Dry Fitting Groco Ball Valves... Quick Q.

[sharpey]

Hey all,

Just not sure if I'm "doing it right"...

I've got a 3/4 inch setup from groco that I'm going to install...

The throughull screws into the flange nicely... no isues there... nps to nps threads...

The issue I'm facing is that the ballvalve connection to the flange, and the hose-barb connection to the ballvalve don't seem to let me tighten down through all the threads... this is a bit odd, as it does seem that there are enough female threads on both... I've put them together as tight as possible with a couple of spanners... and at least on the hose fitting, there's still 3 threads left... I don't know if I'd be able to tighen it so much once installed on the boat! The force required is tremendous!

Any advice/hints most appreciated.

Cheers,

James

[Blue Stocking]

Thru-hull to flange are parallel threads, the ball valve is probably tapered thread.
Are all parts Groco?--their info is available on site on line.

[sharpey]

yup.... the throughull and the flange are fine... nice and smooth...

its the npt to npt threads that seem to get too tight, too quick...

Mind you, I'm a total beginner at this... so I'm prepared to admit that what I'm experiencing is totally normal...

All parts are genuine groco from a reputable dealer.

[Badsanta]

You need a groco flange adaptor. The thru hull has streight threads not to be confused with tapered threads. You should not put tapered into streight threads or visaversa check groco for explanation.

[sharpey]

sorry if I didn't make it clear... I do have the flange adapter...

Total 4 piece set...

1 throughull
1 flange adapter
1 ball-valve
1 hose barb


it's the connections between the barb & valve... and between the Valve & adapter that I'm questioning...

Cheers

[Badsanta]

I would contact groco. I found them very helpfull.
When I installed mine it went very easy. I dont know what to add.
When I did mine I installed the flange adaptor to a backing plate then glassed it to the hull over the hole. Then cut the thru hull to fit then installed the valve. I found a great photo explanaton on line but cant remember the site. Its hard to search from this phone.

[GordMay]

Generally, hand fit to finger-tight engagement, then wrench tighten 2 - 3 full turns (for sizes up to 1 inch) for Tapered (NPT) thread fittings.

You should have between 3.5 and 6 engaged threads in the final assembly.

Never dry-fit an NPT fitting “tight”, then back-off - it may not re-seal properly.

See the NPT Fitting Instructions ➥ http://www.surpluscenter.com/techhelp/NPT.pdf

And ➥ http://www.groco.net/SVC-MAN-07/Sec4/PDF/IBV-FBV-TB.pdf

[sharpey]

thanks for that

[Sailmonkey]

If you ever manage to bury all of the NPT threads you're using too big of a wrench!!!

[sharpey]

noted with thanks