PEEK for gas shutoff tip

[Omarttentmaker]

Wondering about the type of PEEK that everyone uses in different spots to seal. Looked up a local supplier and they have different grades. There's standard, bearing grade and glass-filled. Is there an advantage to using one over the other? I would suppose that the bearing grade style might be what to use for the application described in the title, as there would be some friction involved when tightening down the shutoff rod, but I'd still like some input from anyone who's used the stuff for this or any other sealing application.....Thanks in advance for any info.....Omar

[larry]

I've used the grey peek from McMaster Carr. I don't recall the grade.

[T. Cotten]

I used Ensinger "natural" PEEK, Omar!

PEEKpetcut.jpg


Until I realized it was stupid and silly to destroy the original.

The final cut was all that's needed to clean up an OEM tip.

....Cotten
PS: I've got plenty of PEEK if anybody needs some, at half the price of MSC, by the gram.

PEEKCORE.jpg

[Omarttentmaker]

I used Ensinger "natural" PEEK, Omar!

PEEKpetcut.jpg


Until I realized it was stupid and silly to destroy the original.

The final cut was all that's needed to clean up an OEM tip.

....Cotten
PS: I've got plenty of PEEK if anybody needs some, at half the price of MSC, by the gram.

PEEKCORE.jpg

thanks to all....Curious as to the angle on the tip. Using what I have to measure, it appears to be 45 degrees....Yes or no? And is the seat angle the same, or is it cut to produce a tangential seat around the mouth of the hole in the screw-in fitting?

[T. Cotten]

45° is what I use, Omar!

The seat is difficult to cut, as it is deep below a pressed-in guide collar for the shaft. Since it is brass, however, it can be easily burnished by holding a shaft with a dressed original tip in the chuck, and forcing the seat upon it a few times with a wrench, before giving it the suck test.

....Cotten

[Omarttentmaker]

45° is what I use, Omar!

The seat is difficult to cut, as it is deep below a pressed-in guide collar for the shaft. Since it is brass, however, it can be easily burnished by holding a shaft with a dressed original tip in the chuck, and forcing the seat upon it a few times with a wrench, before giving it the suck test.

....Cotten

You bet....just got the fitting out of the tank, and I can see the seat around the mouth of the hole. So burnish is better than lapping? I'm guessing you're thinking that you'd never be able to remove all the compound from the seat, doing more harm than good.

[T. Cotten]

Lapping brass is a bad idea, Omar!

Many abrasives embed into brass (except maybe flowers of sulfur or cigar ashes, etc.), so reforming it by 'burnishing' is safer.

Note also the soldered and pressed thread collar would have to be removed and replaced afterward, as you cannot spin the shaft to lap.

PTCK1.jpg
As you can see, I have already made every mistake possible.

....Cotten

[Carl Olsen]

If you want one that works just order one of our complete PEEK tipped gas valves that we have been making for around 20 years. It comes with the 2 knurled nuts, one Cad and one Chrome, spring, washer, rubber seal for the top of the tank and bottom Cad plated seat with a stainless steel seat and rod pilot pressed in. Everything is interchangeable.with OEM and comes with a money back guarantee, however I have never had to refund anyone's money and they have just led to more sales. No pressure turning it for a full and permanent seal every time.
Carl