Need specs. for Galvanized Pipe Project

[Karl in NY]

I'm going to attempt building a DIY bubbler system to protect lake docks from ice damage...will use low-pressure (~6PSI), high volume air from a vane type air pump, probably one designed for an aerobic septic system that is designed for continuous-duty. I'm planning on a flushing port for each leg using 150PSI from a standard compressor for occasional flushing of debris that could eventually plug air holes.

My manifolds and submerged pipes will be galvanized, despite most commercial systems using poly pipe. I'm on a lake heavily infested with zebra mussels, which love poly pipe, but are repelled by zinc.
The submerged pipe laterals will be 1/2", installed just above the bottom on "legs" and "feet", to bring warmer water to the surface to eat the ice.

I need info. on how to specify the pipe and threaded fittings (LOTS of unions to permit disassembly of sections, and additions if the lake level drops in future years and the system needs to be extended.

Is typical galv. pipe equally galvanized on both the inside and outside? I need both to keep the mussels away. Are there different thicknesses of the hot-dipped zinc coating, or is it all the same? Also, there appears to be both seamed and seamless galv. pipe...any practical difference?

My preference is to avoid China-sourced pipe and fittings, due to poor experiences with black iron gas pipe in the past from that country.

Places like Home Depot are clueless about what they're even selling and cannot provide any specs. on their galv. pipe and fittings.

Your expertise and experience is needed.

 

[DonL]

Just look inside the pipe.

If you need to there are places that can galvanize pipe, to your specification.


Good Luck on your project.

 

[Sponsor]

 

[hj]

3/4" galvanized pipe is 3/4" galvanized pipe. It would be completely useless if it were NOT galvanized on the inside because THAT is where the water is. To be "seamless" it would have to be extruded and that would be an expensive process. Where the pipe is made is the important thing, not any of the other items you seem to be concerned with.

 

[Karl in NY]

So, can I assume that Asian-sourced pipe is a no-go?

With my project, there will be more water on the OUTSIDE of the pipe, since the interior is conveying air, not water, but will probably fill with water when the air pressure is not needed, hence I need zinc on both the ID and OD of the pipe and fittings. ZRC will be used for touch-up, like where bare threads are exposed, or where there are obvious scratches through the galvanizing.

Does anyone know whether either CO2 or CO gas pumped through the pipe occasionally will degrade the zinc galvanizing? It will be used to kill/release any mussels which have not been repelled by the zinc alone.

Also, anyone know if heavy wall galvanized electrical conduit has any advantages over galvanized water pipe? Seems to be same dimensions and threading.

 

[hj]

When the galvanize piping they do NOT consider whether the water will be inside or outside. It is dipped so the ENTIRE pipe is coated. WHY would electrical conduit be "better", because it should NEVER be immersed in water or have water inside it, and it only comes in 10' lengths so you need more couplings. BUY THE WATER PIPE AND INSTALL IT. As long as you do not run acid through it, the galvanizing should last as long as you need it.

 

[Karl in NY]

It is always assumed (under UL and NEC) that conduit will flood, hence the need for a "W" in the wire type designation (like THWN), indicating the need for waterproof wiring. I thought that UL/NEC specs might be more tightly enforced than plumbing specs.

Rigid galv. conduit is approved for both burial service and underwater service

 

[DonL]

It is always assumed (under UL and NEC) that conduit will flood, hence the need for a "W" in the wire type designation (like THWN), indicating the need for waterproof wiring. I thought that UL/NEC specs might be more tightly enforced than plumbing specs.

Rigid galv. conduit is approved for both burial service and underwater service

Look up ASTM.

http://en.wikipedia.org/wiki/ASTM_International


UL and NEC has nothing to do with water pipe, unless I missed something ?.

 

[Karl in NY]

Few/any local galv. pipe suppliers can produce evidence of conformance with ASTM B6/A385 and can't even certify country of origin. I recall the disaster well over a decade ago where black-iron natural gas pipe sourced from China caused many houses to either burn down, or to explode. This pre-dated the China sheetrock scandal.

With the black iron gas pipe, mostly drip-legs and their caps quickly developed rust perforations from inside (as did other fittings), and caused massive gas leaks. The "fix", was to gut it all and replace with materials that complied with the National Fuel Gas Code specs. I was lucky, all I lost that time was a barn, and no livestock. Litigation proved to be impossible, because no legitimate manufacturer's markings appeared on either the pipe or fittings...the markings were all of fictitious companies located in you-know-where, leaving people with nobody to sue except perhaps the wholesaler/retailer where the pipe was purchased, with really no way to prove it came from there, even with invoices and receipts, since the product was always listed generically, and never by the dummy maker's name.

But, once bitten, twice shy..

 

[hj]

The pipe has the country of origin listed along with its specifications on the outside of the pipe.

 

[DonL]

Around here the old school True Value hardware store has the good stuff.

And you will pay more for it.

 

[hj]

You will pay more even if it is NOT the good stuff.