The Home Machinist!

Lots of people used to get and modify those Kingston air pressure relief valves and use them as safety valves. I've used a J09SS before, with stainless spring and ball, but now I can't find them for sale anywhere. I fear that they have been discontinued. So what are others using/modifying?

There is another Kingston valve that is similar, but it is much tallet band bigger around in the body too.

Seems like there are lots of kIngston low pressure valves on line. I found one eBay site with a brass Kingston 1/4” NPT pipe for $9.99.

Says they are adjustable from 50 psi up to 375.

Glenn

Pontiac Guy...purchased my Kingston relief valves thru surpluscenter.com. These folks are located in NE. Checked their website, but no longer see the style relief valve I got. Perhaps they ran out of stock.

Would suggest check places like McMaster-Carr, MSC, Zoro, Grainger or similar. Glenn is spot on with price...should be able to acquire these relief valves in the $10 range. However, they are side discharge valves. The adjustment nut on top will need to be drilled for the new relief holes...and the side discharge holes closed or covered over. Hope that helps. Carl B.

Thanks, I know how to modify them, having done this before. I just haven't bought any new valves In about 10 years and now can't find the exact same type and size that I used before.

There is another way to modify them too... make a sleeve (body) to be pressed around the outside of the valve and which is hollow on the inside and has the discharge holes in the top of it. Looks a lot more prototype, no mods needed to the actual valve parts themselves, but it is a lot more work.

BTW, Surplus Center is where I got the last ones that I bought, and that was one of the first places I looked. It has been 10 years since I bought any, so if they have discontinued that valve, what part number are you using now?

Go to the source.
http://kingstonvalves.com/product/model-125ss-2/
Fred V

Thanks guys. For some reason I couldn't find them. Apparently the part number is now different or something, but that's what I was looking for.
Found a place on Amazon selling them for $17.08 each. Probably going to order 5 or 6 more of them.

www.amazon.com/Kingston-125SS-Brass-Saf ... B006U4I5N4

Pontiacguy1 wrote: ↑Sat Jan 27, 2018 7:56 am Thanks, I know how to modify them, having done this before. I just haven't bought any new valves In about 10 years and now can't find the exact same type and size that I used before.

There is another way to modify them too... make a sleeve (body) to be pressed around the outside of the valve and which is hollow on the inside and has the discharge holes in the top of it. Looks a lot more prototype, no mods needed to the actual valve parts themselves, but it is a lot more work.

BTW, Surplus Center is where I got the last ones that I bought, and that was one of the first places I looked. It has been 10 years since I bought any, so if they have discontinued that valve, what part number are you using now?

This is what I did, plus this modification: http://www.chaski.org/homemachinist/vie ... =8&t=98707

I got mine from Surplus Center as well back in 2011. Good to know they're still available, albeit under a different part #.

I remember reading your thread. Thanks for reminding me.

How well do these modified air safety valves operate with steam?
How positively do they POP open and close?
How adjustable are they for both opening and closing pressures?
Inquiring minds have wondered about these for a while.
Thanks.
~RN

They work fine with steam at our pressures, being built from only brass and using a stainless steel ball and spring. Be sure to only get valves with the SS designation for stainless steel ball and spring. They state they are rated to 400 degrees use. Some of them tend to vibrate when they are popping, which is what John was trying to address in the above link. You can adjust them anywhere from lower than 50 PSI to over 150 PSI, and can do it easily. Best to adjust them under steam as the temperature will change the set pressure a little bit.

They open positively and close sharply. You are actually "pre-warned" of the impending lift as there is a small "crack" about 2 seconds before they lift (you can see and hear it in the video). They are as loud as all hell but they work really well. My 2nd one never lifts when running but I test it in the bay before every run and it pops when I hold down my main one. They are adjustable for poping pressure but not for reseating. I called Kingston and asked for the reseating pressure and I can't remember what it was. I think it was like 8 to 10lbs. The various modifications you see are to try to eliminate the "farting" that tends to happen on the stock valves. The mod does seem to reduce this quite a bit.

Here is a link to a video of them working:

https://youtu.be/0xEKDtu1SXs?t=188

Ken-

I find that they don't reseat well but fizz until I tap it with my slicebar.