Groco vs Conbraco Valves...

[Sailorguy]

I installed GROCO BV Series Full Flow Ball type sea cocks: the ball and stem are 316 SS and the body is bronze casting. Others that I had talked to that had installed chrome plated bronze ball valves such as Apollo brand had reported pitting which caused leakage.

Steve

[Sailorguy]

Add'l comments: the Groco full flow "inline" type valves use a chrome platted brass ball; these are designed to screw onto a thru hull vs. the sea cock which is designed to be thru bolted. I would rec'd staying away from the inline version. The sea cock adds a level of security and longevity not found in the other....IMHO.

Steve

[Maine Sail]

Originally Posted by Sailorguy

Add'l comments: the Groco full flow "inline" type valves use a chrome platted brass ball; these are designed to screw onto a thru hull vs. the sea cock which is designed to be thru bolted. I would rec'd staying away from the inline version. The sea cock adds a level of security and longevity not found in the other....IMHO.

Steve

I understand many are not aware of the flanged adapter. Inline BV's do not have to thread only onto a thru-hull, in fact doing so is usually a thread mis-match. Inline valves can be threaded onto a flanged adapter too.

Below is a flanged adapter:




P.S. I have two flanged Apollo seacocks that were installed in 2000 for my cockpit scuppers. They have stainless balls and are very tough to operate at this tiem and lube has done noting to help. These are my final two non-flanged adapter seacocks.. I will be replacing them this winter with Groco flanged adapters so that in another ten years I am not doing major surgery to replace the valves..


Hope the photo helps show how a flanged adapter works.

[cburger]

Ditto that Steve

[Cheechako]

My concern with the threaded "take apart" version would be that it is no different than just putting a ball valve on the stem of a thru hull...... the stress in trying to open/close a frozen valve is still on the threads (thinnest part of the assembly) rather than on the triangular base.... With a normal seacock it is distributed to the base.....
Not sure what Groco is doing now days. They never were as good as Wilcox Crittendon, who no longer exist. Groco is chinese now arent they? The real question is are they controlling their quality well enough if chinese? or living off their name? The key to Chinese quality is setting an expectation of what you want and monitoring it until they "get it". If Groco is not doing Mettalurgical analytic samples... who knows what the stuff is.... Spartan stuff is still made in the NE US isnt it? I would definitely give them a look.... They make some nice stuff.

[cburger]

Originally Posted by Cheechako

My concern with the threaded "take apart" version would be that it is no different than just putting a ball valve on the stem of a thru hull...... the stress in trying to open/close a frozen valve is still on the threads (thinnest part of the assembly) rather than on the triangular base.... With a normal seacock it is distributed to the base.....
Not sure what Groco is doing now days. They never were as good as Wilcox Crittendon, who no longer exist. Groco is chinese now arent they? The real question is are they controlling their quality well enough if chinese? or living off their name? The key to Chinese quality is setting an expectation of what you want and monitoring it until they "get it". If Groco is not doing Mettalurgical analytic samples... who knows what the stuff is.... Spartan stuff is still made in the NE US isnt it? I would definitely give them a look.... They make some nice stuff.

All very good points, Spartan high quality yankee construction.

[s/v Jedi]

Okay, I am convinced... see, I change my mind sometimes ;-)

Now the only possible problem left is when you get a valve or thru-hull fitting with that nasty British thread, BSP or whatever they call it. Many valves sold in places like Trinidad have that....

Edit: no guys, I think Mainsail found that the wall thickness of the flanged adapter equals that of a seacock.

cheers,
Nick.

[Maine Sail]

Originally Posted by s/v Jedi

Edit: no guys, I think Mainsail found that the wall thickness of the flanged adapter equals that of a seacock.

cheers,
Nick.

Yup! Theories are good but I always do the dirty work..



For this examination I wanted to know the actual wall thickness of a standard 1" thru-hull fitting. The fitting is a common bronze Conbraco/Apollo 1" thru-hull which I purchased right off the shelf at Hamilton Marine.

In this photo I am measuring the overall thickness of the thru-hull.
It measured in at 2.99 millimeters thick.



To accurately measure the nominal wall thickness of this 1" thru-hull I first needed to measure the thread depth that had been cut into it. I used my calipers to figure out the depth of the thread cut.


The threads cut into the the 1" thru-hull pictured above were 1.45mm deep on that 1" thru-hull fitting.

If you subtract the 1.45mm thread cut from the 2.99mm overall thickness you get the remaining nominal wall thickness of 1.54 millimeters.

Yes, you read it correctly, the nominal wall thickness on this very popular Apollo 1" bronze thru-hull fitting is roughly the thickness of an average penny at only 1.54 millimeters.




In the interest of fairness I also wanted to measure the total wall thickness of the flange, at the top threads, to compare it to the 1" thru-hull nominal wall thickness. I understand I'm not comparing two 1" or two 3/4 inch fittings but the points remain the same and the wall thickness is what I am trying to get at. This3/4 flanged adapter fitting measured an overall thickness of 4.04 millimeters and a thread depth of 1.26mm millimeters. When you subtract 1.26mm from 4.04mm you are left with a total nominal wall thickness of 2.78mm. This makes the thickness, of this 3/4 flanged adapter fitting, at the threads, approximately double that of the 1" Apollo thru-hull fitting, and comparable to the base thickness dimension of a Groco flanged seacock.


In short the flanged adapters are quite robust..

[Cheechako]

I like the science and it seems to indicate that they thought about this.... which is very encouraging in these days and times!! However, we can only conclude that in order to get the wall thickness, you now have a 1" thru hull with the inside diameter of about a 3/4" thru hull!..... which is still better than haveing a thickness of a penny I suppose....

[barnakiel]

I will need new ones too. I like bronze but hard to find/get here (EU).

SS good ?

Vetus makes them.

barnie,

[Christian Van H]

Originally Posted by barnakiel

SS good ?

NO. No stainless steel below the waterline, imho.

[s/v Jedi]

Barnie,

In which country are you?

cheers,
Nick.