42DS Head Seacock

[henryd]

The aft seacock on my 2010 appears to be leaking and I want to change while still hauled.  I have seen some threads but they do not answer my questions.  What is the size of the seacock in the aft head.  I am in the US and it appears to be 2" but am looking to confirm that it is 2" vs a similar metric size (50mm?).  Also, technique for removing it?  It is in a very tight space.

Henry Duncan
42DS
Perseverance

[Mistroma]

Both forward and aft. heads have 2" valves. I've replaced both over the years, DZR on the forward head and TruDesign on the aft.

Forward head was easy because I was able to spin the valve on and off the elbow on the skin fitting. There's also plenty of spare hose up to the deck and down to the Jabso (no holding tank).

Aft. tank was a real pain for 2 reasons.
1) TruDesign valve is much bigger than DZR and there's not enough room to spin it around in situ.
2) Short, stiff hose section from tail to bottom of holding tank curves up sharply where it touches the hull.


I had to assemble TruDesign in place for a dry run and spin off the skin fitting from below. Then I bonded the elbow at the correct position wrt valve and bonded the tail to the other side. I assembled everything after it had set and screwed the skin fitting on afterwards from outside. Lots of sealant and 2 people needed to put it together that way.

I also had problems with the hose. It's an odd size and one supplier provided some that was just too loose. Then they provide the correct diameter but it was too stiff and wouldn't bend enough. The third lot fitted and could just bend to fit the tank outlet.

The tails are smaller than 2" and getting suitable hose to connect tail and tank might be more of a problem than you'd imagine.

[Tafika II]

I replaced both with Groco bronze valves in 2018 but don't have the part numbers. They are 2", and the hose is a standard 2" pool hose. I'll see if I can send you some photos later this week. As Mistroma says, the front is "easy". The aft is a pain in the A$$. I'm in LA California if you want to talk or email.

[henryd]

Mar 5, 2024 0:51:51 GMT Tafika II said:

I replaced both with Groco bronze valves in 2018 but don't have the part numbers. They are 2", and the hose is a standard 2" pool hose. I'll see if I can send you some photos later this week. As Mistroma says, the front is "easy". The aft is a pain in the A$$. I'm in LA California if you want to talk or email.

Thanks Brent.  I am only dealing with the aft valve presently and will try to remove tomorrow.  Not sure if I will replace with bronze or Marelon as it sounds the space is tough with the plastic option.  What was your approach for removal of the old valve and how difficult was it?  Also, did you change the thru hull.

Henry

[henryd]

Mar 5, 2024 0:42:03 GMT Mistroma said:

Both forward and aft. heads have 2" valves. I've replaced both over the years, DZR on the forward head and TruDesign on the aft.

Forward head was easy because I was able to spin the valve on and off the elbow on the skin fitting. There's also plenty of spare hose up to the deck and down to the Jabso (no holding tank).

Aft. tank was a real pain for 2 reasons.
1) TruDesign valve is much bigger than DZR and there's not enough room to spin it around in situ.
2) Short, stiff hose section from tail to bottom of holding tank curves up sharply where it touches the hull.


I had to assemble TruDesign in place for a dry run and spin off the skin fitting from below. Then I bonded the elbow at the correct position wrt valve and bonded the tail to the other side. I assembled everything after it had set and screwed the skin fitting on afterwards from outside. Lots of sealant and 2 people needed to put it together that way.

I also had problems with the hose. It's an odd size and one supplier provided some that was just too loose. Then they provide the correct diameter but it was too stiff and wouldn't bend enough. The third lot fitted and could just bend to fit the tank outlet.

The tails are smaller than 2" and getting suitable hose to connect tail and tank might be more of a problem than you'd imagine.

Sounds complicated and I have had this type of hose mismatch issue in the past.  I will dry fit when I remove the elbow.  I have the new hose, which appears like it will fit.  I did find the exact hose they used available but would have needed to buy a roll when I only need 18".  I had to cut the old one off.  Any tips on removal of the old valve are welcomed.

[Tafika II]

It was easy—it took three hours—CONFESSION TIME... I had the local yard do it while it was in the sling. That project was well above my paygrade.

[henryd]

Mar 6, 2024 0:11:17 GMT henryd said:

Mar 5, 2024 0:51:51 GMT Tafika II said:

I replaced both with Groco bronze valves in 2018 but don't have the part numbers. They are 2", and the hose is a standard 2" pool hose. I'll see if I can send you some photos later this week. As Mistroma says, the front is "easy". The aft is a pain in the A$$. I'm in LA California if you want to talk or email.

Thanks Brent.  I am only dealing with the aft valve presently and will try to remove tomorrow.  Not sure if I will replace with bronze or Marelon as it sounds the space is tough with the plastic option.  What was your approach for removal of the old valve and how difficult was it?  Also, did you change the thru hull.

Henry

I was able to remove the valve without excessive trouble.  I tried to clean up the valve to potentially reuse it but it leaks with almost no water pressure.  Now my question is the thread pattern.  Almost all the valves I see are NPT (tapered) but my thru-hull does not appear to be tapered.  Could this be BSPP threads?  Seems to be a generic valve with no brand markings.  

[cpetku]

Mine is SO40DS and the 2" valve is BPP. What I've come to believe is these require a rubber gasket to seal. While I sealed on in the rear head with pipe dope when replacing the valve, the front wouldn't seal. Tried several sizes of seals and eventually found one that worked. If too small, it compresses out of the joint when tightening. Sorry I'm not at the Marina so I can't tell you what I settled on. That said, I had a hose leak that I blamed on the valve and ended up changing the valve while in the water. It can be done, just make sure your bilge is in good order and open the new ball valve before trying to screw it onto the thru-hull. It's a little un-nerving seeing all the water coming in, so also have a plug handy. As I recall, removing the valve causes the Thru-hull to tighten. Installing the valve puts one at risk of loosening it and causing a leak. From experience, take care and don't over-do it or you'll be on the hard reseating the thru-hull. Luckily I learned this while working on the hard. Also an electric heater is your friend for softening the 50mm hose Jeanneau uses.

[henryd]

Thank you Craig.  Very helpful.  The BPP threading seems to be unusual in the US so thanks for that confirmation.  Changing it 'hot'.  That certainly does seem unnerving.  I plan to do this while still hauled.  My forward head setup seems to have been replaced already as it is Marelon and I have not paid much attention to it as I am just trying to fix the aft one.  So will look at it later.  You mentioned a rubber gasket.  Where would that go?  I am hoping to complete this without changing the thru hull, which appears to be in good shape.  That would add another whole level of complexity and certainly a lot more time.

Henry

[Charlie-Bravo]

2’ NPT has 11.5 threads per inch, BSP has 11 threads per inch, so determining which is on a through hull is just a matter of measurement with a rule, easier on the hard with the seacock removed.
There are other differences like thread angle, but these are not so straightforward to measure with general ships tools.

CB

[henryd]

Mar 6, 2024 0:18:07 GMT henryd said:

Mar 5, 2024 0:42:03 GMT Mistroma said:

Both forward and aft. heads have 2" valves. I've replaced both over the years, DZR on the forward head and TruDesign on the aft.

Forward head was easy because I was able to spin the valve on and off the elbow on the skin fitting. There's also plenty of spare hose up to the deck and down to the Jabso (no holding tank).

Aft. tank was a real pain for 2 reasons.
1) TruDesign valve is much bigger than DZR and there's not enough room to spin it around in situ.
2) Short, stiff hose section from tail to bottom of holding tank curves up sharply where it touches the hull.


I had to assemble TruDesign in place for a dry run and spin off the skin fitting from below. Then I bonded the elbow at the correct position wrt valve and bonded the tail to the other side. I assembled everything after it had set and screwed the skin fitting on afterwards from outside. Lots of sealant and 2 people needed to put it together that way.

I also had problems with the hose. It's an odd size and one supplier provided some that was just too loose. Then they provide the correct diameter but it was too stiff and wouldn't bend enough. The third lot fitted and could just bend to fit the tank outlet.

The tails are smaller than 2" and getting suitable hose to connect tail and tank might be more of a problem than you'd imagine.

Sounds complicated and I have had this type of hose mismatch issue in the past.  I will dry fit when I remove the elbow.  I have the new hose, which appears like it will fit.  I did find the exact hose they used available but would have needed to buy a roll when I only need 18".  I had to cut the old one off.  Any tips on removal of the old valve are welcomed.

Any chance you recall the exact hose size?  The nipple on the tank and elbow are marked 2" and I purchased 2" sanitation hose but it is too big.  I am thinking it is actually 50mm, which is slightly smaller but I cannot find that size hose anywhere.  $85 wasted on the 2 inch hose.  I bought enough to do both heads.

[cpetku]

Call Jeanneau america. That's where I bought hose years ago and I remember it being 50mm.

With regard to the o-rings, I tried round ones from Amazon but they tend to crush and slide out of place. I eventually ordered square profile rings from McMaster Car. I wasn't sure which size I eventually used. Here are the ones I selected.

For 2" Valves In 2022 placed orders from McMaster for:

4061T248
Square-Profile Oil-Resistant Buna-N O-Ring, 1/8 Fractional Width, Dash Number 226, Packs of 25

4061T295
Square-Profile Oil-Resistant Buna-N O-Ring, 3/16 Fractional Width, Dash Number 329, Packs of 25

I believe I settled on the 295 as it would have been less likely to pop out of the channel, but I can't tell without pulling stock on the boat (2 hr drive). They're inexpensive enough to just buy both, or use a caliper and measure the inside of your valve past the threads.



For 1" Valves (e.g., head water inlets) I appear to have used the following based upon McMaster orders in 2020. In that case I left a valve closed over winter and it froze breaking the housing.

1170N59 Chemical-Resistant Viton Fluoroelastomer O-Ring, Square-Profile, 3/32 Fractional Width, Dash No. 117, packs of 5


From Wiki:

(BSPP) 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.

Since my fittings didn't have back-nuts, I applied my favorite Soft/Serviceable compound to act as a thread lock.

[henryd]

Thanks for the information. I talked to Jeanneau about the valve (2-12 weeks) so I did not order from them. I did find a parallel thread (non tapered) valve at Defender. Still waiting for that to ship... The previous install did not have O-rings so I never considered adding them. It was only sealed with 4200 or something similar. The connections were not leaking. Sounds like I should probably add those in. Regarding the hose, I never thought to order that from Jeanneau. But what I did try was ordering some other tailpieces. I found one on Amazon where the tail is actually 2" rather than 1 7/8" so am hoping that solution works.



Henry