Groco SV Series Seacock Help

[Tuttouomo]

Good choice to replace with new. I had followed Angus's lead and replaced all my sea chest thru hulls and sea cocks with the Groco IBV system. That was about 5 years ago, and still really like them.

Bill

 

[angus99]

The mismatch is only an issue when threading a plain ball valve onto a thru hull without the adapter. If you use a proper flanged seacock, they've got straight threads to match the thru hull. The adapters do give you the ability to replace the valve itself more easily, however.

Damn! I think you’re right. A mind is a terrible thing to lose and I haven’t read the specs in a long time—should have checked before posting. Looking at Groco’s site, they list the female threads on the SBV series seacocks as NPS. The TH through hull series male threads are a “combination” NPT/NPSM. Not sure how they make that distinction since more than the taper is at play but I only fixated on the NPT part. Presumably, that means they’re compatible. Thanks for setting me straight.

 

[bayview]

Rubber plugs often have a nut or T handle that is used to expand and tighten the plug in place. I you loosen that the handle should turn easily

 

[mvweebles]

Okay, guys, there is a 100% consensus that I need to install new valves. I will be doing so, soon. I have plenty of real estateon the seachest wall above those two decrepit valves. I have learned here that the installation is really not that much of a big deal especially with the great access I have. Thanks so much, everyone, for taking the time to provide your insights.

One last question: what are your thoughts on installing them while in the water. I can glue the backing plate in place, get the flange ready to bolt to the plate with the ball valve mounted, drill the center hole for the water intake, and quickly, very quickly bolt the assembly to the backing plate. Crazy idea?

I know you will do it on the hard, but question for you : your sea chest is pretty deep. Could you physically reach the mushroom fitting even if doing in the water? Just curious

 

[catalinajack]

Yeah, pretty much I am able to reach far down inside the seachest, certainly as far as the old seacocks.

I know you will do it on the hard, but question for you : your sea chest is pretty deep. Could you physically reach the mushroom fitting even if doing in the water? Just curious

 

[angus99]

catalinajack and I have virtually the same boat. I replaced my through hulls/seacocks while the boat was hauled. With the cover off the seachest, I could reach all the through hulls from the top.

 

[mvweebles]

BTW - I have total sea chest envy. Total boat porn.

Peter

 

[HopCar]

When an SV series seacock is left in the closed position, the rubber expands into the opening and eventually a bump forms. This bump prevents it from easily turning. Some people would sand down the bump to make it easier to turn. You can try that but your seacocks are so old I really recommend replacing them. The rubber is probably really hard and brittle by now.

 

[angus99]

When an SV series seacock is left in the closed position, the rubber expands into the opening and eventually a bump forms. This bump prevents it from easily turning. Some people would sand down the bump to make it easier to turn. You can try that but your seacocks are so old I really recommend replacing them. The rubber is probably really hard and brittle by now.

Hi, Parks. Still living large off my investment in your company (Post 21)?

Seriously, hope all’s good.

 

[HopCar]

Hi, Parks. Still living large off my investment in your company (Post 21)?

Seriously, hope all’s good.

Thanks to you I’m living the high life!

 

[catalinajack]

Based on the several opinions expressed here I will be doing so. Of the two that I have that remain in service, one is the feed to the raw water wash down pump. That valve is very difficult to turn but is not critical to the operation of the boat.

The other serves one of the two generators on board and still works fairly well. I will use the new seacock for the generator and use the old, decent SV valve for the wash down, at least for the time being. Those Groco fittings are not inexpensive.

When an SV series seacock is left in the closed position, the rubber expands into the opening and eventually a bump forms. This bump prevents it from easily turning. Some people would sand down the bump to make it easier to turn. You can try that but your seacocks are so old I really recommend replacing them. The rubber is probably really hard and brittle by now.

 

[FF]

A bronze seacock , if left closed will grow life on the exposed portion of the plug.

Once a month or so its nice to operate the valve a few times.

Happily a quality seacock can be operated with a cable , a repurposed shift and throttle control is fine for the purpose.

 

[ProMaritime]

Heck, when I saw this post I hoped someone would know where to buy the rubber bungs and molded bronze fitting for the handle. I have five of them on my boat and a couple of spares that I installed almost 40 years and and I baby them like they were gold because they are the gold standard for seacocks.

I remove, clean and reassemble them a couple of times a year. This is easy to do with the boat in the water. Back the compression screw on the seacock all the way off. Remove the two screws on the bronze ring that holds the bung in the body of the unit. Remove the bung. Yes, water will spray all over the place so wear a swim suit and have a large rag handy to stuff in the hole. You can completely stop the water flow by pressing the rag into the hole and clamping it there with a C or bar clamp. Then clean and re-grease the bung, pull out the rag and press the bung back in with the bung's hole aligned as if the unit was in the open position. Make sure that the pressure plate is seated flat against the back of the unit before attempting to reinstall the bung. This is the most difficult part because water is now rushing back into the boat.

I have both 1&1/2" and 3/4" Groco seacocks with no through-hulls. Yes, no freaking through-hulls to cause problems. I installed them originally using the seacocks as patterns to drill holes through the hull the diameter of each seacock and holes 3/8" to install two studs for each seacock. The studs were counter sunk in the hull from the outside. I built up pads of fiber glass about 3/4" thick and 8-9" in diameter at each location on the inside of the hull. Using a slow catalysis the glass was saturated and each seacocks dropped in turn on to their studs. Nuts were torqued down on the studs and the seacock was pressed into the wet glass. The recessed hex-head machine screws used as studs were glassed into their recesses and fared with the outside of the hull, thus eliminating the need for trough-hulls. Once the cured the glass pads had sealed the seacocks tightly to the hull. It was necessary to grind out the glass obstructing the seacocks. A Dremel with a course sanding drum did this job quickly.

Now I can easily Dremel out any growth and old bottom paint inside each hole during a haul-out and apply bottom paint way up to the seacock itself. And the seacock are doubly secured by being glassed to the inside of the hull and mechanically fastened to the outside by the studs. On a haul-out about 20 years later I discovered one 3/8" stud on one of the five seacocks broken due to crevice corrosion but the seacock didn't leak of even budge. It was simple to replace and re-glass.

My boat, built in 1969, has a solid glass hand lay-up hull to deck level. To use this technique on today's boats which may have totally cored hulls or even if they are solid glass to the waterline might require an engineering review.

 

[Frosty]

I have both 1&1/2" and 3/4" Groco seacocks with no through-hulls. Yes, no freaking through-hulls to cause problems.

What problems do through hulls cause that an unadorned hole in the boat doesn't? Not "challenging" you but just haven't experienced it or don't know what I'm missing?

(BTW I did have a fiberglass early 60's boat that had bronze seacocks bolted through the hull and no through hull fittings. I liked the seacock installation but never really thought of the lack of through hulls as a particular advantage.)

 

[FF]

Using a sea cock with no thru hull exposes the hull to worms if wood ,
and the edges of the laminate to water intrusion if GRP.

AS a thru hull can be removed and inspected with little effort , the sea cock is not bothered, they do offer some hull protection.

 

[HopCar]

I agree with FF. The thru-hull fitting protects the end grain in both wood and fiberglass. They also make the installation stronger.

 

[ProMaritime]

This why I mentioned that my boat's hull is a solid glass not a cored hull. Each seacock discharge hole was liberally coated inside with an epoxy barrier from the outer surface of the hull to the bottom mounting flange on the seacock.

 

[Waywego]

For a dissenting opinion...

We have the Groco SV seacocks on our 45 year old boat. When we got the boat, they were pretty much stuck in position and I considered replacing them. At our first haul out, I disassembled them, lightly sanded the bumps, greased them with silicone grease and reassembled. They have been flawless for the last 5 years. We are currently on the hard and they will get another R&R before launching.

My point is that you might inspect them before automatically replacing. The only downside to them is that it is a two step process to change positions of the lever because you need to loosen the lock screw first, move the lever and then tighten the lock screw.

 

[HopCar]

For a dissenting opinion...

... The only downside to them is that it is a two step process to change positions of the lever because you need to loosen the lock screw first, move the lever and then tighten the lock screw.

Sounds like you’ve already figured it out but for those who haven’t., don’t over tighten the lock screw. It makes the bumps bigger faster.

 

[Waywego]

Sounds like you’ve already figured it out but for those who haven’t., don’t over tighten the lock screw. It makes the bumps bigger faster.

Another thing that I have found that helps is to periodically turn them to the position you don't normally have them in and leave them with the lock screw tightened. This seems to compress the bumps somewhat.

 

[catalinajack]

I am the original poster. It has become apparent that replacing these valves may not be necessary, that removing the rubber plug and renewing the surfaces may bring it back to close to original along with some grease. Given the expense of replacing them, it seems a good idea to at least give it a try. I have two of these valves in service. I have given them some exercise and both have become less difficult to move. What I do not have is a reference point. I do not know how much resistance a well-functioning SV valve should have. To the responders who do have "good" valves, do you have any insight for me?

In addition to the two SV valves that I have in service, I have two others on the sea chest that were capped long ago. Then, there are two through-hulls below the water line, one unused, the other for black water discharge. There are three more for discharge above the water line for bilge water discharge. These stay open. In fact, I do not understand why a valve is even needed for bilge water given that, at least on my boat, the three ports for air conditioning sea water are not valved.

 

[Waywego]

If the lock is properly loosened, the valve should be fairly easy to turn. Perhaps not quite as easy as a good ball valve, but not that much harder.

While in the water, there is some improvement that can be made, but disassembly while hauled is certainly better. If you can close the valve and remove any fittings, you should be able to put some silicone grease on the rubber cone from the open hole. Once you reinstall the fittings, if any, and attach the hose, you can exercise the valve and distribute the grease. I have found that helpful in winters that we do not haul our boat.

While I would prefer some new ball valves, at the cost to buy them, I am happy to keep my Groco SV's working longer than the 46 years they have already been in service.

 

[Frosty]

There are three more for discharge above the water line for bilge water discharge. These stay open. In fact, I do not understand why a valve is even needed for bilge water given that, at least on my boat, the three ports for air conditioning sea water are not valved.

Is the bilge pump through hull below the dynamic water line? If so that may be why.

 

[catalinajack]

I don't know what is a "dynamic" water line but the through-hulls I am talking about are at the same level as my three A/C seawater discharge ports which are not valved.

Is the bilge pump through hull below the dynamic water line? If so that may be why.

 

[Frosty]

I don't know what is a "dynamic" water line

It's what you could call the heeled waterline. In other words parts of the boat that may be below the waterline underway vs. at rest. I believe 7º is considered the standard heeled amount for powerboats (obviously it's greater for sailboats).

 

[catalinajack]

Thanks, Frosty. If my boat heeled over to get to the discharge point I would have more to worry about than a bit of water backing into the bilge output. I suppose if I were rolled by a big wave on the beam I might briefly have those discharge holes under water but it would not be an issue.

It's what you could call the heeled waterline. In other words parts of the boat that may be below the waterline underway vs. at rest. I believe 7º is considered the standard heeled amount for powerboats (obviously it's greater for sailboats).

 

[Frosty]

Fair enough. You had mused about why the bilge pump outlet had a valve, and I thought that might be the reason. Since "technically" the dynamic waterline is mentioned as a dividing point. I didn't mean to imply you should set your boat up that way though. (I imagine it already has a siphon break if appropriate.)

 

[catalinajack]

Fair enough. You had mused about why the bilge pump outlet had a valve, and I thought that might be the reason. Since "technically" the dynamic waterline is mentioned as a dividing point. I didn't mean to imply you should set your boat up that way though. (I imagine it already has a siphon break if appropriate.)

Frosty, yes, your observation was good food for thought. No siphon breaks though on above water line holes. A side benefit of these old valves is the one used for the overboard black water discharge. In no discharge zones, we all know of the Coast Guard requirement that the discharge is locked out in some manner. These valves are locked with the t-handle, open or closed. We have been boarded by the CG just once. I was asked how we comply with this requirement. I demonstrated the t-handle. A-OKAY.

 

[ranger58sb]

I am planning on paying Groco a visit soon, in person. They are located on Kent Island (MD) where the boat will be soon relocated.

What? You're moving? Where?

-Chris

 

[catalinajack]

Yesterday, we moved the boat from Hartge on the West River to Piney Narrows Yacht Haven on Kent Island. We already like it better. Infrastructure (shopping, services, restaurants) more of them and closer. Paved parking lot with assigned space, large pool, 25-cent per gallon fuel discount, washing machines and heads just steps away. It was my first time single-handing this somewhat large boat (DeFever 44). Uneventful 3-hour cruise although the bay was rather unkindly until I rounded Love Point and headed north. My first mate was waiting for me at the new berth.

What? You're moving? Where?

-Chris