A question about Coffin feedwater heaters...

Model Railroader Prototype information for the modeler
1

I’m attempting to build a model of one of the DW&P’s N-2-a Consolidations, and am a bit confused by the piping for the exposed Coffin feedwater heater. I have four fairly good prototype photos, and there’s a pipe, from what should be the cold water input fitting on the fireman’s side of the heater, running to the top feed check valve. [:O] The hot water output fitting, on the engineer’s side of the loco, has its pipe disappearing behind the access steps to the walkway, and not making a re-appearance. The injector piping, also on the engineer’s side, runs directly to the top feed check valve, as would be expected. Since the cold water feed pipe, from the pump on the fireman’s side of the loco, seems to disappear under the boiler, it seems logical to me that the cold water input and hot water output fittings are reversed on these locos. Were Coffin heaters set up for bi-directional flow of the water? In other words, could the cold water be piped in on either the right or left side of the heater, with the hot water coming out of the fitting on the opposite side?

All of the other feedwater heater piping seems to start and end in the proper places.

Wayne

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Wayne I’m not certain, but I THINK I have some literature on Coffin FWHs that might help answer your question. But it’s sort of buried at the moment. I’ll have a scratch around and see what I can find.

Cheers,

Mark.

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Thanks, Mark. What little bit of info I can locate on Coffin fwhs usually shows two check valves on the engineer’s side of the loco, with the hot water output from the heater also on that side. It seems odd that, with a dual-feed top-mounted check valve, they’d re-route the cold water piping just to get the hot water feed pipe on the “normal” (as when an Elesco or Worthington was used) side of the boiler.

Wayne