technical problem for water inlets

[flysofia99]

here are water inlets for air condition cooling water and generator cooling water , corrosion is always very fast ,.some days later, will find a lot of salt on it?is it a big problem? is there any solution for.that?

[flysofia99]

sorry I send it too fast，forget to say thank you。

I am preparing the boat for sailing，buy this second hand lagoon 440
this July，then I find this problem。

does anyone know this？ is it a big problem？

my english is not good，hope I explain it well enough

[downunder]

This is a well known problem with Lagoons and other european vessels.

Fitting cheap brass seacocks with limited life. You need to replace the seacocks quickly before they fail preferably with bronze or Carleton.

There is significant discussion on this issue if you search older threads on this site.

Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Compass Marine How To at pbase.com

[flysofia99]

Originally Posted by downunder

This is a well known problem with Lagoons and other european vessels.

Fitting cheap brass seacocks with limited life. You need to replace the seacocks quickly before they fail preferably with bronze or Carleton.

There is significant discussion on this issue if you search older threads on this site.

Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Compass Marine How To at pbase.com

--------------------------------
that really helpful. thank you a lot.

do you find the under party mine is already change to blue or dark blue

does it mean the problem already very serious?

I need change it right now, or it could wait a little.

because now the boat is in the water,I think maybe I need repair it when lift out，yes？

[Captsteve53]

Replace it ASAP this is a disaster ready to happen, the present valve is not a marine valve (it's a house type ball valve),there's plenty of posts recently on this very subject, go with a Marine certified sea cock or one of newer type composite vales from Trudesign as
:Marine | TRUDESIGN
Note: It is feasible to replace sea cocks in the water and done so more often than one cares to think about, you can just bang in a wooden plug on the outside of the hull fitting and do your replacement of the valve, that being said it's very hard (if not impossible ) to find a correct marine certified BALL valve , that said AGAIN any full BRONZE ball valve will be safer than what you have now!( AT LEAST TEMPORARY)

Points From my earlier post

1)Approved sea cock composite materials include glass-reinforced, UV-inhibited nylon such as acetyl and polybutylene terephthalate. Tru-Design, manufactured in New Zealand ), is one example of (Marine | TRUDESIGN) an excellent non-metallic, UL-approved below-the-waterline sea cock assembly material. A note of caution: Be sure that your boat’s sea cocks and through-hull fittings, whether metallic or composite, carry the UL approval number 1121 or 618C for “marine through-hull fittings and sea valves.” Where sea cocks are concerned, not just any UL approval will do. Many valves carry UL approval for other uses, but only those that carry the “sea valve” approval are truly UL approved for this application.

2)Unapproved sea cock and through-hull fitting materials include the previously mentioned high-zinc-content brasses and stainless steel, the latter being susceptible to crevice corrosion when used in below-the-waterline applications. Additionally, chrome- or nickel-plated brass, which has a silver appearance and is often mistaken for stainless steel, suffers from the same failings as ordinary brass and thus must never, be used in sea cock, raw-water, or through-hull applications. Plastics such as PVC (regardless of “schedule”) and other non-reinforced, non-UV-inhibited, non-metallic materials, while fine for domestic plumbing and non-overboard discharge sanitation plumbing, have no business being used in sea cock and below-the-waterline raw-water applications.

3)In order to gain the highly desirable UL and ABYC approvals, a seacock must possess a lever that arcs through 90 degrees of travel—no more and no less—to open and close the valve. This makes operation easy and quick and provides a clear indication, even from a distance, of whether the valve is open or closed.

4)Finally, and perhaps most importantly, “please” don’t confuse an inline ball valve with a true seacock. Inline ball valves, which lack a load-distributing flange, are neither appropriate for use as sea cocks nor designed by their manufacturers to be used in this manner. They may be UL-approved “valves,” but they are not designated by UL as “sea valves.” In addition to lacking a flange, inline ball valves utilize NPT or tapered threads, while purpose-made sea cocks use straight or NPS threads. The latter allow full engagement of the like-threaded through-hull fitting—as many as eight or 10 threads—while the ball valve will engage only two or three of the straight through-hull threads. It’s worth repeating, as this is among the most common seacock installation faux pas I’ve witnessed in my 40 years in the marine industry: inline ball valves are not designed to be used as sea cocks.

Cheers Steve

[Kenomac]

You need to change that out asap along with the rest of them. I'd recommend Forespar Marelon seacocks, no issues with ours since 2002. Plastic can't rust. While you're at it, take a very close look at the skin/through hull fittings which are most likely made of brass. They'll need to be changed out at the same time. Better to get it over with and not have to worry, and a relatively easy but time consuming task for two people during a haul out. Plan on cutting off the through hulls using a Fein tool.

"Marelon is a proprietary formulation of polymer composite compounds using composite polymer resins and additives to produce a superior marine-grade product. Forespar continues to expand their product range with a series of accessories."

[HopCar]

The valve and elbow appear to be made of DZR Brass (dezincification resistant brass) the thru-hull fitting may be as well. This material has a useful life of between 5 and 10 years in contact with salt water.

On top of the cheap metal, the installation is very weak. The threads in the valve are tapered and the threads on the thru-hull are straight. The valve will only screw onto the thru-hull a couple of threads. Also with that much unsupported thru-hull, it would be pretty easy to snap it off. I don't see a backing plate either.

I would replace the whole setup with a bronze thru-hull and a proper flanged seacock valve. Groco or Apollo are two brand names I trust for this type of hardware.
https://www.groco.net/products/valve...lves/bv-series

[TKDSailor]

We have a steel hulled ketch, and can not use bronze or brass. A Marlon (plastic) valve solve our problem. We have never had a problem with it (one large valve leading to a sea chest). Best of luck to you!

[mitiempo]

Originally Posted by Captsteve53

4)Finally, and perhaps most importantly, “please” don’t confuse an inline ball valve with a true seacock. Inline ball valves, which lack a load-distributing flange, are neither appropriate for use as sea cocks nor designed by their manufacturers to be used in this manner. They may be UL-approved “valves,” but they are not designated by UL as “sea valves.” In addition to lacking a flange, inline ball valves utilize NPT or tapered threads, while purpose-made sea cocks use straight or NPS threads. The latter allow full engagement of the like-threaded through-hull fitting—as many as eight or 10 threads—while the ball valve will engage only two or three of the straight through-hull threads. It’s worth repeating, as this is among the most common seacock installation faux pas I’ve witnessed in my 40 years in the marine industry: inline ball valves are not designed to be used as sea cocks.

Cheers Steve

Tru-Design excepted. Their collar system is excellent, not expensive, and their valves are in my opinion superior to Forespar's valves. They have to be installed as a completes system - through hull, valve, and collar - as their threads are not compatible with other products.

[Suijin]

AND don't mix metals in your fittings, like putting brass onto bronze. Not good.

CaptSteve summed it up pretty well.

I like Marelon through hulls, but not anywhere where they might get kicked or knocked. They are probably plenty tough enough but there's a little voice in the back of my head that whispers "plastic...".

[HopCar]

Originally Posted by mitiempo

Tru-Design excepted. Their collar system is excellent, not expensive, and their valves are in my opinion superior to Forespar's valves. They have to be installed as a completes system - through hull, valve, and collar - as their threads are not compatible with other products.

I agree, if you are going to use plastic on this critical application, Tru-Design is better than Marlon. Tru-Design is distributed in the US by Raritan.

[constellationms]

Because the outcome, it is collective for inlet controllers to practice problems over time. Maybe the most generally faced problem is that of a circumscribed water flow. You can directly contact to our experts.

[rourkeh]

If this is the quality of the through hull fittings and installation from the factory on a production boat just imagine the attention to detail on the rest of the boat, specifically the things you cannot see. Nice.

[Bleemus]

I remember the first time I saw this on a Lagoon and my jaw hit the hull when he said it was factory. Shocking.