Re-seating check valve?

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Re-seating check valve?

Post by DianneB » Wed Jun 05, 2019 10:19 am

I have a right angle check valve on my 1/8 LE American that serves for feed water from my mechanical pumps. Last time out, it started leaking steam into the waterline.

I took it apart, cleaned the inside, flushed the lines, and seated the check ball with a light tap. Tested it again today and it is still leaking a LITTLE steam - not as much as before but still a few little steam bubbles.

I am wondering if I need to take it off and boil it in vinegar, and re-seat the ball.

I have a meet coming up on the weekend and I need this FIXED~ (It never did this before.)

Am I missing something?

John Hasler
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Re: Re-seating check valve?

Post by John Hasler » Wed Jun 05, 2019 1:00 pm

As I understand it you are supposed to throw away the original ball, use a new one for seating, throw that one away, and install a new one for use. This is for hydraulics, but I would think it would apply to steam as well.

I believe that the theory is that the leaking one may be worn and so should not be reused or used to create a seat, and the the one used to create the seat might have become damaged in the process and so should be thrown away.

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Re: Re-seating check valve?

Post by cbrew » Wed Jun 05, 2019 1:49 pm

i agree with John also, another idea that has been successful is using a hard viton ball instead of the Ss balls. it will conform to any issues in the seat, but the shelf life will be shorter. so plan on replacing the ball every spring. (normally buy 50 to 100 at a time anyways so this is not much of a problem)
just to note also, the seat much not have a sharp edge, the edge can be removed with a new stone
I hope this gives ya some food for thought
If it is not live steam. its not worth it.

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Re: Re-seating check valve?

Post by kenrinc » Wed Jun 05, 2019 6:16 pm

I have a set of "lapping" tools with different size balls on the ends that I made. Basically I take a ball end mill with a matching radius, cut a dish in the end of the rod, and then Loctite a chrome ball to that. I then use a none destructive lapping compound like "Time Savers" to lap the ball onto the valve seat.


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Re: Re-seating check valve?

Post by Builder01 » Wed Jun 05, 2019 8:13 pm

I use Viton. It seals 100% and is very tough. I use it especially on the check valve from the delivery pipe from my injector. Any leak here and the injector will get hot from steam directly from the boiler. (Hot injectors will usually fail). I replace this specific one each Spring. I gave up trying to get a SS ball to seal on this one!

I also use Viton on all the balls in my axle pump and hand pump. For the safety, valves, always use SS. No Viton here due to spring pressure.


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