DetroiTug wrote:I was a little confused with the up/down stream
I knew what was meant.
Den, The plan has always been to keep the boiler and engine install as simple as possible. If I could get by with a boiler, an engine, and a "hank" of copper in between, that would be great.
Going to add the isolation valve in between the boiler and the feedwater check today. Mount the 12volt pump which shouldn't take long. It is supposed to be 50 degrees Monday, that may be test day.
-Ron
Some comments:
1. While keeping it simple is laudable, the savings in eliminating many valves, fittings and piping is not enough to pay for a funeral at today's prices.
2. You have no shutoff valve between your through hull fitting and the hose supplying the pump. etc. If you
won't ever have your boat in the water in freezing weather - and I understand that it
does freeze in Detroit - then you don't need a proper seacock (an integral valve and thru hull assembly). But there are lots of boats that sink every year because of this lack - ice can burst extra heavy pipe, flexible "rubber" hose bursts at very low pressures.
3. I personally like to use 90deg. check valves and globe valves where ever check and globe valves are needed. Frequently this occurs on vertical lines that will make a right angle turn before going into a device. Less restriction to flow, more compact layout, greater ease in operation.
4. When installing check valves at a pump they should be
as close as possible to the pump - like screwed right into the pump body. This prevents loss of flow when the piston moves back and forth. Most quality pumps have "back flow preventer valves" as an integral part of the pump unit. And if the line from the pump to the boiler is over four feet, I strongly recommend another check valve be mounted just before the feedwater stop valve at the boiler. A small "bleed valve" on a "T" should be located just before the final check valve to bleed any entrapped air in the line, otherwise you can have "air lock". All of this, along with a pressure gauge (tells you if the pump is working) and a water pressure relief valve should occur just
before the check valve at the boiler stop valve. And if you encounter "water hammer" - you shouldn't if your pump discharge lines are kept reasonably short, pump suction line is one size larger than discharge line and there are no sharp bends in the discharge line - this is also a good spot to insert an "air cushion" or "surge chamber".
Important Note
Most check valves have
TOO MUCH LIFT for an engine driven feedwater pump of any kind. And the faster the engine turns, the more important this excess movement is. Many check valves in the 3/8"+ size have a lift in excess of 1/8" - this wastes pumping action as the valve takes so long to close (relatively speaking) that some water will "backflow" through the check valve before it closes. Limiting the check valve travel to 3/32" or less will greatly improve pumping capacity.
. The way I'll use it is just open the top trycock and keep filling until water comes out. Tentatively, of course. I don't know what the actual procedure will be, whatever works best. 
