Getting valves to seal.

Help please! I've made all my steam fittings and they all leak. Clack valves leak despite giving the ball a sharp tap with a light hammer. The safety valves are salter spring type with cone shaped valves and they leak and the whistle valve leaks. What is best way to get a leak free valve please?

Did you drill or ream the through holes?

Did you drill, bore or "D" bit the seating?

I drilled the hole undersize, then D bit the seating , followed by reaming the hole .

I always make the seating separately from the body, and screw it into position. The hole I drill and ream, then machine the top surface to a shallow cone (volcano shaped) which seems to help keep it free from dirt. After screwing the seat into the body, which is threaded right through, I fit the ball and press it lightly into the seat with a threaded plug. This seems to make a better seating than tapping with a hammer. It is better to use a temporary hardened steel ball to press into the seat, rather than the actual ball that you intend to use, as pressing or tapping the ball may damage it. I read of this method in M.E. Many years ago, and it works for me.

Maurice

Thanks Maurice. If I have to remake them It sounds like a good method. I presume the ones you buy don't leak does anyone know how they achieve that?

I wouldn't be so sure about commercial ones! I had two commercial 3/8" clack valves brand new, unused, in old Reeves packaging so I had to assume they were from that source. They came to me with a pile of bits with my 4" Winson Ruston and Proctor. The original Winson ones leaked like a sieve so I tested the "Reeves" ones cold on compressed air at 90 psi in a bucket of water - looked like it was boiling! Took them apart thinking they were possibly dirty but they were as clean as the day they were made, never bothered trying them hot. Ended up making my own.

Paul.

I have had a lot of frustration making clacks. One tip I read in a Kozo book recently is to have the seat at 15 degrees and tap the ball only hard enough to make a small ring. He reasons that the smaller the seat ring the more pressure per unit area to seal it. I am yet to try it. Viton balls work well using one size smaller hole with a slight chamfer on it so as not to cut the ball. Steam Fittings valves work well they use a little plunger and o-ring instead of a ball however they leak when steaming up until you have raised some pressure to seal them as the plungers are light.

Thanks for the feedback, I might try the nitrile balls or viton balls. Do you machine the chamfer on the seat during making them or what please? I read the article on making them with O rings in ME and might try that. It sounds like not all commercial clack valves are equal. Perhaps we should have tests on these in ME since they seem to cause a lot of people trouble.

My guess is different valves from the same supplier will be behave differently depending on how good the cutting tool was at the time etc. So a review might get a particularly good or bad example.

Given so many people have problems with them I'm guessing you just need to keep making them until you find a technique that works for you and your equipment.

I'm tempted to try the tophat/o-ring style. They sound easier to make.

Edited By David Taylor on 10/03/2018 22:26:05

Edited By David Taylor on 10/03/2018 22:26:29

You get a lot of good advice on this forum this is how my hydro with very fast pump stroke valves are designed every thing is stainless steel. as you can see the ball seat is not flat.

I have very few times when the balls do not seat when it becomes awkward normally a bit of dirt is the problem.

Thanks David and Windy. What is a top hat style valve please? Is it the same as a shuttle with O ring. Can you do a drawing please? Windy I don't understand how you make that shape valve seat without it being a separate piece?

The other place I have leak problems is on the Salter spring balance safety valves which have cone shaped metal valves. Is it possible to use O ring seats or shuttles on safety valves or would there be a danger of these sticking?

Hi John,

On my valve seats the bottom feed is no problem but the others I use either a drill or a slot milll of suitable diameter and hand grind to an internal angle.

I use a very slow speed to minimize chatter then solder a steel ball of the size am going to use in the valve to a piece of bar and rotate that ball on the seat to burnish the seat.

Think an article by Bob Kirtley 1990? ME explains how he makes his pump valves not sure if he makes his seats conical.

Will have a look and post the article when found.

Here is Bobs article a bit dog eared.

Thanks for posting that. It's difficult to see but the seats look conical - the wrong way!