Greasing a standard ball valve seacock...

[Iain C]

I changed my heads out seacock in the spring...it's a gravity holding tank setup and the old one was knackered. In my haste to get it done...between tides...and also antifouling...I may have forgotten to grease it, and it is now intermittently pretty stiff.

What's the best grease to use, and is it a simple case of just poking it up the hole? (oo-er)

Thanks

 

[prv]

If it's a typical ball valve with a teflon seat, it does not require or benefit from greasing. In fact there's a suggestion that some greases can cause the seat to swell and jam.

Exercising the valve regularly will wipe off marine growth and debris from the surfaces of the ball lined up with the pipe, and help stop it getting jammed that way.

Pete

 

[Yngmar]

Prv is right, most good ones do not need greasing. But if you want to, silicon grease is harmless to PTFE and thick enough to be injected from the exterior onto the closed ball (put it in a plastic syringe) while in the water. Have someone exercise the lever a couple times and job done.

 

[johnalison]

We were discussing sticky valves some years ago nad the general feeling was that valves stay in better condition if they are left open, when the crud that develops only adheres to the lining and not the bearing surface. This is not particularly helpful advice when there are seacocks that one wishes to leave shut, but exercising regularly is good for seacock health.

 

[Heckler]

I changed my heads out seacock in the spring...it's a gravity holding tank setup and the old one was knackered. In my haste to get it done...between tides...and also antifouling...I may have forgotten to grease it, and it is now intermittently pretty stiff.

What's the best grease to use, and is it a simple case of just poking it up the hole? (oo-er)

Thanks

I half close the valve so so half the ball is exposed to the passing fluid and then put the chosen lubricant through the outlet.
Then work the valve a few times to smear it over the working surface

 

[Tranona]

The 1 1/2" valves are inherently stiff to operate even when new. often not helped by the handle being in an awkward position. As suggested just operate regularly to reduce the chance of crud build up at the external side of the opening.

 

[reeac]

During the 12 years that I owned my Sadler 29, I religiously dismantled, cleaned and greased the Blakes seacocks annually but did nothing to the engine cooling water ball valve. Never had any problem with either but it made me wonder about the merits of the two designs.

 

[Iain C]

Thanks all. It was fine when installed but got steadily worse...however this year seems to have been terrible for fouling so perhaps that's my problem. Ill give it a good blast with the HP hose when I scrub off this weekend and if that sorts it job done.

As Tranona points out (presumably from his own Bav experiences) the handle is in a total pain in the ass place which is probably half the problem!

 

[vyv_cox]

The ball in ball valves is made of brass, either chromium or nickel plated. This applies even to bronze bodied valves but I believe not to DZR ones. Over time the brass corrodes and the plating pits at first, then spalls off. Ultimately a common consequence is that the stem, which also corrodes due to dezincification, breaks when the handle is turned due to the high frictional load. There are photos illustrating this at the bottom of this page http://coxeng.co.uk/metallurgy/brasses-and-bronzes/

 

[ghostlymoron]

Surely the ptfe or whatever seal will squeegee any grease straight off again.There cant be any gap between ball and seal or it would leak so no point in attempting to lubricate I'd say.

 

[Kukri]

The ball in ball valves is made of brass, either chromium or nickel plated. This applies even to bronze bodied valves but I believe not to DZR ones. Over time the brass corrodes and the plating pits at first, then spalls off. Ultimately a common consequence is that the stem, which also corrodes due to dezincification, breaks when the handle is turned due to the high frictional load. There are photos illustrating this at the bottom of this page http://coxeng.co.uk/metallurgy/brasses-and-bronzes/

+1. damhikt.