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-   -   "Seacock" vs. "ballcock" or "ball valve?" (http://www.sailnet.com/forums/gear-maintenance/45368-seacock-vs-ballcock-ball-valve.html)

SEMIJim 07-27-2008 12:21 AM

"Seacock" vs. "ballcock" or "ball valve?"
 
I've been using the words "seacock" and "ballcock" interchangeably. Earlier today, while looking something up, I noticed here that maybe the words aren't interchangable? The seacocks they show here and the ball valves (aka: "ballcocks?") they show here. In fact: On each page there is a series of Groco valves that look nearly identical and have very similar part numbers.

So what is the difference, if any, between a seacock and a ball valve or ballcock, other than the fact that it would appear most seacocks have flanges?

Our boat currently has a kind of a haphazard raw water hookup. (You can kind of see part of it in Good Source For Hose Fittings.) There's a 3/8" thru-hull (with scoop strainer). That is stepped up to a 1/2" fitting, to which a... well, I guess it's more properly a ball valve, attached. Then there's a right-angle 1/2" NPT hose barb atop that, that has a 3/8" barb (looks like). That last will soon be changed to a 1/2" NPT "full flow" barb as part of the raw water strainer addition. I may get ambitious after this seasons haul-out and change the thru-hull to 1/2", but I was figuring on just re-using the existing ball valve, since it appears to be working well. (That change is very low priority, since the raw water cooling seems to be keeping our boats venerable old A4 happy just as it is.)

Jim

trantor12020 07-27-2008 05:59 AM

maybe ball valves is the politically correct name for seacock especially these days there are more lady sailors than back in days of .... '60s ?

Maine Sail 07-27-2008 08:09 AM

Jim,

Definitions are hard to garner when it comes to seacocks. Here is my best interpretation of it from ABYC.

Proper Seacock= A tapered cone or ball valve type valve with a handle that rotates only 90 degrees that also has an integral flange. Whether this is on or off the boat it is still called a seacock as that is its only designed purpose.

Ball Valve = This is still called a ball valve until you install it on the top of a flanged adapter or a thru-hull fitting then it becomes a seacock. While it is not a seacock in the "proper" sense any valve that penetrates the hull becomes a seacock if it meets the 90 degree handle rotation definition set forth in ABYC H-27.

Ballcock = This is a plumbing term used by the plumbing trade and only defines the style of valve as a "ball" type "****". The words "****" or "valve" are indeed interchangeable. However there are many types of cocks such as sillcocks, which can also be of the ball type, and petcocks, which can also be of the ball type. Ballcock is not a term generally used on boats but is not necessarily wrong unless you are talking to someone in the marine trade who is expecting to hear the term seacock and you are saying ballcock which could indicate a valve not attached to the hull.


As for your other question on another post:

From ABYC H-27

"27.2.2 Threads used in seacock installations must be compatible. (e.g. NPT to NPT, NPS to NPS)"


I think this is pretty clear wording and clarifies that many of the installations currently out there, including your engine intake, do not meet the current ABYC safety standard for a seacock installation.



Properly flanged seacocks or the use of flanged adapters or matched threads and the ability to withstand a 500 pound static load at the most inboard portion of the assembly (usually the hose barb) are the only installations that will meet the current ABYC H-27 safety standards. If you feel comfortable that the mis-matched threads and valve could hold a 500 pound static load at the innermost hard fitting on the valve assembly then you're good to go..

SEMIJim 07-27-2008 08:44 AM

Thanks for the clarification, Hal. That, along with your Seacock & Thru-Hull Primer/Pre Information page clear it up nicely for me.

Looks like our "seacocks" need to be re-done. I'll add that to the list.

While we're on the subject: How does one go about securing an adaptor flange?

Jim

Maine Sail 07-27-2008 12:16 PM

Hamilton Marine 3/4" Flanged Adapter

Hamilton Marine 1" Flanged Adapter

Hamilton Marine 1.25" Flanged Adapter

Hamilton Marine 1.5" Flanged Adapter


West Marine and Defender also carry the Groco flanged adapters.

IBVF- 750 = 3/4"

IBVF-1000 = 1"

IBVF-1250 = 1.25"

IBVF-1500 = 1.5"

SEMIJim 07-27-2008 11:07 PM

LOL! No, Hal, I was wondering how one actually secures those flange adapters to the hull, not how one goes about securing ownership of them. :)

Btw: I noticed Groco has 1/2" thru-hulls, ball valves and hose adapters, but no 1/2" seacocks or IBVF-series adapters. I've sent them an email asking them why that is.

Jim

sailaway21 07-28-2008 01:14 AM

Quote:

Originally Posted by SEMIJim (Post 346654)
LOL! No, Hal, I was wondering how one actually secures those flange adapters to the hull, not how one goes about securing ownership of them. :)

Btw: I noticed Groco has 1/2" thru-hulls, ball valves and hose adapters, but no 1/2" seacocks or IBVF-series adapters. I've sent them an email asking them why that is.

Jim

Jim,
A lot of boats are not able to screw the mushroom male portion of the thru-hull into the seacock or use a locking/compression nut on the thru-hull due to curvature of the hull. The curvature inside does not always match the curvature outside. What is commonly done is to place the thru-hull in a relatively flat spot on the hull exterior and then make up a wedge to back it within the boat. That way you get a good square fit to the thru-hull regardless if it attaches to the seacock or the compression nut.

What is commonly done, and it's not a bad idea even if the thru-hull passes through perfectly perpendicular to the hull, is to epoxy in a backing plate of marine plywood or even a piece of teak would work. You frame up a mold, for temporary use, and then your wood goes over the top of it. Mix the epoxy with an additive for strength and inject the epoxy into your mold (just dump it in and slap the wood on it) thereby bonding the wood to the epoxy and the hull. You can go overboard and even lay fiberglas over the new fairing thereby encapsulating the wood. Now you have the wood to secure your flanged adapter into with wood screws.

Edit: I just remembered an easier way to do the above. Take a can of baked beans and put the beans on to simmer with a dollop of brown sugar in them. Clean out the can and fill it an inch or so deep with thickened epoxy. Set it someplace where the fact that the can is going to get pretty warm does not matter and go eat your beans. About the time that the beans have passed through your system and are doing what beans do you can go outside, you're gonna have to anyway (!), and cut the bottom out of your can. You'll now have a very nice hockey puck that you can sand to fit the angle of the hull. Cut a piece of wood to fit the top of it and epoxy and clamp in place. Drill the correct size hole through it and install as below. by now the gaseous condition should have moderated and I'd say you're ready for ice cream!

You've also thickened the hull in the area of the thru-hull, never a bad idea, and you've created a deeper hole to fill with sealant when you install your thru-hull resulting in greater longevity to the seal with less potential for a leak.

If the hull where your thru-hull goes is pretty flat, inside and out, you can do all this much easier. Paint the plywood with epoxy after you've drilled a hole in it the size of the thru-hull. Then use thickened epoxy to secure the plywood to the inside of the hull. You can take your thru-hull and put it through the hull temporarily and use it with the compression nut to clamp the wood down until the epoxy sets. Then disassemble and mount and seal the thru-hull in the normal fashion. Again you now have a nice piece of wood to secure the flange upon.

Maine Sail 07-28-2008 08:21 AM

Quote:

Originally Posted by SEMIJim (Post 346654)
LOL! No, Hal, I was wondering how one actually secures those flange adapters to the hull, not how one goes about securing ownership of them. :)

Btw: I noticed Groco has 1/2" thru-hulls, ball valves and hose adapters, but no 1/2" seacocks or IBVF-series adapters. I've sent them an email asking them why that is.

Jim

Silly me..!

You can through bolt them, as I do, or drill & tap a fiberglass backer block or drill and screw some bronze lags into the marine ply backing plates. Be sure to use bronze bolts, screws or lags for "securing"!!!

While screwing is not as strong as through bolting it is still MUCH stronger than what you have now and perfectly acceptable if you're not comfortable with a through bolted installation..


Through bolting prior to fairing the holes over...
http://www.pbase.com/mainecruising/image/91173865.jpg

SEMIJim 07-28-2008 09:03 AM

Got it, gentlemen. Thanks for the help!

Jim

sailortjk1 07-28-2008 12:22 PM

I see we have gone PC even when it comes to typically used terms in the Marine industry. What next?


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