Thread sealant for seacock ball valve?

[slug]

Chrome plated stainless ball valves are being replaced with ceramic valves

Chrome plating is s very toxic business ... heavily regulated by environmental authorities ... hence expensive To produce unless you chrome plate in the third world, China ...

Ask your supplier about ceramic valves that fit your specifications

https://www.verspec.com/ceramic-valves-and-fittings/ceramic-ball-valve-with-forged-steel-material

[Dougtiff]

Tape and goop both work well, however to use tape, it should be wraped tight, clock wise direction, or it will slip, and not do it' job, i use goop, when it's not possible to wrap tape properly,about different thread's, NPT and BSP is TAPERED, and needs tape or goop, tapered as stated earlier does not need anything on the thread is WRONG !, moving on, Marine thru hull's and Marine valve's are STRAIGHT thread's, also need tape or goop. I.E., when i was commercial Diving [Oil industry], i got talked into running the shop in singapore for Ocean Engineering, was responsible for building new equipment, think Saturation system's, I.E., diving bell's, decompression chamber's, ect., mobilizing and de- molizing system's, think ,life support system's, i have used more thread tape than i wish to think about, case in point, except for "O" ring sealing, ALL thread's must have a sealant on the thread's !

[mitiempo]

Originally Posted by Dougtiff

.... moving on, Marine thru hull's and Marine valve's are STRAIGHT thread's, also need tape or goop.

Thru hulls are straight (nps) threads in North America but ball valves from Groco, Conbraco, etc are tapered threads (npt)

That is the main problem with builders and others just threading a valve on a thru hull - it is a mis-match.

https://marinehowto.com/seacock-thru-hull-primer/

[Ken Fry]

Originally Posted by er9

I dont think he would use the Sika 291 because it seems that would make it difficult to remove if necessary.

Thanks

Not to recommend a particular brand, but BoatLife works well as both a bedding compound as as a pipe sealant. In a pinch, it even can stand in for a thread locker: the fitting might loosen before it would with Loctite, but at least you are unlikely to lose the nut.

Pipe fittings (NPT) which have tapered threads are always correctly assembled with pipe dope (or teflon tape if the fluid contained is not compressed air or natural gas) (because the tape particles can get under valve and regulator seats, causing problems). To say, as a rule, that NPT fittings do not require dope is just plain wrong. NPT fitting can often be made to seal if made very tight, but some cannot, because there are always small flaws in the threading that cannot always be crushed enough to seal.

Straight thread fittings will never reliably seal, no matter how tight -- they are not intended to do so. They are intended to apply a high force in line with the shaft of the screw, and that high force can be used to force two smooth flat flanges together, to compress a compression fitting, etc. The sealing surface in a compression fitting is beautifully machined and needs no dope of any sort. For other surfaces, and uses, one must follow the manufacturer's advice.

I've seen pipe fittings by the thousands in industry, developed training on the subject, and the pros always use some form of sealant on tapered pipe fittings.

https://www.thisoldhouse.com/plumbin...ng-connections

https://www.kitplanes.com/best-practices-sealants/

[MalteseFalcon]

Originally Posted by sanibel sailor

Straight or taper threads? Taper does not require sealant. Teflon tape reduces force needed to seat but does not “seal”

This is very wrong information, Teflon tape is a lubricant but it also sealer that is its main purpose.

[deblen]

Originally Posted by mvweebles

I'm a bit confused, but probably just semantics. To me, thru-hull is a somewhat generic term. A common configuration is a mushroom thru-hull with straight thread stem. On the inside is the valve - I typically use the term "thru hull" for the entire assembly.

The Groco adapter plate (which I assume is what is being discussed) appears to be an un-valved method to transition from straight thread to NPT to allow installation of a ball valve. The broad triangle base is clearly stronger than mounting a ball valve directly to the stem of the mushroom fitting, but my confusion comes in mounting the triangular base plate requires same work as mounting a proper seacock and cannot be done properly with boat in the water.

I must be missing something. I'm redoing thru hulls as we speak so interested in feedback. Though I am a fan of well-backed seacocks.

https://www.groco.net/products/fittings/thru-hull-fittings/ibvf-flange-


adaptor

This site may help. / Len
https://marinehowto.com/seacock-thru-hull-primer/


https://www.cruisersforum.com/forums...=1#post2890243

[sailah]

As a steam guy (as in boilers) I see Megaloc as most common pipe dope, some even dope then tape (Blue Monster being favorite).

For threaded fittings requiring sealant my absolute favorite is Loctite 567. I use it on everything I'm in charge out outside iron pipe. Has Teflon in it so no tape required for lube.

https://www.mcmaster.com/45855K27/

[er9]

Thanks all for all the great info.