I like the idea of soft seats...but shudder at the thought of ring failing during operation. It would just be my luck to have a large scale failure.
Metal on metal may require periodic maintenance...but the failure mode.. a slow leak...Is preferable to a major failure.
Now.. a soft seat valve that will hard seat if the o-ring disappears is the best of both worlds...or if you have another check upstream.. whole different kettle of fish.
Boiler check valves
- Bill Shields
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- Joined: Fri Dec 21, 2007 4:57 am
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Re: Boiler check valves
Too many things going on to bother listing them.
Re: Boiler check valves
I agree, but In fairness there are tons of people using the PMR or mercer valves, haven't heard a single bad word about either.
Re: Boiler check valves
Thanks for sharing your drawing Jack. The 2.5 inch scale one is a good model of the style used by the Denver and Rio Grande. I have attached a photo of the prototype.
I have started to make some very similar, but not having Jack's fabrication skills decided they might not be reliable enough for the injector feeds on my C21 and have bought PM Research valves along with angle globe valves to tie into the boiler. I will try my home made valves on the lines from the back up pump.
I have started to make some very similar, but not having Jack's fabrication skills decided they might not be reliable enough for the injector feeds on my C21 and have bought PM Research valves along with angle globe valves to tie into the boiler. I will try my home made valves on the lines from the back up pump.
Re: Boiler check valves
These are what I built:
The check valve uses a 'T' with an O-ring.
They don't have enough history to be labeled reliable, but I have had no problems for about 5 years.
If anyone is interested, I can post the drawings.
A couple of caveats:
I'm not a mechanical engineer, so my drawings tend to be line-on-line.
The square knob needs to be removable to assemble or repair, but it's kind of fragile.
It was originally pinned, but I sheared the pin trying to open the valve (when it cools after a run, it tightens up).
I tried making a square on the shaft and a square hole in the knob, but I still have to be careful.
I leaks a bit with no pressure in the boiler. There is a spring installed, but it may be too weak. Too strong and the injector won't overcome it.
Karl
The check valve uses a 'T' with an O-ring.
They don't have enough history to be labeled reliable, but I have had no problems for about 5 years.
If anyone is interested, I can post the drawings.
A couple of caveats:
I'm not a mechanical engineer, so my drawings tend to be line-on-line.
The square knob needs to be removable to assemble or repair, but it's kind of fragile.
It was originally pinned, but I sheared the pin trying to open the valve (when it cools after a run, it tightens up).
I tried making a square on the shaft and a square hole in the knob, but I still have to be careful.
I leaks a bit with no pressure in the boiler. There is a spring installed, but it may be too weak. Too strong and the injector won't overcome it.
Karl
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- Posts: 132
- Joined: Sat Mar 11, 2006 9:44 am
- Location: North of Reading PA
Re: Boiler check valves
Hi Folks;
Globe style checks, Nathan and Hancock checks are available from Superscale. I will have plenty of stock of them in a few weeks as castings just arrived. Please email to DSBortz@Comcast.net and let me know what your looking for, and I will be happy to provide.
Thanks for your support.
Dave Bortz
Globe style checks, Nathan and Hancock checks are available from Superscale. I will have plenty of stock of them in a few weeks as castings just arrived. Please email to DSBortz@Comcast.net and let me know what your looking for, and I will be happy to provide.
Thanks for your support.
Dave Bortz