tel Posted January 9, 2006 Report Share Posted January 9, 2006 can i have your advice please. tank is 1500x600x600. return inlet is hansen 25mm tank fitting. overflow is 40mm durso on 32mm tank fitting. (return is thru bottom of tank so tank can sit against wall) 1. should i go largest piping possible? (40mm piping has about the same internal dia as 32mm tank fitting and 32mm piping matches 25mm tank fitting in same regard) 2. should i use pressure piping?(i was considering hansen black piping which only comes in short lengths and uses a ''screw bayonet'' type joiner. 3. is standard pvc cement the safest/best? thanks :-? more basic questions to come......... Quote Link to comment Share on other sites More sharing options...
suphew Posted January 9, 2006 Report Share Posted January 9, 2006 1) yes, cost is not much more and you can always use reducers to attach to smaller pumps but you can't make the pipes larger, I used 32mm pressure plumbing I wouldn't suggest going any larger. The next size down is 25mm which is a lot smaller. 2) yes, go pressure piping, I never have problems sleeping at night. 3) yes. Quote Link to comment Share on other sites More sharing options...
chimera Posted January 9, 2006 Report Share Posted January 9, 2006 1. yes definately. 40mm down and you wont have any problems. that can handle heaps of flow. mine is t'd off to 25mm for the skimmer and remains at 40mm for the continuation of the pipe into the fuge 2. only required for the return. use 40mm drain pipe for down flow as its the cheapest stuff you can buy (and is never under any pressure anyway) its even cheaper than 25mm drain pipe! 3. yes but there are two types, non-pressure and pressure rated solvent. i use pressure rated for everything. Quote Link to comment Share on other sites More sharing options...
tel Posted January 10, 2006 Author Report Share Posted January 10, 2006 next doh question; whether to use rubber gaskets as are on tank fittings or not and how tight,too tight will squeeze all the silicon out??? told you theyd be basic but i dont wanna stuffup!! if you leave on rubber rings should you silicone between them and fitting?? Quote Link to comment Share on other sites More sharing options...
chimera Posted January 10, 2006 Report Share Posted January 10, 2006 next doh question; whether to use rubber gaskets as are on tank fittings or not and how tight,too tight will squeeze all the silicon out??? told you theyd be basic but i dont wanna stuffup!! if you leave on rubber rings should you silicone between them and fitting?? i used them, pies didnt so personal preference i guess. i would use them again but NOT by themselves. get your holes drilled oversize (not too tight but not too loose, say a 3mm either side) so you can fit a bead of silicon around them. i also rubbed silicon over my rubber gaskets too, seals them better plus they stick to the glass so you can get them just right position. dont overtighten them! you dont want the gasket squashed, only moderate pressure. remember once the silicon dries its as strong as the glass so its the silicon thats doing most of the work. i see the gasket more as a barrier to hold the silicon plus a backup seal (again, so long as you silicon around the gasket too) Quote Link to comment Share on other sites More sharing options...
tel Posted January 10, 2006 Author Report Share Posted January 10, 2006 thanks for your prev answer did you mean the gaskets are siliconed to fitting as well as tank?? Quote Link to comment Share on other sites More sharing options...
suphew Posted January 10, 2006 Report Share Posted January 10, 2006 I did mine the same as Pies, i.e. no rubber gaskets, I don't know that it makes any difference but the logic I used was that with the gaskets in there where 4 surfaces that could leak (either side of each gasket), maybe from movement or a bad seal etc, where as with just silicon there are only two. I don't see how adding the gasket adds any factor of safety when silicon is used in its place. To do it I put a bead of silicon round the edge of both sides of the hole, around the inside edge of the bulkhead where it touches the edge of the hole, and round the inside egde of the nut. When you screw it together the silicon will be forced to the outside edge creating a perfect seal every time. You can see that the seal is good because you will get silicon coming out from the bulkhead right round the whole edge. I did the nut up as tight as I was able to by hand. Quote Link to comment Share on other sites More sharing options...
slappers Posted January 10, 2006 Report Share Posted January 10, 2006 yep thats how i done mine to no worries yet Quote Link to comment Share on other sites More sharing options...
chimera Posted January 10, 2006 Report Share Posted January 10, 2006 thanks for your prev answer did you mean the gaskets are siliconed to fitting as well as tank?? yup both sides, smear a thin layer of silicon over both sides (much like putting a head gasket on a car) AS WELL as having the 'wad' of silicon around the thread of the tank valve (in the hole). lick ya finger and rub the excess silicon off (its not going to do anything anyway) and it also smooths it out. works a treat. silicon goes hard all around the gasket creating a wider seal than you could potentially otherwise get. I don't know that it makes any difference but the logic I used was that with the gaskets in there where 4 surfaces that could leak (either side of each gasket), maybe from movement or a bad seal etc, where as with just silicon there are only two. my gaskets dont move at all. not even the slightest amount. they are held firm once the silicon dries. you could get a bad seal with just silicon as well as a gasket - highly unlikely with either though. make sure there is no moisture in the hole so all the silicon sticks firmly to the glass and valve. I don't see how adding the gasket adds any factor of safety when silicon is used in its place so i wonder why the sell the gaskets with the valves in the first place? must be cheaper than providing a tube of silicon i guess my logic with the gasket is it creates a buffer between the glass (solid) and the tank valve (solid) By using only silicon, you have to be careful you dont over tighten the valve or its a possibility you squeeze out all the silicon creating a solid-solid join (or an air bubble which can cause movement) which is what you DONT want. so go mega more overboard on the silicon than under and wipe off what you dont need. who knows, i cant see any major negatives with either method. Quote Link to comment Share on other sites More sharing options...
Ira Posted January 10, 2006 Report Share Posted January 10, 2006 Most are probably intended to be removable, I doubt marine tanks are their intended usage. Using a gasket is far better for that than silicone. Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted January 10, 2006 Report Share Posted January 10, 2006 Plumber's rule of thumb: Double the diameter, get four times the flow. Quote Link to comment Share on other sites More sharing options...
chimera Posted January 10, 2006 Report Share Posted January 10, 2006 that's also a mathmeticians rule of thumb for the area of a circle: pi r^2 so much simpler Quote Link to comment Share on other sites More sharing options...
Brianemone Posted January 10, 2006 Report Share Posted January 10, 2006 its also my way of working out stuff. tank twice the size costs four times as much in jewelery for my wife's approval Quote Link to comment Share on other sites More sharing options...
tel Posted January 11, 2006 Author Report Share Posted January 11, 2006 drove all the way from howick to albany to plastic systems, well worth it. they had everything i needed, unlike anyone else i tried. i got sick of explaining to other plumbing suppliers what a union ball vave was. thanks for feed back, should be putting last coat on tonight and getting tank fittings installed. Quote Link to comment Share on other sites More sharing options...
chimera Posted January 11, 2006 Report Share Posted January 11, 2006 drove all the way from howick to albany to plastic systems, well worth it. they had everything i needed, unlike anyone else i tried. i got sick of explaining to other plumbing suppliers what a union ball vave was. thanks for feed back, should be putting last coat on tonight and getting tank fittings installed. should have gone to mico around the corner and got their discounts not alot in it though. i asked plastic systems for 25mm ball valve was last one left when i was there a week ago. told them i usually got mico discounts but they were closed, got ball valve for $30. cant remember if thats a good price or not. anyways you are right, plastic systems has EVERYTHING you can possibly imagine - massive warehouse of goodies i could run riot in there especially when i do plumb up my new tank :lol: Quote Link to comment Share on other sites More sharing options...
tel Posted January 20, 2006 Author Report Share Posted January 20, 2006 do you suggest using primer before cement? if so i need clear primer (pipe work in full view in lounge till cabinet fairy visits) which is like rocking horse sh#t to find!!! Quote Link to comment Share on other sites More sharing options...
chimera Posted January 20, 2006 Report Share Posted January 20, 2006 only if you use the american 'hot glue' stuff (the separate purple primer and red glue) - that stuff is AWESOME. however, after buying some and using it, i think just the usual pressure rated pvc solvent is fine. the hot glue stuff is evil and seals very well. but for our use, a little extra cost for not much advantage. just my 2 cents worth, an actual plumber might suggest otherwise! Quote Link to comment Share on other sites More sharing options...
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