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Old 19-08-2013, 21:44   #31
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Re: Raw water pump. You can't get there from here

I apologize. I just saw Sailorchic's excellent piece on bronze vs brass.

I try and stay away from the UNS (Universal Numbering system for Ferrous Metals) like calling red brass C23000. If you did the same for leaded red brass you'll be looking at half a dozen numbers (from C836000 on) and then there's the difference between ASTM B62 and ASTM B505. Both are leaded red brass but one is cast (B62) and the other is extruded (B505) and both are 85% copper, 5% each of lead, tin and zinc.

I was talking to an Apollo engineer about the makeup of their flanged sea valve, and he said it had some brass in it. He then proceeded to tell me that it had a brass stem and ball, because they were made of B505 brass. I'm not a metals expert, but it conflicted with all the information I seen. He simply had it in his head that the sand cast components (B62) were 85-5-5-5 bronze and the stem and ball (B505) were 85-5-5-5 brass when the only difference is how the metal is formed.
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Old 19-08-2013, 22:33   #32
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Re: Raw water pump. You can't get there from here

One note, as per Hopcar's check with his supplier and the strict no-lead requirements in plumbing valves and fittings in current building codes, I think you will find that a lot of the 85,5,5,5 bronze will be using aluminum instead of lead now a days. Not so much in seacocks but in the NPT fittings and valves.

The difference is now you have 10% sacrificial metal in the casting (5% zinc and 5% aluminum) where before only the zinc had a high galvanic voltage potential. But its only 10 percent of the metal so not a major problem structural wise.

Yes there is not a true standard in when you have brass and bronze as many ASTM numbers tend to flip flop weather its bronze or brass. Something about too many cooks I think.

But the general consensus is anything 77% to 87% copper is bronze and anything less then 77% is brass. So despite with the code committees call it, 85,5,5,5 is bronze. Though to me anything below 80% is brass. But I'm picky.

Of course then you get into the whole issue of something stamped with an ASTM number not actually meeting that standard. That is a problem with some pipe, fittings from a large asia country. Seen it first hand.
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Old 20-08-2013, 00:32   #33
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Re: Raw water pump. You can't get there from here

Hi again Sailorchic34,

Did not read all the posts so I am not sure what is previously stated here. However you appear to be discussing going from 1 1/4" NPT on your strainer to 1/2" hose tail.

I would not make life too complicated with an extensive metallurgical survey and analysis but look at what you are going to clamp onto the hose tail---plastic hose?

If this is the case a black poly reducer and standard brass or SS hose tail is probably going to be much more durable than the hose attached to it.
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Old 20-08-2013, 07:05   #34
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Re: Raw water pump. You can't get there from here

I want to again thank Sailorchic for pointing out that 85-5-5-5 may not be exactly what we assume it is. Aluminum does not turn into lead, anymore than lead can turn into gold. And even though its only 5%, I'd at least like to be able to make an informed buying decision. Thanks again.

RaymondR - Your "black poly reducer and standard brass or SS hose tail" comment is an interesting one. It is probably the one and only situation where it would make sense that the hose would be the weakest link. I assume your referring to a bushing reducer where the male thread of the reducer screws into the female bronze and the bronze male threaded tailpiece screws into the female bushing. This is the only case, that I can think of, where the PP is used as a filler and the bulk of the strength is the mating of the male/female parts. That would possibly be the only case where the PP would outlast the hose.

I did some impact testing on this topic. I first tested a 1 1/2" bronze tailpiece for impact it survived 7 hits, so let's give that a value of 1. I then tested other tailpieces and hoses. PVC Schedule 80 would a -6 on the scale. one hit and it was gone. A Forespar Marelon tailpiece was a -5. I had one plastic tailpiece that sustained 18 hits before breaking or a +11 on the scale. Onto each tailpiece I added a small section of hose. The least durable hose I tested was a Shields reinforced white vinyl waste hose. it took 10 hits or a +3 to finally cut through it. The cut was right where the barbed section ended.

A non-glass PP tailpiece would be a -6 (PVC range) and a 30% glass filled PP tailpiece would also be a -6 or possibly a -5.

I didn't try the nylon reinforced clear vinyl hose. My guess is that it might be a -4 or -3.

The issue is shear. Hose is flexible and a fitting is fixed.

Hope this helps.
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Old 20-08-2013, 17:48   #35
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Re: Raw water pump. You can't get there from here

To eliminate the need stack up a bunch of bushings to get to the size you need you could use a reducing coupling and a short nipple.
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