Nathan double top check boiler feed valve

[phil davis]

I'm after any photos of the Nathan double check valve as attached, I need to 3d model it however the drawing is difficult to get all the casting shapes. A photo or two of it on any locomotive would be much appreciated. Searching the web has been fruitless.

[Greg_Lewis]

You might check with the library at the California State Railroad Museum. They have a lot of stuff. If you contact them they might do a search for you — don't just check the website. https://www.californiarailroad.museum/visit/library

[Bill Shields]

I have something on a 2.5" gauge loco that performs the function, but it built from bar stock.

Any help?

[BAdams]

You might need and Optivisor (I know I would) -
Cal Scale has an HO scale detail casting #190-251 Check Valves Nathan Double Top Feed (there's photos of them on eBay) that might help you out.
Precision Scale has one as well in HO #2702 https://www.precisionscaleco.com/wp-con ... ne-WOP.pdf

The Grand Trunk 6300 series locomotives have top mounted check valves - are they are Nathans, I have no idea, but they look similar.


Brook

[RThomp]

Didn't Brian Keim make a few of these in 1.5 scale?

[jkimberln]

I think Anthony Duarte asked if there was any interest in these. It didn't appear that there was much. They were popular on European Locos, especially Beyer-Peacock Garratts where the Sellers version was used.

Some time back, I made one using one bronze casting.

[jeffsmith]

I would like to see someone produce one of the double injector check feed valves in 1.5". It would save a lot of work scratch building one.

[Greg_Lewis]

I note with curiosity that the side for the feedwater heater is different than the side for the injector.

[RThomp]

I'd reach out to Keim Steam pump. I'm 95% sure Brian built a few. I remember seeing a pic of one of the Erie 4-6-2s he built and it had this style check.
this was a fairly common design feature on many locomotives.

[Asteamhead]

Phil,
For my class A 1239 I built one in scale 1 : 10 from bronze. Parts were siver soldered. Spindles and valves are made from stainless steel. It's built by means of the drawings you posted (source: Locomotive Cyclopedia 1947) and those from the N&W historical society.
Fully functional it's working fine on my locomotive both with injector and feedwater pump.
The different valves between piston hot water pump (left side) and injector (right side) are due to the more critical one without spring pre-load for use by the injector.
You' ll find more details in my thread 'My class A 1239 with ...' on this forum. Perhaps this may help? More photos and scetches are available.

Best regards Asteamhead

[Fender]

I think the idea with the top-feed check valves was to feed the water into a perforated trough above the water line, so the incoming water would be heated by steam, rather than mixing cold water into the hot water in the boiler. This tended to drive out the dissolved oxygen from the incoming water, and reduce thermal shock to the boiler.

[Dick_Morris]

Steamtown has a large collection of Nathan drawings. The one you posted is probably from the assembly drawing that they would have. The "official" drawing would be identified by the Nathan number and have a parts breakdown with the individual part numbers, which they should also have. In a data base I got from them a few years ago there are several "double boiler check" valves listed, with some specifying that they are for the top of the boiler. The key is finding the Nathan part number for what you are looking for. here is one I picked at random -

4502 - Type FWP double boiler check valve location on top of boiler for use : with injector and feed water pump 1943 January 7 linen ; architectural drawing ; half size

I've got a number of drawings that came from from Steamtown that we have used of the ARR 557 restoration. They have always been very responsive to requests.