 1, 2022 Broke from overtightening looks to me. Probably stress cracked on install and just finally blew. At least you were home. This usually happens when you go on vacation , on a holiday or the middle of a night! If I ever have to thread a plastic piece into metal I try to go with schedule 80 plastic or tape the snot out of the threads and go light on the tightening 4 Share this post Link to post Share on other sites
Racinbob 11,062 #6 Posted November 1, 2022 34 minutes ago, oldlineman said: Not a plumber either, retired (Journeyman Lineman) although like you I do my own plumbing and help others also. Not sure about your first problem but your explanation makes sense to me, expanding pressure on plastic fitting in a brass fitting is probably the cause for the failure. Your replacement to me is a much better repair for the reasons you mentioned. I believe you will not have any more unexpected repairs on that tank. Bob My wife was sitting here and I told her what you mentioned and I was right about what happened. She asked me if you were a plumber. I told her no, retired electrician, and she just rolled her eyes. Oh, btw. The tank had to be replaced due to a ruptured bladder. It was original to the house making it 23 years old. In my opinion too small too. It was 20 gallons set up with a 30-50 psi switch. I went with a 36 and a 40-60. That's probably max for the pump and lift we have. 6 minutes ago, squonk said: Broke from overtightening looks to me. Probably stress cracked on install and just finally blew. At least you were home. This usually happens when you go on vacation , on a holiday or the middle of a night! If I ever have to thread a plastic piece into metal I try to go with schedule 80 plastic or tape the snot out of the threads and go light on the tightening Quite likely Mike but I won't tell my wife that. If it had to happen it sure picked the right time. We were sure lucky. I doubt it was blowing water for a minute but it sure was a lot of water, Fortunately no harm done. 1 1 Share this post Link to post Share on other sites
Jeff-C175 7,201 #7 Posted November 1, 2022 (edited) 21 minutes ago, squonk said: overtightening looks to me Me too. I've got the same setup, plastic female onto the tank tee. I've gotten into the habit of putting a hose clamp around the outside of the female fitting to give it a little more strength. I also use a plastic rated pipe dope, and ONE or TWO wraps of teflon on top of the dope. Too much teflon tape is IMO not a good thing because it 'cold flows' and the joint will loosen and leak over time. I might also think about adding some support under that horizontal piece in front of the tank, and some way to prevent that pipe from getting banged into if there's any 'traffic' in the vicinity. Old PVC gets brittle and it doesn't take much to snap it off. Edited November 1, 2022 by Jeff-C175 5 Share this post Link to post Share on other sites
oldlineman 1,481 #8 Posted November 1, 2022 She probably thinks we're sticking together since we both worked with electricity, but I really think you nailed it. Also Jeff has a good idea using the hose clamp for reinforcement. 1 1 Share this post Link to post Share on other sites
JoeM 7,873 #9 Posted November 1, 2022 I use this stuff for pipe threads and can be used with potable water to gasoline. Don't nearly have to tighten the fittings as much. Will not work on CPVC or ABS tho. 2 1 Share this post Link to post Share on other sites
JoeM 7,873 #10 Posted November 1, 2022 And if i do a plumbing job and nothing leaks.......I have overlooked something! 1 5 Share this post Link to post Share on other sites
953 nut 55,197 #11 Posted November 1, 2022 2 hours ago, oldlineman said: She probably thinks we're sticking together since we both worked with electricity, but I really think you nailed it. Also Jeff has a good idea using the hose clamp for reinforcement. I too am a former journeyman electrician who has been known to do a bit of plumbing. Got to agree, looks like it was over tightened. When I was healthy enough to volunteer with Habitat for Humanity I did all of their plumbing and electrical work under the license of a local contractor. Our local code on PVC was no more than one foot inside the house it had to transition to PEX, copper or galvanized steel pipe at a shutoff valve. Also had to have an outdoor shutoff valve two feet below ground in a NDS Box. Like @Joe M I have been using Rector Seal for years with great results. 2 1 Share this post Link to post Share on other sites
WHX?? 48,815 #12 Posted November 1, 2022 (edited) 5 hours ago, Racinbob said: cut out the PVC ball valve PVC valves were never my favorite. Year or three might not be able to operate. Truth be told Bob I think your first mistake was using pvc. In all my years I have never saw it used by the pros for water lines other than pools or lawn sprinklers. I prefer metal/brass period. Double that at the tank. Hate to say it but agree 100% with squonky. Was always sweat copper or press copper & pex in recent years. Press & pex just cause it's so darned quick. I never held a plumber's license but watched them and grilled them like a samich on jobs. Still have a few plumber pro friends and buy them beer to stay in their good graces. What say you Plunge? @JCM Edited November 1, 2022 by WHX?? 3 1 Share this post Link to post Share on other sites
lynnmor 7,305 #13 Posted November 1, 2022 30 minutes ago, WHX?? said: I prefer metal/brass period. Double that at the tank. My acidic water will take out copper or brass in just a couple of years. I went with stainless steel at the tank and CPVC for all the other lines. This is what worked for me. Share this post Link to post Share on other sites
JCM 9,132 #14 Posted November 2, 2022 Tough to beat type L copper with old school 95/5 or silvabrite soldered joints for longevity. Just my opinion. Thankfully no damage 3 1 Share this post Link to post Share on other sites
Racinbob 11,062 #15 Posted November 2, 2022 1 hour ago, WHX?? said: PVC valves were never my favorite. Year or three might not be able to operate. Truth be told Bob I think your first mistake was using pvc. In all my years I have never saw it used by the pros for water lines other than pools or lawn sprinklers. I prefer metal/brass period. Double that at the tank. Hate to say it but agree 100% with squonky. Was always sweat copper or press copper & pex in recent years. Press & pex just cause it's so darned quick. I never held a plumber's license but watched them and grilled them like a samich on jobs. Still have a few plumber pro friends and buy them beer to stay in their good graces. What say you Plunge? @JCM I agree. Not my favorite either but it was all pvc for over 20 years with no problem...............until I messed with it. The pvc only goes up to the floor joists where it's tied in to the all new pex piping which is by far my favorite. Our previous house was a combination of pvc, copper and iron pipe and a total mess. I completely replumbed it with pex using a manifold system. I loved it and the pex is electrician proof. This house was pvc coming i for 23 years and about like it is now but they switched to cpvc which is far too brittle and there was about 8000 fittings in the system. I tore out all the cpvc and plumbed back with pex with every fixture separately valved with lead free brass ball valves. I used all crimp fittings with 100% success except for a couple I failed to crimp. Copper has its own issues with the ground water here so I won't use that. If I have any more issues with the pvc it will be history and it all gets replaced with pex. 2 Share this post Link to post Share on other sites
Racinbob 11,062 #16 Posted November 2, 2022 49 minutes ago, lynnmor said: My acidic water will take out copper or brass in just a couple of years. I went with stainless steel at the tank and CPVC for all the other lines. This is what worked for me. I like that stainless tee. I didn't know they existed or I would have used one. 1 Share this post Link to post Share on other sites
WHX?? 48,815 #17 Posted November 2, 2022 What kinda beer you drink Plunge? 4 minutes ago, Racinbob said: couple I failed to crimp. Copper has its own issues Been ther done that Bob... 4 1 Share this post Link to post Share on other sites
squonk 41,076 #18 Posted November 2, 2022 (edited) Got called to an emergency job at a school. New Kitchen was going in. Refrigeration guy hadn't shown up in a week, walk in's weren't done and food was on it's way. School starting up in 4 days. So we get there. I do the cooler and my co-worker does the freezer. The plumbing is done but electric isn't finished and just small holding charges are in the system. The refrigeration guy used crimp style refer lines. I get the cooler up and running. Start picking up my stuff whilst the other guy is changing the freezer. All of a sudden BOOM!!! A line for the freezer in the ceiling wasn't crimped! Refer oil everywhere!!! Edited November 2, 2022 by squonk 1 Share this post Link to post Share on other sites
Racinbob 11,062 #19 Posted November 2, 2022 16 hours ago, Jeff-C175 said: Me too. I've got the same setup, plastic female onto the tank tee. I've gotten into the habit of putting a hose clamp around the outside of the female fitting to give it a little more strength. I also use a plastic rated pipe dope, and ONE or TWO wraps of teflon on top of the dope. Too much teflon tape is IMO not a good thing because it 'cold flows' and the joint will loosen and leak over time. I might also think about adding some support under that horizontal piece in front of the tank, and some way to prevent that pipe from getting banged into if there's any 'traffic' in the vicinity. Old PVC gets brittle and it doesn't take much to snap it off. Yea, I was looking at that and thinking the same thing. I also don't like the wiring that way. This was the 'let's just get the water back on' pictures. I'll put 2 supports under that pipe and run the wire down the wall. 2 Share this post Link to post Share on other sites
Racinbob 11,062 #20 Posted November 2, 2022 1 hour ago, squonk said: Got called to an emergency job at a school. New Kitchen was going in. Refrigeration guy hadn't shown up in a week, walk in's weren't done and food was on it's way. School starting up in 4 days. So we get there. I do the cooler and my co-worker does the freezer. The plumbing is done but electric isn't finished and just small holding charges are in the system. The refrigeration guy used crimp style refer lines. I get the cooler up and running. Start picking up my stuff whilst the other guy is changing the freezer. All of a sudden BOOM!!! A line for the freezer in the ceiling wasn't crimped! Refer oil everywhere!!! Hmmm, let me guess. That didn't dry up like my water did. 2 Share this post Link to post Share on other sites
953 nut 55,197 #21 Posted November 2, 2022 11 hours ago, JCM said: type L copper with old school 95/5 If installed properly as shown in @JCM's photos I would agree. The piping from the hot water boiler to the air handlers at my church was soldered copper pipe. One day we noticed some dampness on the floor of a storage room that has no plumbing to it. Thankfully this was in the summer and the boilers were not in use. We discovered that the installers had not removed the excess flux when the pipes were installed twenty years prior and the acid from the flux had eaten a pinhole in the pipe near the fitting. Further investigation showed several areas that were ready to go through. That was compounded by the installer hanging the pipe with galvanized steel wire which was also corroding the pipe. The replacement piping is also copper but the fittings are all "O" Ring Crimp connections. Pipes are all supported with plastic lined hangers like @JCM's and I feel this process is safer (our church is an older building with lots of dried wood floor joists) because on flames were needed to make the connections. 1 1 Share this post Link to post Share on other sites