I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

I used Scd 80 PVC to construct a seawater manifold exactly as you describe
for Swee****er -- 2" top quality seacock and then hose and Scd 80 from
there.


----

However, first I should say that a Dogpile search on "bronze pipe" came up
with several suppliers such as

Farmer's Copper & Industrial Supply, Inc.
P.O. Box 2649
Galveston, TX 77553-2649
USA
Tel: 800-231-9450
Fax: 409-765-7115
Product Description
Inventories C65100 Silicon Bronze Pipe From 1/2"
To 6" Schedule 80 & C65500 Silicon Bronze
Welded Pipe To Specifications

Once you had Silicon Bronze pipe, making nipples is a PIA, but no sweat.
West claims that its Apollo ball valves have Stainless Handles and you could
always fab new handles for the Conbraco valves from 316.

And, of course, our favorite industrial supplier will be happy to sell you
either 304 or 316 fittings for a price. I would probably be OK with 316
(maybe even 304) for cold seawater.

Finally, there's galvanized steel. Fintry's piping maze (see
http://www.mvfintry.com/pix/piping800.png) is mostly galvanized steel. Most
of it is thirty years old and has passed a rigorous survey recently. Some
was replaced in her refit in 1998. The only thing about that makes it
difficult to duplicate is that it's all welded lengths, with four bolt
flanges at every valve and coupling (tees and wyes are welded). There are
no threaded connections. Steel fails softly and slowly -- you get a weep
and then, if you ignore it, six months later you have a problem. You'd want
Scd 80 here, not for strength, but for more material to rust before failure.

Scd 80 Issues:
1) the Scd 80 will burn. On a boat with a lot of seawater hose below the
waterline, this isn't an issue, because the hose will burn anyway (and so
will the hull, in a glass or wood boat) -- but on Fintry, all below w/l
seawater is in pipe so that if we have an engine room fire, we can (it says
in the manual) shut off the air vents, pop the foam, and wait for it to go
out, without worrying about sinking the boat. ("all" isn't quite true --
there are some on-engine hoses, but I hope those will boil for a while
before burning through)
2) Scd 80 is more fragile than metal valves with hose. On Swee****er, the
manifold was stuffed between two floors and thoroughly protected. I'm
pretty sure you could jump on a Scd 80 manifold without damage, but its
protection would need care.
3) there are a few fittings that are very hard to source in Scd 80 (I don't
remember what, but only that there was one white piece -- a barbed nipple I
think).
4) There are surveyors who will hate it. We had Swee****er surveyed by a
tough old guy (gone now) just before the trip (insurance company insisted,
but it's a good idea to have an independent check on your work) and he was
happy with it (I had checked with him before we did it). If you are
insuring, then figure out who will do the survey after launch, and ask him
or her.
5) On the other hand, a lot of big boats use Scd 40 pvc for internal
piping -- not seawater, but things like sewage, and surveyors are OK with
that (stinking is OK, sinking is not?).
6) A lot of the bits and pieces we put on Swee****er had Scd 40 PVC --
fittings for air con, watermaker, refrigeration seawater -- all "good"
brands.

Jim Woodward
www.mvFintry.com


"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...
I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

A hardware store near me carries what they claim are bronze pipe nipples.
They are dark, not like yellow brass, except where they are threaded. I used
one to mount an aqualarm next to a strainer. I wish I could figure out how
to verify that, short of a chemical analysis! If they really are bronze,
they might be the only people in the USA that have them!

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...
I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

I have been carrying on a parallel thread in r.c.metalworking. We found
a couple of sources for bronze and red brass pipe including the one Jim
found but not threaded nipple. Also they don't deal with small
quantities. You might find red brass nipples is an old fashioned
hardware store but 99% of the time it is yellow brass.

There is no real way without chemical analysis to determine the exact
alloy but the terms "brass" and "bronze" have no real engineering basis.
With the exception of silicon and some aluminum bronzes, all bronzes
have some zinc in them. To add to the confusion, some bronzes have more
zinc in them that some brasses do.

The only thing I can figure out is that the "true" brasses have copper
and zinc but no tin. If a bronze alloy contains any zinc it also
contains some tin. The tin evidently prevents dezincification. For
example "Naval or Admarilty Brass" is 60% copper, 39% zinc and 1% tin
but it is not subject to dezincification and is actually classified as a
bronze.

Red brass is also actually a bronze rather than a brass. The bronze that
Conbraco and other marine fitting companies use is actually red brass
C83600. 85% copper, 5% lead, 5% tin and 5% zinc. (That from a poster
who works in the casting department of a marine fittings company.)

Yellow brass is a true brass at 63% copper and 37% zinc and highly
suseptable to dezincification. Common brass nipples are yellow brass.
Fortunately it is fairly easy to spot yellow and cartrige brass. Scrape
it with a file. Fresh yellow brass will have the characteristic bright
yellow gold color. Red brass will be more orange.


Keith wrote:
A hardware store near me carries what they claim are bronze pipe nipples.
They are dark, not like yellow brass, except where they are threaded. I used
one to mount an aqualarm next to a strainer. I wish I could figure out how
to verify that, short of a chemical analysis! If they really are bronze,
they might be the only people in the USA that have them!

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...

I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

I agree completely that the terminology is a mess, but have a few quibbles:

"Glenn Ashmore" wrote in message
news:hNXpb.1044$62.448@lakeread04...

snip

There is no real way without chemical analysis to determine the exact
alloy but the terms "brass" and "bronze" have no real engineering basis.

I completely agree -- two of the most misunderstood words in boating are
"brass" and "bronze". And, as noted below, it's even worse than you think.

With the exception of silicon and some aluminum bronzes, all bronzes
have some zinc in them. To add to the confusion, some bronzes have more
zinc in them that some brasses do.

The only thing I can figure out is that the "true" brasses have copper
and zinc but no tin. If a bronze alloy contains any zinc it also
contains some tin.

This might be true of bronzes used in marine applications, but it over
generalizes. My ASM Metals Handbook lists
Commercial Bronze -- 90 Cu, 10 Zn
Jewelry Bronze 87.5 -- Cu, 12.5 Zn

The tin evidently prevents dezincification. For
example "Naval or Admiralty Brass" is 60% copper, 39% zinc and 1% tin
but it is not subject to dezincification and is actually classified as a
bronze.

Apparently so.
Inhibited Admiralty -- 71 Cu, 28 Zn, 1 Sn
suggests this from the name and the ASM notes say, "Inhibitors are added to
prevent dezincification" and give it good marks for corrosion resistance for
sal****er velocities below 6 fps.

Red brass is also actually a bronze rather than a brass.

I don't understand why you say this is a bronze. The only ASM listing for
"Red Brass" is
Red Brass 85% -- 85 Cu, 15 Zn
The ASM doesn't show corrosion information, but mentions using it for heat
exchanger tubes. This material is also known as Red Brass (230).

The bronze that
Conbraco and other marine fitting companies use is actually red brass
C83600. 85% copper, 5% lead, 5% tin and 5% zinc. (That from a poster
who works in the casting department of a marine fittings company.)

Note that the lead doesn't do anything for us except that it makes it easier
to machine and therefore cheaper (Hah!).

Yellow brass is a true brass at 63% copper and 37% zinc and highly
suseptable to dezincification. Common brass nipples are yellow brass.
Fortunately it is fairly easy to spot yellow and cartrige brass. Scrape
it with a file. Fresh yellow brass will have the characteristic bright
yellow gold color. Red brass will be more orange.

Roger Pretzer, Marine Metals Manual, International Marine, 1975, page 18,
says, "Brass with a high zinc content (over 16%) is subject to a type of
corrosion known as dezincification." He goes on to say that the color is a
good guide as follows:
red 5% zinc
bronze 5-10% zinc
gold 10-15% zinc
yellow 15% zinc

I'm not sure I can distinguish those subtleties, but it does suggest that
red is OK. And Red Brass 85% should be OK for our use.

For many more brasses and bronzes, but not a whole lot of useful information
on corrosion, go to
www.matweb.com/

Getting back to your original question, I'm not sure that knowing that Red
Brass is probably OK in seawater will help. I'd still worry about galvanic
action over time if you thread Red Brass into C83600 -- certainly the
voltage differences are very small, but they're working 24/7. This is why
we used PVC on Swee****er -- I ruled out the copper alloys because I
couldn't hope to find all the necessary bits in one alloy.



Jim Woodward
www.mvFintry.com


Keith wrote:
A hardware store near me carries what they claim are bronze pipe
nipples.
They are dark, not like yellow brass, except where they are threaded. I
used
one to mount an aqualarm next to a strainer. I wish I could figure out
how
to verify that, short of a chemical analysis! If they really are bronze,
they might be the only people in the USA that have them!

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...

I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Yea, I was thinking those nipples might be red brass. I suppose I'll need to
replace a close nipple with two bronze hose barbs and a short piece of hose.
Just one more thing....

"Jim Woodward" jameslwoodward at attbi dot com wrote in message
...
I agree completely that the terminology is a mess, but have a few
quibbles:

"Glenn Ashmore" wrote in message
news:hNXpb.1044$62.448@lakeread04...

snip

There is no real way without chemical analysis to determine the exact
alloy but the terms "brass" and "bronze" have no real engineering basis.

I completely agree -- two of the most misunderstood words in boating are
"brass" and "bronze". And, as noted below, it's even worse than you think.

With the exception of silicon and some aluminum bronzes, all bronzes
have some zinc in them. To add to the confusion, some bronzes have more
zinc in them that some brasses do.

The only thing I can figure out is that the "true" brasses have copper
and zinc but no tin. If a bronze alloy contains any zinc it also
contains some tin.

This might be true of bronzes used in marine applications, but it over
generalizes. My ASM Metals Handbook lists
Commercial Bronze -- 90 Cu, 10 Zn
Jewelry Bronze 87.5 -- Cu, 12.5 Zn

The tin evidently prevents dezincification. For
example "Naval or Admiralty Brass" is 60% copper, 39% zinc and 1% tin
but it is not subject to dezincification and is actually classified as a
bronze.

Apparently so.
Inhibited Admiralty -- 71 Cu, 28 Zn, 1 Sn
suggests this from the name and the ASM notes say, "Inhibitors are added
to
prevent dezincification" and give it good marks for corrosion resistance
for
sal****er velocities below 6 fps.

Red brass is also actually a bronze rather than a brass.

I don't understand why you say this is a bronze. The only ASM listing for
"Red Brass" is
Red Brass 85% -- 85 Cu, 15 Zn
The ASM doesn't show corrosion information, but mentions using it for heat
exchanger tubes. This material is also known as Red Brass (230).

The bronze that
Conbraco and other marine fitting companies use is actually red brass
C83600. 85% copper, 5% lead, 5% tin and 5% zinc. (That from a poster
who works in the casting department of a marine fittings company.)

Note that the lead doesn't do anything for us except that it makes it
easier
to machine and therefore cheaper (Hah!).

Yellow brass is a true brass at 63% copper and 37% zinc and highly
suseptable to dezincification. Common brass nipples are yellow brass.
Fortunately it is fairly easy to spot yellow and cartrige brass. Scrape
it with a file. Fresh yellow brass will have the characteristic bright
yellow gold color. Red brass will be more orange.

Roger Pretzer, Marine Metals Manual, International Marine, 1975, page 18,
says, "Brass with a high zinc content (over 16%) is subject to a type of
corrosion known as dezincification." He goes on to say that the color is a
good guide as follows:
red 5% zinc
bronze 5-10% zinc
gold 10-15% zinc
yellow 15% zinc

I'm not sure I can distinguish those subtleties, but it does suggest that
red is OK. And Red Brass 85% should be OK for our use.

For many more brasses and bronzes, but not a whole lot of useful
information
on corrosion, go to
www.matweb.com/

Getting back to your original question, I'm not sure that knowing that Red
Brass is probably OK in seawater will help. I'd still worry about
galvanic
action over time if you thread Red Brass into C83600 -- certainly the
voltage differences are very small, but they're working 24/7. This is why
we used PVC on Swee****er -- I ruled out the copper alloys because I
couldn't hope to find all the necessary bits in one alloy.



Jim Woodward
www.mvFintry.com


Keith wrote:
A hardware store near me carries what they claim are bronze pipe
nipples.
They are dark, not like yellow brass, except where they are threaded.
I
used
one to mount an aqualarm next to a strainer. I wish I could figure out
how
to verify that, short of a chemical analysis! If they really are
bronze,
they might be the only people in the USA that have them!

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...

I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer.
Engine
cooling water is supplied through a 1" hose that comes off a
2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1"
wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or
lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

I did a search for "tonval" on the matweb site, but could not find anything.

I have seen that advertised by some of the UK marine harware suppliers as
being dezincification resistant.
But I am not sure whether it is really suitable for seawater intakes.

Whadya think?

garry



"Jim Woodward" jameslwoodward at attbi dot com wrote in message
...
I agree completely that the terminology is a mess, but have a few
quibbles:

"Glenn Ashmore" wrote in message
news:hNXpb.1044$62.448@lakeread04...

snip

There is no real way without chemical analysis to determine the exact
alloy but the terms "brass" and "bronze" have no real engineering basis.

I completely agree -- two of the most misunderstood words in boating are
"brass" and "bronze". And, as noted below, it's even worse than you think.

With the exception of silicon and some aluminum bronzes, all bronzes
have some zinc in them. To add to the confusion, some bronzes have more
zinc in them that some brasses do.

The only thing I can figure out is that the "true" brasses have copper
and zinc but no tin. If a bronze alloy contains any zinc it also
contains some tin.

This might be true of bronzes used in marine applications, but it over
generalizes. My ASM Metals Handbook lists
Commercial Bronze -- 90 Cu, 10 Zn
Jewelry Bronze 87.5 -- Cu, 12.5 Zn

The tin evidently prevents dezincification. For
example "Naval or Admiralty Brass" is 60% copper, 39% zinc and 1% tin
but it is not subject to dezincification and is actually classified as a
bronze.

Apparently so.
Inhibited Admiralty -- 71 Cu, 28 Zn, 1 Sn
suggests this from the name and the ASM notes say, "Inhibitors are added
to
prevent dezincification" and give it good marks for corrosion resistance
for
sal****er velocities below 6 fps.

Red brass is also actually a bronze rather than a brass.

I don't understand why you say this is a bronze. The only ASM listing for
"Red Brass" is
Red Brass 85% -- 85 Cu, 15 Zn
The ASM doesn't show corrosion information, but mentions using it for heat
exchanger tubes. This material is also known as Red Brass (230).

The bronze that
Conbraco and other marine fitting companies use is actually red brass
C83600. 85% copper, 5% lead, 5% tin and 5% zinc. (That from a poster
who works in the casting department of a marine fittings company.)

Note that the lead doesn't do anything for us except that it makes it
easier
to machine and therefore cheaper (Hah!).

Yellow brass is a true brass at 63% copper and 37% zinc and highly
suseptable to dezincification. Common brass nipples are yellow brass.
Fortunately it is fairly easy to spot yellow and cartrige brass. Scrape
it with a file. Fresh yellow brass will have the characteristic bright
yellow gold color. Red brass will be more orange.

Roger Pretzer, Marine Metals Manual, International Marine, 1975, page 18,
says, "Brass with a high zinc content (over 16%) is subject to a type of
corrosion known as dezincification." He goes on to say that the color is a
good guide as follows:
red 5% zinc
bronze 5-10% zinc
gold 10-15% zinc
yellow 15% zinc

I'm not sure I can distinguish those subtleties, but it does suggest that
red is OK. And Red Brass 85% should be OK for our use.

For many more brasses and bronzes, but not a whole lot of useful
information
on corrosion, go to
www.matweb.com/

Getting back to your original question, I'm not sure that knowing that Red
Brass is probably OK in seawater will help. I'd still worry about
galvanic
action over time if you thread Red Brass into C83600 -- certainly the
voltage differences are very small, but they're working 24/7. This is why
we used PVC on Swee****er -- I ruled out the copper alloys because I
couldn't hope to find all the necessary bits in one alloy.



Jim Woodward
www.mvFintry.com


Keith wrote:
A hardware store near me carries what they claim are bronze pipe
nipples.
They are dark, not like yellow brass, except where they are threaded.
I
used
one to mount an aqualarm next to a strainer. I wish I could figure out
how
to verify that, short of a chemical analysis! If they really are
bronze,
they might be the only people in the USA that have them!

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...

I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer.
Engine
cooling water is supplied through a 1" hose that comes off a
2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1"
wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or
lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Glenn Ashmore" wrote in message
news:6tRpb.999$62.845@lakeread04...
I am building a manifold to feed the washdown pump, air conditioning
cooling pump and watermaker bost pump. The supply is a 1 1/2" hose
coming from a 1 1/2" bronze seacock and Groco 970-1515 strainer. Engine
cooling water is supplied through a 1" hose that comes off a 2"x1.5"x1"
Groco manifold at the strainer

I would use bronze reducing tees except that nobody makes bronze pipe
nipple. Only steel, brass or stainless. All three of which are not
acceptable. So I have decided to fabricate it from a length of 1" wall
PVC tube with 1/2" threaded schedule 80 stubs for the valves.

Now comes the question of the valves themselves. I have some Conbraco
bronze ball valves that would work but my experience with them in the
past has not been all good. While the valve body is bronze the handle
is mild steel. On several deliveries of older boats the handles have
rusted to the point of being unusable and I have had to resort to Vice
Grips to operate the valve.

OTOH, I also have some Schedule 80 all PVC ball valves with stainless
handle retaining screws. I know that ABYC frowns on using PVC on
throughhulls but if the throughhull has a bronze seacock what are the
rules for down stream valves?

I don't think ABYC cares too much of what is downstream of the seacock.
Figure it out this way, if one of your PVC valves fail, it won't sink the
boat because you can close the seacock easily. You could also use Marelon
if you're worried about the strength of the PVC valves.

The only thing that worries me about all this manifold is the engine pump
starving the R.O. or AC pump because it sucks harder. On commercial ships,
the seachest is big enough to deal with this issue, but if I'm reading you
correctly, a single 2" intake is supplying everything?

--
Evan Gatehouse

you'll have to rewrite my email address to get to me
ceilydh AT 3web dot net
(fools the spammers)

I'd second Evan's condern. I was on a boat once which had a head
feeding off the same intake as the genset. In a short time, the
genset dried out the head valves and pump and made them useless.
Replacement of the valves and pump leather and a check valve helped,
but you still couldn't flush the head with the genset running.

Michael Porter



"Evan Gatehouse" wrote:

snip

I don't think ABYC cares too much of what is downstream of the seacock.
Figure it out this way, if one of your PVC valves fail, it won't sink the
boat because you can close the seacock easily. You could also use Marelon
if you're worried about the strength of the PVC valves.

The only thing that worries me about all this manifold is the engine pump
starving the R.O. or AC pump because it sucks harder. On commercial ships,
the seachest is big enough to deal with this issue, but if I'm reading you
correctly, a single 2" intake is supplying everything?

Michael Porter Naval Architect / Boatbuilder
mporter at mp-marine dot com
www.mp-marine.com

Yes, but. It's all a matter of sizing, as big ships do it all the time and
I really prefer having only one intake seacock -- when we bought Swee****er
she had ten. Aside from cutting down on intakes, it allows you to put the
seawater intake on one side of the keel and the head discharges on the other
(ours were LectraSan treated, but at sea it has to get overboard even from a
holding tank).

We did this without problems with a 2" seacock on Swee****er. The main was
a Yanmar 4JH2-DTE (75hp) and we had no problem with starving any of the
smaller devices (3 air conditioners on one March pump, 5kw genset, 2 manual
heads, refrigeration condensers (220VAC -- March pump), watermaker, and
galley foot pump). The March pumps did give trouble in trade winds
conditions when there was a lot of air under the boat, but that was with the
engine off.

Glenn's 1.5" seacock is only roughly half the capacity of a 2", so I might
worry a little about it, but my guess is it's OK.


--
Jim Woodward
www.mvFintry.com


"Michael Porter" wrote in message
...
I'd second Evan's condern. I was on a boat once which had a head
feeding off the same intake as the genset. In a short time, the
genset dried out the head valves and pump and made them useless.
Replacement of the valves and pump leather and a check valve helped,
but you still couldn't flush the head with the genset running.

Michael Porter



"Evan Gatehouse" wrote:

snip

I don't think ABYC cares too much of what is downstream of the seacock.
Figure it out this way, if one of your PVC valves fail, it won't sink the
boat because you can close the seacock easily. You could also use
Marelon
if you're worried about the strength of the PVC valves.

The only thing that worries me about all this manifold is the engine pump
starving the R.O. or AC pump because it sucks harder. On commercial
ships,
the seachest is big enough to deal with this issue, but if I'm reading
you
correctly, a single 2" intake is supplying everything?

Michael Porter Naval Architect / Boatbuilder
mporter at mp-marine dot com
www.mp-marine.com