trav3501 Posted February 2, 2009 Share Posted February 2, 2009 The house I am staying in has low water pressure. There is a new large storage tank outside with a new pump. I was wondering what the max pressure is for the blue domestic water pipe. Link to comment Share on other sites More sharing options...
Boksida Posted February 2, 2009 Share Posted February 2, 2009 The house I am staying in has low water pressure. There is a new large storage tank outside with a new pump. I was wondering what the max pressure is for the blue domestic water pipe. See if you can find any writing on the PVC pipe. If there is something like Class 8.5 or 13.5, the number refers to the rated pressure in kg/sq.cm. Link to comment Share on other sites More sharing options...
skippybangkok Posted February 2, 2009 Share Posted February 2, 2009 (edited) Nothing like metal pipes ! My pumps are on a concrete slabs, which are slowly sinking as the ground settles......... in the process, its cracking the joints between the pump and the house....... Plastic has its limitations ! Edited February 2, 2009 by skippybangkok Link to comment Share on other sites More sharing options...
ShugNorris Posted February 2, 2009 Share Posted February 2, 2009 Plastic (PVC) piping is a lot easier to assemble, cheaper and less susceptible to corrosion so I'd say it's the better option. The pressure it can take depends on the diameter of the pipe. A little fresh water pump will only kick out a few bar... about 39psi?? and that will be more than sufficient pressure for the house. They will have operating pressures and a maximum bursting pressure which will be well outside the operating pressure. I'd imagine the house would use an inch diameter pipe or maybe 1.5 inch. Correct me if I'm wrong of course! Like Boksida said, check out some websites on companies selling PVC piping and some kind of plumbing site. Unless you've got a mega high pressure fresh water pump, you'll be fine! PVC piping is a lot more common now. Hope this helps, - Shug Link to comment Share on other sites More sharing options...
yabaaaa Posted February 2, 2009 Share Posted February 2, 2009 Plastic (PVC) piping is a lot easier to assemble, cheaper and less susceptible to corrosion so I'd say it's the better option. The pressure it can take depends on the diameter of the pipe. A little fresh water pump will only kick out a few bar... about 39psi?? and that will be more than sufficient pressure for the house. They will have operating pressures and a maximum bursting pressure which will be well outside the operating pressure.I'd imagine the house would use an inch diameter pipe or maybe 1.5 inch. Correct me if I'm wrong of course! Like Boksida said, check out some websites on companies selling PVC piping and some kind of plumbing site. Unless you've got a mega high pressure fresh water pump, you'll be fine! PVC piping is a lot more common now. Hope this helps, - Shug Long term durability of plastic? and more importantly the "O" rings inside joints? Ive seen a lot of pvc go crappy in 20 years are they made of pvc? easier to manouevre though and lightweight. Link to comment Share on other sites More sharing options...
LennyW Posted February 3, 2009 Share Posted February 3, 2009 - Shug Long term durability of plastic? and more importantly the "O" rings inside joints? Ive seen a lot of pvc go crappy in 20 years are they made of pvc? easier to manouevre though and lightweight. No O rings in the joints here, and the pvc will last a long time if not exposed to direct sunlight, long term exposure to sunlight tends to make it brittle. Most domestic pumps are set at 2.5 bar or less, provided you dont exceed that you will be fine. Link to comment Share on other sites More sharing options...
longball53098 Posted February 3, 2009 Share Posted February 3, 2009 The PVC pipe itself is not necessarily the problem here but the way they install the stuff. The gluing process is not so good when all the fittings are attached. They use cheap glue and no primer and I think many joints leak/burst way before the pipe's pressure rating is exceeded. Link to comment Share on other sites More sharing options...
yabaaaa Posted February 3, 2009 Share Posted February 3, 2009 The PVC pipe itself is not necessarily the problem here but the way they install the stuff. The gluing process is not so good when all the fittings are attached. They use cheap glue and no primer and I think many joints leak/burst way before the pipe's pressure rating is exceeded. Yes most important thing when doing any plumbing is getting joints spotlessly clean before assembly. Fail to do this and you are wasting your time. I like soldering copper it seems more permanent when I see the solder ring flow out no good underground though and needs plastic sleeve thru concrete too. Yes sunlight degrades the plastic. Link to comment Share on other sites More sharing options...
dotcom Posted February 3, 2009 Share Posted February 3, 2009 Actually you sandpaper the joints before gluing. Household pipes are 1/2 inch. Buy the heaviest 13.5 grade. The joints will come loose before the pipe splits. I use the glue that has an elephant on the box. Works well. As said above keep them out of sunlight. Link to comment Share on other sites More sharing options...
longball53098 Posted February 4, 2009 Share Posted February 4, 2009 You sandpaper the joints because? If a primer was available you would not need to sand them. Can anyone explain the pipe ratings? 8.5 is what in PSI 13 is what in PSI Link to comment Share on other sites More sharing options...
Boksida Posted February 4, 2009 Share Posted February 4, 2009 You sandpaper the joints because? If a primer was available you would not need to sand them.Can anyone explain the pipe ratings? 8.5 is what in PSI 13 is what in PSI Multiply by 14.22 and you won't be far off. Get more specifications here. Link to comment Share on other sites More sharing options...
mdechgan Posted February 4, 2009 Share Posted February 4, 2009 The lowest grade piping are rated well over 100 PSI. Max house pressure is no more than 50 PSI. Any more and one is only wasting pump energy. Most pumps shut off well under 40 PSI because of the pressure switch settings. Normal standard house pipe sizes and threads are: All fixtures are 1/2", most headers and runs are 3/4", water tanks and most good pumps use 1" pipes and threads. However most Japanese pumps like mitsu and hitachi are only 3/4" for their 150W pumps. Most failures are at the joints where the glue gets worn out. Its really cheap stuff, I think crazy glue is more stronger. Other failures are mostly do the stress points like pipes fixed to the house while others aren't. I had a problem with the waste lines because the waste lines and septic tanks sunk while the pipes didn't. I think the only way is to either install a flex hose or use longer runs with the pipes. Link to comment Share on other sites More sharing options...
dotcom Posted February 4, 2009 Share Posted February 4, 2009 Longball. Those numbers aren't pressure ratings. I am guessing it is wall thickness or something similar. Yes it is common in Thailand to sand the joints to get the glue to bond better. Buy the 13.5 grade - save yourself a lot of headaches. Link to comment Share on other sites More sharing options...
Boksida Posted February 4, 2009 Share Posted February 4, 2009 Longball. Those numbers aren't pressure ratings. I am guessing it is wall thickness or something similar. You are guessing wrong. The numbers are working pressure in kg/cm2 as mentioned previously in this thread. See Note 2 at the bottom of the attached spec. Link to comment Share on other sites More sharing options...
Crossy Posted February 4, 2009 Share Posted February 4, 2009 (edited) Handy-dandy metric conversion calculator (does pressure) here http://www.worldwidemetric.com/metcal.htm NOTE Volume conversions are for US units. 8.5 kg/cm2 is 121 PSI 13 kg/cm2 is 185 PSI These are working pressures, burst pressure will be significantly higher. Edited February 4, 2009 by Crossy 1 Link to comment Share on other sites More sharing options...
longball53098 Posted February 4, 2009 Share Posted February 4, 2009 As always you guys came through and provided the answers. Crossy that metric calculator did help and Boksida you are right on. I did look at the Thai Pipe sheet but since I cannot read Thai I never looked down at the notes. Dotcom thanks for the input also. This helps a great deal in my choosing the correct pip for my new build. Link to comment Share on other sites More sharing options...
dotcom Posted February 4, 2009 Share Posted February 4, 2009 As said before the joints will go long before the tubes. Link to comment Share on other sites More sharing options...
itsari Posted June 19, 2021 Share Posted June 19, 2021 On 2/2/2009 at 6:09 PM, skippybangkok said: Nothing like metal pipes ! My pumps are on a concrete slabs, which are slowly sinking as the ground settles......... in the process, its cracking the joints between the pump and the house....... Plastic has its limitations ! The foundations under the water tank supporting slab have limitations too Link to comment Share on other sites More sharing options...
Yellowtail Posted June 19, 2021 Share Posted June 19, 2021 I thing the glue here is great compared to the "safety" stuff they sell in the US. Link to comment Share on other sites More sharing options...
PJHassselt Posted June 19, 2021 Share Posted June 19, 2021 On 2/4/2009 at 10:05 AM, Crossy said: Handy-dandy metric conversion calculator (does pressure) here http://www.worldwidemetric.com/metcal.htm NOTE Volume conversions are for US units. 8.5 kg/cm2 is 121 PSI 13 kg/cm2 is 185 PSI These are working pressures, burst pressure will be significantly higher. On this forum we have the rule no other languages then English, and Thai are allowed. Probably we also must introduce the rule "no imperial units allowed" It is very, very confusing. Imperial is not scientific, so also not used by NASA. Most metric countries do not accept technical specifications in imperial units. Countries who use Imperial units use for electrical units Metrical units. (I never heard heard about 1/2V DC) Imperial units are very difficult to understand and to make calculations with. To cask to convert Bar to PSI is a stupid question. In metrical system when I see a tank, without needing a calculater I can estimate the volume it can hold, the weight from the fluid it can hold. This is close to impossible when using Imperial units. 1 Link to comment Share on other sites More sharing options...
Crossy Posted June 19, 2021 Share Posted June 19, 2021 7 hours ago, PJHassselt said: Probably we also must introduce the rule "no imperial units allowed" If you wish such a rule to be imposed please start a poll in the same way we do if someone suggests a new forum. Meanwhile since this is a 12 year old thread I'm going to close it unless someone has a really good reason to re-open. 1 Link to comment Share on other sites More sharing options...
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