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View Poll Results: What material was used to make the standpipe? | |||
Copper | 10 | 27.03% | |
Steel | 4 | 10.81% | |
Stainless Steel | 10 | 27.03% | |
Black Iron | 8 | 21.62% | |
Bronze | 3 | 8.11% | |
Some Other Material | 1 | 2.70% | |
Don't Know/Can't Tell | 1 | 2.70% | |
Voters: 37. You may not vote on this poll |
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#1
IP: 38.102.16.169
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Standpipe Construction
For those of you with standpipes in their exhaust systems, what material was used to make them?
Bill |
#2
IP: 72.71.243.195
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Bill
I have a Tartan 34 Classic. All originally have a standpipe. The standpipe is made of bronze. Lead up to by black pipe which is threaded into the bottom of the cylinder. Art |
#3
IP: 199.173.225.25
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Black Iron.
Home Depot special ??? - Is the standpipe the same thing as the riser? If not, then I don't have one. |
#4
IP: 173.166.26.241
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Good question. I would say that a standpipe is indeed a riser that elevates the exhaust to such a level that the engine does not have to drive water uphill. So a standpipe is always a riser, but a riser is not a standpipe.
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#5
IP: 72.71.243.195
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Could someone please explain in greater detail the diagram of risers and
standpipes? I think I have a standpipe, especially since the engine is buried in the keel on the Tartan 34C. The water must push uphill though. Thanks Art |
#6
IP: 24.152.131.220
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Art,
Is the question how the standpipe system works or whether or not you have one? Or both?
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#7
IP: 72.71.243.195
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Neil
I believe that I have one, but don't understand how a riser differs and why according to Hanley's post a standpipe doesn't need to lift water. There may be some confusion from others, including myself how the 3 systems work and differ (including water lift. Regards Art |
#8
IP: 173.166.26.241
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Art - The answer is that the standpipe rises so high that when the water is finally injected it is at such a vertical position in the system that the water simply flows downhill and out the transom. The exhaust is not impeded by the water and there is no "batching". Regards, Hanley
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#9
IP: 24.152.131.220
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Yeah Art, understand how it could be confusing.
First, the term 'riser' is used for a variety of things. In our exhaust systems it simply refers to a pipe going up, a component of the system. I used the term over on the 'no more fouled plugs' thread to accurately describe a vertical structural component (bulkheads are perpendicular to the centerline, risers are parallel). You are correct that the raw water must be lifted to a point higher than the waterline in all marine exhaust systems (except keel pipe/dry stack systems that don't pump raw water aboard and therefore don't have to expel it but we're not going there). In the standpipe system the water is lifted by the raw water pump. The waterlift system uses exhaust pressure to lift the water, hence the name. Lifting the water with exhaust pressure diminishes the engine's ability to breathe, although in a properly designed system, not much. See last paragraph for an odd quirk about this. A waterlift system injects the water ahead of the muffler by means of a mixer, usually an inline type like Moyer sells or a mixing elbow like the Westerbeke or Yanmar. A standpipe system injects the water directly into the top of the muffler. A standpipe muffler is always located above the waterline, a waterlift is usually below the waterline and often below the engine. The odd quirk: we've gone 'round and 'round about exhaust hose size and whether bigger is better. With a standpipe system, bigger is better, no question. A waterlift however, reaches a point of diminishing return. As the designed exhaust hose gets larger, so does the water 'batch' the exhaust is trying to push uphill resulting in more backpressure. In this case, the larger hose creates more pressure, the opposite of what you'd think. Strange but true. The optimum design is a hose big enough for the engine to breathe but not too big. Based on a recent poll, it's somewhere between 1 1/2" and 2". Hope this helps.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#10
IP: 206.40.166.218
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Our 1969 Pearson 35 still has the copper standpipe which I believe to be original equipment, although our late model A4 is probably not original to the boat. There's a post from late 2008, I think, that diagrams how the standpipe system works. We've had no trouble with it and to my knowledge neither did the PO. Having said that, knock on wood.
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#11
IP: 72.71.243.195
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Quote:
Regards Art |
#12
IP: 98.248.12.160
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standpipe construction
Nduttion, thanks for the clear explanation, now I have a question regarding the optimum pipe ID size for a water lift system. I am about to replace the hot section of my (Moyer) water lift system and have found reasonably priced 316L pipe components from McMaster Carr for 1 1/4 pipe. They show two wall thicknesses, one Schedule 40 and the thicker wall, Schedule 80. The thicker wall decreases the pipe area by about 15% but affords greater lifetime. From you comments, I gather that I do not want to decrease the pipe area any more than necessary, is that correct?
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#13
IP: 24.152.131.220
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Quote:
Optimum pipe size There was a poll last year on this subject and if I recall, 1 1/4" pipe was the most common. Note that the A-4 exhaust flange is 1 1/4" as is the Moyer mixer and many of us have that size hot section with excellent performance. I don't think anyone is running smaller than 1 1/4". Others strongly advocate larger sizes to 2". Be sure to read the 'odd quirk' in the previous quote. Sch 40 vs. Sch 80 pipe You're talking 316 stainless pipe so I think sch 40 will last a lifetime as it is.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 02-10-2011 at 10:13 PM. |
The Following User Says Thank You to ndutton For This Useful Post: | ||
TimBSmith (10-10-2020) |
#14
IP: 98.248.12.160
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standpipe construction
thanks Ndutton, the 316 listed in McMaster Carr was 316L for low carbon and I think that alloy is very corrosion resistant. For my hot exhaust section, one 4 inch nipple, one 3 1/2 inch nipple and two elbows the cost was about $40, cheap enough once you consider the labor involved. I will stick with the thinner schedule 40.
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The Following User Says Thank You to tartansailboat For This Useful Post: | ||
TimBSmith (10-10-2020) |
#15
IP: 24.152.131.220
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Tom,
The failure of the stainless in only one particular area of the hot section and not others is most interesting. Regarding your new brass hot section, for reasons unknown to me it's non compliant with ABYC standards, section P-1, table 1 found on page 6 of the following attachment. According to them, after the water injection point you're good with brass but not before. Maybe something to do with strength/heat issues as you mentioned. http://www.ntsb.gov/Dockets/Marine/D...012/234864.pdf
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 02-13-2011 at 12:05 AM. |
#16
IP: 173.166.26.241
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As Tom has discovered and correctly reported the environment in the hot section indeed all the way back to the flange is anything but chemical vapor free. That is why it is of utmost importance to construct hot sections from materials as closely resembling the manifold as possible. This means black iron is the #1 choice.
Last edited by hanleyclifford; 02-13-2011 at 08:55 AM. |
The Following User Says Thank You to hanleyclifford For This Useful Post: | ||
TimBSmith (10-10-2020) |
#17
IP: 66.190.36.7
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"A machinist friend has offered to recreate the original structure , using common black pipe , for next to nothing , and I accepted."
The above is from my thread on Standpipe autopsy. I am feeling rather brilliant this morning. Never mind that I made my choice based on economy; I like to think that it was my inner metallurgist speaking.
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1966 Columbia 34 SABINA |
#18
IP: 71.168.64.202
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Quote:
If you still have the original bronze standpipe, maybe you could revert to it. I had my bronze standpipe cleaned 12 years ago, installed new black iron pipe, and it has been problem free ever since. I know that you have a rear exiting exhaust rerouting, would the standpipe still be compatible with your rerouted exhaust? Regards Art |
#19
IP: 174.94.22.175
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Quote:
Tom, wondering if it was straight 316 or 316(L)? Also, were there any welded sections in the tee or was it a cast piece? Cheers! |
#20
IP: 108.8.42.107
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stand pipe
Quote:
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#21
IP: 199.173.224.31
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Well crap - I was just about to order stainless pipe to make a hot section
Is there any such thing as BRONZE pipe and fittings or is it all brass? |
#22
IP: 50.54.220.1
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Is this a standpipe????
Last edited by urchin; 06-15-2012 at 09:51 AM. |
#23
IP: 24.152.131.155
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Is what a standpipe? No picture attached.
Aah, there it is. Yes, standpipe.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 06-15-2012 at 10:25 AM. |
#24
IP: 71.168.64.247
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Neil
Standpipes are the type of exhaust used in Tartan 30, 34. See the Moyer catalog for a picture |
#25
IP: 24.152.131.155
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Thanks Art. Urchin, did that answer your question??
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
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