Groco SV Seacock Testing Prior to Installation

[endoftheroad]

My Westsail has the Groco SV bronze seacocks. I am hauling soon and barrier coating the bottom, at the same time I will be relocating my below waterline cockpit drains to above the WL. I will also be removing the remaining seacocks and thruhulls and rebuilding the seacocks before reinstalling. My seacocks don't leak but my backing plates are original and I'm not comfortable with their integrity. I have an original Groco SV 750 (3/4") stowed I a locker that I'll be installing at haul out. My question here is how do we test these valves prior to installation? Is a garden hose attached to the valve a sufficient test for leaks? Thanks, endoftheroad

[endoftheroad]

This is the SV750.
My others are mostly the 1-1/2" valves.

[HopCar]

If you're going to remove the SV seacocks and replace the backing plates, now might be a good time to replace the seacocks. The rubber plug has a limited service life as well as a limited shelf life. Groco hasn't made parts for those in twenty years.

I'd go with Groco Flanged Adapters and Groco Ball Valves.
Groco Flanged Adapter IBVF

Groco Full Flow In-Line Ball Valves (IBV series)

[endoftheroad]

Tempting.

My 40 year old Groco SV seacocks don't leak, the rubber cones are in great shape as well as the bronze. Sure they stopped making the rubber cones but they aren't that hard to come by.
I have all Groco SV's on my boat.
I believe manufacturers stopped offering these types of valves simply because of manufacturing costs, and the seepage that occurs while opening and closing the valve. Surely the mass public evolved (yeah right!) and it became unacceptable for the seepage. And it takes some strength and dexterity that might break a nail. Also you have to put your beer down for a minute.
I would consider switching to Grocos flange and ball valve system. Let's not forget that this below waterline Seacock system isn't even accepted by UL standards or whoever the official people are. Please someone clarify here for me.
So, please, everyone help me with this decision.
Why couldn't I get another 20 years? Especially since they are already on my boat and in very good condition. Yes, I will be maintaining them regularly.
I am doing a very thorough refit of my bottom, as well as replacing all the seacock backing plates which as I stated above have lost their integrity.

Is there a way to turn this thread into a vote?
I would love as much feedback as possible.

And, hopcar, I like doing business with your firm and if I go with the ball valve system I'll be sure to look you up.

So everyone.....YES or NO about reinstalling my current Groco SV valves after I replace the thruhulls and backing plates?

Thanks
endoftheroad

[endoftheroad]

Silly me!

I think it's called ABYC standards but I don't know.

I thought this topic would get some interest as the Groco valves are so common.
Heck, my wife wants to know all about this stuff.

[HopCar]

Endoftheroad, If the rubber is still good, sure you can go ahead and reuse them. They usually don't fail suddenly. It just gets harder to tighten them enough to stop drips as the rubber hardens.

The other failure mode is that on SV seacocks that are left closed, the rubber extrudes into a bump in openings. This makes it hard to open the seacock.
When this happens the rubber can tear from the handle if you try to force it. The cure for this is to disassemble the seacock and sand down the bump.

Sooner or later you'll get tired of fusing with them and replace them but there is no urgency. They're pretty good seacocks.

[endoftheroad]

Yeah,
The past 24 hours I've been leaning towards getting rid of them but I hate the short life of the ball valves. Sure they are cheap, cheap enough to carry several spares aboard.

[HopCar]

"I hate the short life of the ball valves"
I've got Apollo Conbraco Ball Valve Seacocks on my boat. They are all over twenty years old and still working fine. Good quality bronze ball valves designed for marine use, such as Apollo or Groco, should last a very long time.

When I had my boat built I had the choice of Wilcox-Crittenden traditional tapered cone seacocks, Groco SV series seacocks, or the relatively new Apollo ball valve seacocks. I chose the ball valve type and have not regretted it.

[captain58sailin]

Before you make a decision you may want to disassemble them and inspect for damage and wear. One of the things I would pay close attention to is the thru hull fitting where the straight part meets the bell that rests against the hull, I have found those with fractures all the way around at the juncture.
You might want to dye test them to insure their integrity even if you don't see cracks.

[endoftheroad]

Captain58,
Thanks for the tip.
I'm surprised I'm not getting much feedback on this thread, personally I find the subject content to be very interesting.

Although I have all SV valves in good working order I'm strongly considering the Groco flange system. If it wasn't necessary for me to replace my backing plates I'd wouldn't have the need for making this decision.

[endoftheroad]

Gotta love MaineSail's work.
Here is a stress test of the Groco Tri flange valves.

http://m.youtube.com/watch?v=KKTKQUcvU9w

I'm considering the flanged adapter/ball valve system.

Also I'm considering not thru bolting the 3 bolts through the hull and only tapping into fiberglass backing blocks. The single thruhull penetration seems sufficient. In addition to the backing blocks being epoxied to the hull.

Any comments?

[captain58sailin]

I've never tapped fiberglass so I don't know how strong it would be, if that were the choice; I would be meticulous in the installation. Maybe use epoxy on threads to seat the the bolts, or fill the holes with epoxy, and screw the bolts in before it set. I believe I would do some testing on a comparable piece fiberglass on the beach to see if I could make a strong enough coupling.

[HopCar]

I like your idea of not through bolting the seacock. I think I'd use threaded inserts instead of trying to cut threads into fiberglass. Here is a link to Suncor Stainless that shows what I'm talking about.
Thread Insert

My next statement will bring a cry of foul from the timid on this forum. I think you should use 5200 to bed the seacock flange. If ever there was a place to use 5200, installing seacocks is it. You will most likely never remove them. If you do need to remove them, it's really easy. Just warm the metal with a propane torch and they'll pop right off. Real men use 5200. That should get it started!

[westsailwill]

Few things will sink a boat faster than a failed seacock. As long as you've got them out, why not replace them? You'll sleep better at night.

[thinwater]

Originally Posted by captain58sailin

I've never tapped fiberglass so I don't know how strong it would be, if that were the choice; I would be meticulous in the installation. Maybe use epoxy on threads to seat the the bolts, or fill the holes with epoxy, and screw the bolts in before it set. I believe I would do some testing on a comparable piece fiberglass on the beach to see if I could make a strong enough coupling.

Mainesail has done his homework. I've used the same general method both on my boat and in industrial applications (chemical tanks) for 30 years. FRP can hold very strong threads. As a rule of thumb, if the FRP is 150% of the bolt dia, the stud will break or the nuts strip first.

Of course, the details are important. Degrease the stud threads, prep all bounding surfaces....