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kiltym 02-07-2013 17:45

Yanmar SD20 Kingston Seacock raw water valves
 
About every 2 years I have to replace the valves that screw into the SD20's for the raw water cooling of my engines.

Since the last time I replaced them (about 18 months ago), I have religiously opened and closed them every week, as well as apply some oil to them in an attempt to keep the working. But, now they are getting stuck. I know each valve requires about 10 rotations to fully close, and now cannot get that many turns, about 8.5, and have broken the SS stem by applying to much pressure when (carefully) trying to loosen them up.

Why Yanmar does not make these with a ball valve is beyond me.

Has anyone found a good replacement ball valve for these? When I have tried to assemble something it turns into about 8" long and I worry about having something that long sticking out the side of the SD in case it got stepped on.

Thanks in advance for any suggestions. I can easily put a Marelon ball valve inline in the hose, and simply ignore the valves at the SD, but would prefer to just eliminate them all together.

colemj 03-07-2013 08:00

Re: Yanmar SD20 Kingston Seacock raw water valves
 
The valves on the Volvo saildrives are ball valves. Perhaps those have the same threads and will fit instead?

Mark

kiltym 03-07-2013 10:54

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Thanks. Will check into this and post what info I find if they might fit.

kiltym 03-07-2013 10:59

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Oh yea, is there a specific model Volvo saildrive I should be looking at?

Probably their smallest one?

colemj 03-07-2013 11:07

Re: Yanmar SD20 Kingston Seacock raw water valves
 
The 120S is the model we have and the ball valves screw onto a nipple in the saildrive housing. I would guess the diameter is ~16mm.

I don't know if the Yanmar valves are similar.

It seems like any ball valve you can find with the correct threads would work.

Do yourself a favor and on the next haulout install dedicated thruhulls/valves for the engines. That's how ours are and the saildrive valves are capped off. No messing with barnacles or valves, etc.

Mark

kiltym 03-07-2013 11:25

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Yes, have thought about a separate thru hull as I know you have, but so far we have had no issues with water flow through the drive unit itself.

I have looked for generic ball valves, but as I wrote before, by the time I assemble all the parts together to go from the SD thread to the hose barb, its like 8" long and annoying. The nice thing about the Yanmar valve is it is compact, and has the correct fittings forged into it, not added to it as would need to be done with a standard ball valve. But, life is a compromise, just want to come up with a good solution to replace them with when the opportunity arises.

I have to imagine someone has done this already. I cant be the only one with 6 sticky valves in 6 years.....

colemj 03-07-2013 11:36

Re: Yanmar SD20 Kingston Seacock raw water valves
 
I don't know what the Yanmar one looks like. The Volvo looks like a short pipe nipple screwed into the saildrive with an Apollo-style ball valve screwed onto it. The whole thing is about 4" long.

The problem is probably the metric threads - maybe you will have better luck finding parts that fit directly now.

Mark

kiltym 04-07-2013 10:25

Re: Yanmar SD20 Kingston Seacock raw water valves
 
The Yanmar ones are essentially a single piece unit with a thread on one side, a hose barb on the other, and the handle for the valve. The total size is more like 2”. It’s a nice little piece of work, if only they used a ball valve.

Do you know what material the nipple is that attaches to the SD? I have read about some people using SS, which seems crazy to me on am aluminum SD.

The ones from Yanmar look like brass, but seems more likely it is polished bronze.

Also found a material called DZR brass, is this suitable on a boat? Just curious as I thought you might know.

I assume I should assemble bronze fittings for it, and once I find all the bits and correct sizes I will post everything here.

colemj 04-07-2013 10:43

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Ours are definitely some type of bronze, although bronze is about the same from aluminum galvanically as SS. Ours are bedded with a thick compound in the threads. Sounds like the Yanmar ones are more compact.

I don't know anything about DZR brass, but it seems like a good fit for a boat and aluminum.

You can always get aluminum valves and pipe fittings if you are worried. Also monel, if you find a lot of money...

Mcmaster-carr sells all sorts of pipe and valves in different materials if you find a way to ship to where you are.

The Gambiers must have quite the hardware stores!

Mark

kiltym 04-07-2013 10:55

Re: Yanmar SD20 Kingston Seacock raw water valves
 
No good hardware stores, but the baguettes more than make up for it.....

Thanks for the additional info.

mfeene01 04-07-2013 12:24

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Hi Mark. Hope things are well. Say Hello to Leisbet for us.

As far as the valves go, I put a ball valves between the sail drive units and their raw water strainers. Haven't tried to turn off the Yanmar valves since.

No mus, no fuss and it's easy to clean the strainers.

Mike & Patti
Lauren Marie

gspeak 06-07-2013 22:52

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Had our Yanmar SD20 valves replaced with S/S elbows, nipples & ball valves at Easter.

This is the parts list the mechanic billed me for:
2 x #45545 Valve Ball S/S 15mm 1/2"
2 X #3HN015 Hex Nipple 15NB 1/2" 316S/S
Elbow S/S 1/2"

See photos:

https://www.oz-e.com.au/seabreeze/ball-valve1.jpg

https://www.oz-e.com.au/seabreeze/ball-valve2.jpg

Dave

Seabreeze
L380 #241

kiltym 06-07-2013 23:32

Quote:

Originally Posted by gspeak (Post 1278972)
Had our Yanmar SD20 valves replaced with S/S elbows, nipples & ball valves at Easter.

This is the parts list the mechanic billed me for:
2 x #45545 Valve Ball S/S 15mm 1/2"
2 X #3HN015 Hex Nipple 15NB 1/2" 316S/S
Elbow S/S 1/2"

See photos:

Dave

Seabreeze
L380 #241

Thanks.

Couple of questions if you don't mind.

The threads are BSP, correct? As opposed to NPT. I think you are in Australia based on photo links, and assume there it is BSP?

What is the thick red paste used on the threads? Obviously some type of pipe dope, was this instead of teflon tape, or something to help insulate the SS from aluminum?

No worries about the stainless and aluminum saildrive becoming permanently bonded due to corrosion?

Thanks again for any further info.

gspeak 06-07-2013 23:57

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Quote:

Originally Posted by kiltym (Post 1278984)
Thanks.

Couple of questions if you don't mind.

The threads are BSP, correct? As opposed to NPT. I think you are in Australia based on photo links, and assume there it is BSP?

What is the thick red paste used on the threads? Obviously some type of pipe dope, was this instead of teflon tape, or something to help insulate the SS from aluminum?

No worries about the stainless and aluminum saildrive becoming permanently bonded due to corrosion?

Thanks again for any further info.

Mark,
Sorry I can't give you a lot of detail as I left it to the mechanic who said he has done a lot of these conversions. He did give me the option of going with new dedicated through hulls for the conversion also, but I went with replacing the Yanmar valves as I prefer less holes in the hulls.

I'm pretty sure they are BSP threads, but not 100% sure. Not sure of the paste used also, but have a feeling he used thread tape as well. Maybe the paste is used to isolate even more.

I assume that the corrosion problem with the dissimilar metals is hopefully being taken care of by the pencil anodes in the sail drives, which he also replaced.

Maybe someone else can chime in with their take on the particulars.

Dave

Seabreeze
L380 #241

colemj 07-07-2013 07:16

Re: Yanmar SD20 Kingston Seacock raw water valves
 
This is exactly what our Volvo's look like, except the fittings are bronze and the thick pipe dope is yellowish.

Mark

kiltym 07-07-2013 15:23

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Thanks for all the help and info.

I think we will go with DZR brass or bronze, depending on what is available locally (in Tahiti). I think either is a bit better than SS with the aluminum, and I tend to be on the conservative side with this. Prices are similar for all three materials.

Have to figure out what type of pipe dope we should use, or ask around. I don't think using both tape and dope is normally done, seems it is advised to use one or the other. Seems the thicker the better based on the two installs discussed here.

Since they are tapered threads, and seal from the threads more then the dope or tape, I wonder about using tape, and then coating that in Tef-Gel to minimize any chance of corrosion. Just don't know if the Tef-Gel and teflon tape can live happily together.

I am pretty sure the threads are 1/2" BSP based on a post on another forum, for others looks for the correct parts.

Thanks again for the help, now to find the parts.

DotDun 07-07-2013 15:33

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Let us know how it turns out.

Watercolor 17-07-2013 11:27

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Don't know if it will help, but there is a yard in oriental, NC - boatyard@deatonyachts.com - that may be of help. The owner John Deaton has worked on Yanmars for some 20 or thirty years, it's his specialty. I'm sure if you emailed him he'd respond promptly as to the thread type and best metal options. My guess is it's a tapered metric thread.

I think you'd be better off with a good thread sealant than tape or tape/thread combination. The metal threads tend to cut the tape exposing the metal. The sealant would tend to create a more even and consistent barrier.

Another option might be to put in a thread to barb elbow and have the valve insulated completely from the engine by way of the hoses. I'd use a very high quality hose between the engine and the valve. It would address the corrosion issue and mean that you weren't dependent on any specific threads for the valve especially where you're sailing.

Fair winds

kiltym 17-07-2013 12:34

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Thanks.

I am waiting for an update from Torrenson Marine (from Yanmar), on the threads and the metal that is used in the OEM valves.

I am fairly certain the threads are 1/2" BSP based on a thread on another forum by someone who changed them with SS parts. Pretty much all pipe fittings are BSP (except in the U.S.).

I will probably go with DZR brass on our replacements, but am still waiting to hear back from Torrenson. Once I know more, will post it here.

Do agree with using thread sealant, think it will protect a bit better. On the existing OEM valves I have replaced, I always used tape, probably because that was what was used when I took them off the first time. I have a suspicion the OEM valves are DZR brass as well, but am hoping for confirmation from Yanmar.

I will email your contact as well to get his thoughts and re-post here as well.

kiltym 17-07-2013 18:45

Re: Yanmar SD20 Kingston Seacock raw water valves
 
It's amazing no one has a good answer to this issue.

Here is a link to the thread size info:

https://www.cruisersforum.com/forums/...ml#post1125294

It should be 1/2" BSP.

As far as material, still waiting for a response from Yanmar, but not expecting it to be honest. Seems Volvo folks have tried to find out the material on their's as well with no luck:

VP Saildrive- Seacock Material? [Archive] - Yachting and Boating World Forums

The reply I got back from John Deaton was:

"With respect to the ABYC standards, bronze or brass should not be in contact with aluminum in an underwater setting; with that, SS would be the best choice unless you could find an aluminum bodied valve in BSP."

Interesting, but does not jive with what is installed on most boat's SD's it seems (except some who have installed SS valves/fittings), and certainly not the OEM stuff from Yanmar or Volvo.

Wow, who would have thought this was all such a mystery.

As I find out more, I will share.

Watercolor 17-07-2013 19:11

Re: Yanmar SD20 Kingston Seacock raw water valves
 
When you say, BSP you mean BSPT or BSPP? My guess is it's BSPT?

And isn't everything else on the Yanmar metric?

Sometimes you need to know the answer, before you can ask the question.

Again,

Fair Winds and best of luck on getting the right answers.

kiltym 18-07-2013 01:23

My understanding is that with BSP, the male thread is tapered and the female parallel. But I think that is all standard when you order BSP fittings. I am pretty sure that is the only way they come.

Also, John confirmed that he believes they are BSP as that is what Yanmar typically uses.

Watercolor 19-07-2013 10:32

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Kiltym -

First, you state, " John confirmed that he believes they are BSP as that is what Yanmar typically uses."

BSP (British Standard Pipe) is simply a set of thread standards. You need to know whether it is BSPP (British Standard Pipe Parallel) or BSPT (British Standard Pipe Tapered if you want a correct fit. What I've seen is that NPS is considered to be an acronym for National Pipe Standard when it is National Pipe STRAIGHT (all threads the same.). The British use the term PARALLEL to define all threads being the same. Tapered is tapered, where female threads start with a thread or two equal to the straight thread dimensions and then taper down and the male threads start small and taper up to the straight thread dimensions. All John is confirming is that it may be a BSP thread.

NPT: National Pipe Taper correspond to BSPT
NPS: National Pipe Straight correspond to BSPP

You stated, "My understanding is that with BSP, the male thread is tapered and the female parallel."

The answer to this is NO. BSPP (parallel) and BSPT (tapered) threads are not compatible and the same would be true for NPT and NPS threads.

And, YES the male BSPT fitting will thread into the BSPP female fitting. The reverse will not work. However, the male thread will have most likely only one or two BSPP threads at the back end of the fitting. Neither a good sealing option or thread purchase option, but it will work in a pinch.

Here's a thought, on the old Yanmar fitting/valve that screws into the engine block, was there a gasket or O-ring as part of the fitting? Or is there an internal shelf that will stop the male fitting. Or did you simply use some paste or tape on the threads and then screw it in till it stopped turning. If there is no shelf or O-ring/gasket as part of the original Yanmar valve/fitting assembly then the threads are most likely tapered. Most pipe threads are tapered if they have no compression gasket or o-ring. I very much doubt that Yanmar would use a female BSPP thread on the engine and a male BSPT thread on the valve/fitting. Just simply not good engineering.

Here’s some additional food for thought info.

I'm not an expert on BSP threads, but do know that the differences between NP and BSP do not effect the thread type, tapered or parallel. In other words, NPS (National Pipe Straight and BSPP (British Standard Pipe Parallel) have the same basic configuration and function. They all screw in till they bottom out, and their sealing quality is by a bottom or top compression, usually with an O ring or gasket. They are basically the same as the threads on a nut and bolt.

If you look at an NPS and BSPP set of threads you'll see that every thread is the same. If you put a caliper on them both the internal fitting surface and the thread peak surface would be parallel.

I call these threads "sloppy" when it comes to sealing. Again, all the sealing is done by top and bottom compression.

NPT (National Pipe Tapered) and BSPT (British Standard Pipe Tapered) are designed to seal, not by compression, but by the meshing of the threads with one another (with the help of a little paste or tape. Although, given the low pressures involved on most thru-hull related applications a paste or tape on a parallel thread will suffice.

A tapered thread is designed to thread in only so many turns before maximum sealing occurs. And should require only minimum sealant to achieve reasonably high pressure sealing. In fact, there is a form of tapered threads NPTF (National Pipe Tapered Fine) that is so close tolerance machined that it will seal with no sealant.

An NPT 1/2" tapered thread according to the ASTM standard should have 14 threads/inch and have a hand-tight engagement of 4.48 turns. The BSPT 1/2" threads will have a similar, but slightly different, set of specifications. In theory, you should get maximum sealing at a point just over the number of hand tight turns.

The BSPP female thread needs to accept 6.48 threads to get any real mechanical purchase; the 4.48 threads with a 3.20 inch length – the are in effect doing very little with regard to either mechanical purchase or sealing.

kiltym 19-07-2013 11:12

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Thanks for all the clarification.

There is no O-Ring, only the threads seal, so I will assume it is BSPT. I guess my quick look online may have provided slightly wrong information. Have used tape before when changing them out, and all has been fine.

However, not to start an argument, but based on the links below to the products I ordered, I also assumed only the male threads were tapered since the male state BSPT and the female BSP. From Wikipedia (not that I believe everything I read here, but where I got some of my limited info).

British Standard Pipe - Wikipedia, the free encyclopedia

"These can be combined into two types of joints:
Jointing threads: These are pipe threads where pressure-tightness is made through the mating of two threads together. They always use a taper male thread, but can have either parallel or taper female threads. (International standards require all female threads to be parallel.)

Longscrew threads: These are parallel pipe threads used where a pressure-tight joint is achieved by the compression of a soft material (such as an o-ring seal or a washer) between the end face of the male thread and a socket or nipple face, with the tightening of a backnut."

So you stating they are not compatible (tapered and parallel), may not be correct and hence my comments from before.


Some feedback as well from people over the past 24 hours. I think this pretty much sums things up now.

From Mastry:

"I think you are correct my information tells me it is ½ BSP"

Also from Mastry:

"The material is brass."

From Torrenson;

"The metal used to make the 196420-02290 valve very likely is a brass alloy rather than bronze; while more noble than brass, bronze has certain properties which make it less suitable for manufacturing things like little valves out of it. Brass is easier, and still decent nobility-wise. ABYC doesn't like brass in underwater fittings, though - when subjected to a galvanic environment, brass can "bleed" out the component zinc, and can thereby become quite brittle. ABYC guys have nightmares about somebody's raw water intake seacock snapping off without warning because it got the zinc sucked out of it over time.

Stainless offers less opportunity for disaster, hence their rule. However, Yanmar chose brass, regardless of ABYC rules (which are guidelines, not law), for reasons probably entirely logical and defensible to them."

Note that using DZR brass avoids the "bleed" issue mentioned above, which is why I ordered DZR Brass (mostly available in Europe is seems).

I have ordered the following parts, for anyone else looking to replace these:

DZR CR Ball Valve Seacock (Note the product info at the bottom, BSP FEMALE PORTS)

DZR 1/2" Male Equal Nipple (Note the product info description, BSPTM (BSP Tapered Male))

The hose barb on the OEM part is 5/8". I could only find a straight barb that size, so if it is important to have 90 degree turn, will have to look elsewhere.

Hose Tail DZR 1/2" BSP to 16mm (Note the product info description, 1/2"BSPT MALE)

Watercolor 24-07-2013 10:00

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Mark,

I don’t consider your comments to be in anyway argumentative.
I really appreciate the dialogue and information, in particular the WIKI statement “They always use a taper male thread, but can have either parallel or taper female threads. (International standards require all female threads to be parallel.)” Especially, with regard to what ISO calls joining threads (BSPT or NPT). It forces me to think and I learn every time.

To be honest the ISO statement makes no sense to me. I tried to find the source of the original statement to see if it was an editing error. No luck one-way or the other.

My basic response is that I stand by my original statement.

“The answer to this is: NO. BSPP (parallel) and BSPT (tapered) threads are not compatible and the same would be true for NPT and NPS threads.

And, YES the male BSPT fitting will thread into the BSPP female fitting. The reverse will not work. However, the male thread will have most likely only one or two BSPP threads at the back end of the fitting. Neither a good sealing option or thread purchase option, but it will work in a pinch.”

The reason is simple. As I said the male BSPT part will screw into the BSPP female part easily. But the male part is then nothing more than a longscrew (BSPP) threaded part with the first .320” threads (4.5 threads) being BSPT. A ½” male BSPT fitting that has ½” of thread will have, approximately 4.5 tapered threads (BSPT) with an additional 1 or 2 parallel threads (BSPP).

Functionally, the male BSPT part becomes nothing more than a 2 threaded BSPP fitting. The 4.5 BSPT threads in this scenario have no real sealing or purchase value. Think of it as a set of lines, the female threaded part is a straight line (say 2”) and the male threads are a combination of a short straight ¼” line (the 2 BSPP threads) followed by a ¾” downward tapering line (the 4.5 BSPT threads). This combined line sets slightly below the straight line. In effect, you get none of the sealing qualities of the BSPT threads and marginal threaded capacity of the BSPP threads. What you do get is an unnecessary gap caused by the tapered BSPT and the BSPP threads.

You now come under the guidelines of “Longscrew or BSPP threads and they are: parallel pipe threads used where a pressure-tight joint is achieved by the compression of a soft material (such as an o-ring seal or a washer) between the end face of the male thread and a socket or nipple face”

If both your parts are tapered, then using tap or paste is a matter of choice. If you use tape, use as few wraps as possible, you want to try and not have the threads cut the tape. Parallel threads without a gasket probably a combination would be best. Paste wrapped with tape?

With a tapered/parallel joint the issue is really how to fill in the tapered/parallel gap without cutting the tape. Maybe a lot of paste on the tapered threads and 2 wraps of tape?

I understand the constraints that you’re under, especially where access to parts is difficult. And I’m sure you’re end product will work just fine. I felt I had to comment on the ISO statement about using BSPP and BSPT threaded parts. My position is simply parallel with parallel, tapered with tapered whenever possible and know the function of each.

Fair winds,

Jed

masterov 03-05-2018 16:50

Re: Yanmar SD20 Kingston Seacock raw water valves
 
2 Attachment(s)
Hi All,

I was really glad to find this thread, since I am having the same exact problem on my SD31 and according to the parts catalog, the part number is the same as for SD20. However what I have:

https://www.cruisersforum.com/forums/...1&d=1525390912

looks somewhat different from the part number 196420-02290

https://www.cruisersforum.com/forums/...1&d=1525390912

which is supposed to be replacing 196420-02391.

Well, perhaps yanmar changed the part slightly, however, when I measure the diameter of my part, it measures roughly 34mm, which is 1 5/16 in, which is very different from 1/2in that you are discussing here.

Is SD31 different from SD20 or am I measuring something incorrectly.

If anyone has performed this conversion successfully on SD31, please share the parts and material that you've used!

Much appreciated!
A.

Wotname 03-05-2018 20:33

Re: Yanmar SD20 Kingston Seacock raw water valves
 
FWIW.
Now this old thread has resurfaced and with all the talk of BSP and so on, I understand that Yanmar uses JSP threads on their pipe fittings (Japanese Standard Pipe). The good news is that JSP and BSP are interchangeable (AFAIK).

masterov 04-05-2018 05:16

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Thanks for your reply, Wotname. Now the only questions that remain are:

1. does SD20 and SD31 have the same diameter hole for the fitting?

2. which material is best to use?

Does 1/2" BSP refer to the thread and not to the diameter? If that's the case, what diameter fittings should I get? Does 316S/S describe the diameter? I am sorry for dumb questions, I don't know how the pipe is marked.

Wotname 04-05-2018 05:49

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Quote:

Originally Posted by masterov (Post 2626285)
Thanks for your reply, Wotname. Now the only questions that remain are:

1. does SD20 and SD31 have the same diameter hole for the fitting?

2. which material is best to use?

Does 1/2" BSP refer to the thread and not to the diameter? If that's the case, what diameter fittings should I get? Does 316S/S describe the diameter? I am sorry for dumb questions, I don't know how the pipe is marked.

1. Don't know
2. Depends, usually bronze or stainless steel (SS)
Yes BSP refers to the thread, 1/2" BSP is around 14 or 15 mm in diameter, see more here https://en.wikipedia.org/wiki/British_Standard_Pipe

316 is a grade of stainless steel often referred to "marine grade stainless" while "commercial grade" is 304.

However, it is a complicated subject once you start delving into it :smile:.

Boatguy30 04-05-2018 05:59

Re: Yanmar SD20 Kingston Seacock raw water valves
 
I believe those are a special metric thread. Better to buy the genuine yanmar and make sure to exercise it atleast every oil change

masterov 04-05-2018 08:20

Re: Yanmar SD20 Kingston Seacock raw water valves
 
thanks, Wotname!

Can someone measure the diameter of their pipe, please? Mine measures ~34mm, yet Yanmar dealer assures me that the part is the same for SD31 and SD20.

Boatguy30 - people above are talking about exercising it before every start, otherwise it corrodes. I don't think doing it every oil change will be enough. I tried doing it once a month, and even that was insufficient.

kiltym 04-05-2018 08:29

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Quote:

Originally Posted by masterov (Post 2626364)
Boatguy30 - people above are talking about exercising it before every start, otherwise it corrodes. I don't think doing it every oil change will be enough. I tried doing it once a month, and even that was insufficient.

We did it every week, and still not enough. Within 6 months it would no longer close fully. And we did this on 4 brand new seacocks over 3 years. All the same.

The parts I supplied above all worked (on SD20), and still work just as they should. No special threads involved. Installers and manufacturers should simply replace the part at installation IMO.

masterov 04-05-2018 09:27

Re: Yanmar SD20 Kingston Seacock raw water valves
 
1 Attachment(s)
Thanks, kiltym!

Could you please measure the diameter of your pipe that is screwed into the saildrive?

Mine measures 34mm:

https://www.cruisersforum.com/forums/...1&d=1525451210

which doesn't correspond to 1/2in size of your parts.

kiltym 04-05-2018 09:29

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Quote:

Originally Posted by masterov (Post 2626412)
Thanks, kiltym!
Could you please measure the diameter of your pipe that is screwed into the saildrive?

Sorry, sold the boat......

ggray 06-05-2018 06:35

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Can't help on specifications of these valves, but can say that I'm still using the original 18 year old valves that came on my SD20. Bought one new one as a spare, and at that price, I want to preserve my originals!

Every haulout, I remove and clean them with WD40 (through may open/close), and then lubricate with FluidFilm or some other like lube (through many open/close). And I rarely exercise the valves between haulouts, just when winterizing.

I'm mainly on the lower Chesapeake, so not "full salt".

I modified a socket to operate the valves when tight

masterov 10-05-2018 11:17

Re: Yanmar SD20 Kingston Seacock raw water valves
 
I emailed Yanmar, and got the following response from them. I am surprised that the material is brass.

Hello Alexei,

I would first like to thank you for taking the time to send in your kind inquiry. Second, please excuse my delay in replying as I did not have this information on hand.

Please see information below:

The thread is R1/2-14.

This should be the same as BSP taper thread according to some Google searching.

(Material CW617N = brass).

I hope that this will answer your kind inquiry and hope you have a great day.

​Thanks
Michael Dollfuss
Customer Support Technical Rep.
Customer Support Department
Marine Engine Division
Yanmar Marine International B.V.
(Yanmar Recreational Marine of Americas)

masterov 27-05-2018 09:28

Re: Yanmar SD20 Kingston Seacock raw water valves
 
1 Attachment(s)
Yesterday, I finally found the right size nipple, was very excited, and then lo and behold, I held it next to my saildrive, and it became painfully obvious that the size is not even close.

https://www.cruisersforum.com/forums/...1&d=1527438327

As I said before, the actual part in the saildrive measures 34mm, which is roughly 1 1/3 inches.

Looks like the only option for me is to put the boat on the hard, unscrew the part, and take it with me to the shops in order to find a match. (unless someone can figure it out from the photo)

ggray 27-05-2018 19:43

Re: Yanmar SD20 Kingston Seacock raw water valves
 
I'm not where I can measure anything, but I can say that if the Yanmar Kingston cock is indeed 1/2 inch NPT (and that size seems right to me), the OD of that is .84 inches, smaller than what you have.

Perhaps it's not original?

It is odd that Yanmar has this special fitting. The only reason that comes to my mind is perhaps by closing off the seawater somewhat closer to the housing it is screwed into (as compared to a ball valve), perhaps it is less vulnerable to freezing/bursting when shut off for winterizing. Just a guess.

broken pete 07-11-2019 05:57

Re: Yanmar SD20 Kingston Seacock raw water valves
 
Hi all, I would like to bring this thread back to life if I may?

I am also looking into replacing my seacock with 316 Stainless Steel. I have read through a lot of these threads and it seems to be the bets option, although I have to say it really scares me screwing a stainless nipples and elbows into this cast aluminium saildrive. All the PTFE tape in the world isn't going to put my mind at rest.

But then I look at the old valve, its brass (and not the strongest), its been in the saildrive for 20 years and I cant see a single scrap of corrosion on the thread or the housing.
Perhaps the anodes in the saildrive are arresting the corrosion? is this why they are surviving?

I would also like to point out that my thread is definitely 1/2" NPT and not BSP as commonly assumed. Looks like Yanmar made an American version somewhere down the line.
Thanks all

masterov 07-11-2019 09:47

Re: Yanmar SD20 Kingston Seacock raw water valves
 
1 Attachment(s)
Here is what I did with mine:

https://www.cruisersforum.com/forums/...1&d=1573145230


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