Priming a Duplex Boiler Feed Pump

[Mfoxchicago]

Good morning Steamboaters:
I have a (if I am recalling this correctly) Garner-Deves Manual/Steam Actuated Duplex Boiler Feed Water Pump that is the primary feed pump for water from my tanks to fill the boiler prior to start up. Once the engine is up and running this pump can be configured to feed the hotwell or pump automatically to the boiler.

My boat & thus the pump have been on the trailer for the past 3 months (in W. Texas summer). Now that she is on the water and ready to get up first steam, I can not seem to get the pump to draw water from the tanks (which are full) and fill the boiler to proper start up levels.

Question - Is it possible or required that this pump needs priming with water to create the initial draw from the tanks. I only ask due to the fact the pump does sit slightly higher than the connection to the water tanks. I am of the opinion that the pipes have dried out during the summer and her refit time ashore. Could it need priming and if so, where might this "priming access" port/plug be located or look like.

As always - I am grateful for your knowledgeable and kind assistance.

Capt. Mack

[Mfoxchicago]

Confirmed the pump's make: It is a GARDNER - DENVER Duplex Pump. It has been recently rebuilt in the past two years. Was functioning normal when I rode on the boat in June.

[DetroiTug]

My steampump sets high. To get it going when dry, I installed a bleeder valve on the exhaust side piping. They cannot push air and pull water. Or just crack the line and let it run until you see water then retighten.

-Ron

[Mike Rometer]

Even the smallest air leak on the feed side will affect the draw of a pump, and certainly allow leak-back over a period. Check all connections and try to feed water into the bottom and past the first valve. Once it's wet it should draw again.

[Mfoxchicago]

Hey Guys, thanks for the speedy response.

Yesterday, we tried priming the pump via a standard garden hose fitting present on the manual side of the pump. We can move water through the pump to the first downstream outlet which is a fill for the clean water side of the hotwell. The next outlet is the float valve shut off inlet for the same hotwell chamber. From that point on, its a straight line vertical lift to the boiler inlet. However, none of these same outlets show flow when we are not priming via the garden hose.

We have confirmed that all the check valves & inline strainer baskets are functioning and clear of debris. Still unable to draw water manually from main feed tanks.

We did have a non functioning water tank level "bubbler" port we were in the process of sealing back up. From the posted replies, this significant air opening may be preventing us from getting the vacuum we need...???? The opening is now sealed. I will now fill both Port & Starboard saddle tanks to full, which should put maximum weight behind the waters natural gravity, help the vacuum. This will be my next tempt to get things moving.

I genuinely do not wish to be faced with cracking open the pump heads or be forced to remove the pump from the boat to solve this issue.

Does anyone else have a or experience with a Gardner-Denver DAB (AB-AB) Duplex Steam Pump?

As stated before, the pump had the springs replaced back in 2013, working well in June 2014 - now, not working. Could something internally have rusted up over the hot summer months when she was on the hard and having her bottom reworked?

I welcome your suggestions.

[DetroiTug]

I genuinely do not wish to be faced with cracking open the pump heads or be forced to remove the pump from the boat to solve this issue.

Does anyone else have a or experience with a Gardner-Denver DAB (AB-AB) Duplex Steam Pump?

As stated before, the pump had the springs replaced back in 2013, working well in June 2014 - now, not working. Could something internally have rusted up over the hot summer months when she was on the hard and having her bottom reworked?

I welcome your suggestions.

That's steam power. The water and steam carries sediments and minerals, causes rust and deterioration of certain metals. In short, unlike the fuel system on an IC engine, it's dirty and creates it's own problems.

Sometimes things just have to be disassembled to see what the problem is. It sounds as though you have a valve in the pump not seating or stuck open.

Without seeing a diagram of the piping on this pump, none of us can really help pinpoint the problem.

These things are known for sure about piston water pumps with metal seats positioned higher than the supply level moving water at ambient temperature:

1: There can be no vacuum leaks in the inlet piping from the reservoir/supply including the cylinder heads of the pump.

2: The valves must be free moving and able to seat near 100%.

3: Pumps like these that are typically equipped with metal seat valves will not pump against any sort of head pressure without water, i.e. trapped air, the pump must have water to move water through the valve chamber with head pressure. These pumps with good valves can pump air and provide some marginal lift of the water but there can be no head pressure on the outlet side of the pump. Why a bleeder valve that can be opened on the outlet side is beneficial in getting water up to the pump.

Nobody likes to mount these pumps out of sight down in the bilge below the supply level, but that is where they would operate best. Want it up where everyone can see it? It's going to be difficult to get along with occasionally. Once primed and operating with no leaks they are generally very reliable from that point on.

-Ron

[Lopez Mike]

I have had very good luck with plumbing in some outboard motor gas line hand squeeze bulbs before my feed water pumps. It helps with getting air and crud out of a pump AND if there is a plugged filter or any such obstruction on in suction side, the squeeze bulb collapses. Instant diagnosis.

Filters in all suction lines of course. Clear ones so you can eyeball what is going on.

[Mfoxchicago]

Thanks Ron & Mike, as always, the suggestions I get here are greatly valued and come from much experience. Thanks.

I believe I still have some air gap issues and will try again to isolate and correct those.

Since fully filling the Port/Starboard water tanks, I have sensed some improvement in the pump trying to pull "some" water. The nearest outlet is the fill line for the Hotwell. But, it is only able to produce a small "burp" of water, not near what I would expect or need.

I'll keep trying....thanks for the suggestions and the advice.

Much appreciated.

[Mfoxchicago]

Well guys, tonight is a good one to be Captain of TULE PRINCESS. My pump issues are resolved. After considering your kind and experienced advice, consulting the Gardner-Denver steam pump division in Quincy, IL and discussions with a few here that have experience with pumps, I determined that I had an "air in the feed line and piping" issue to fix.

With my Brother's steady stroke at the manual feed lever and my two handed, alternating, speedy contractions on the limp feed line - we were able to make water work itself up through the first check valve, into the main connection to the pump, past the second check valve down stream of the pump, up the riser and through another check valve right next to where the feed enters the boiler (which I did not know was a check valve), heard the "click" indicating water was passing through, felt the cold brass fitting from the cold feed water and saw the joyous rise of the almost non-existant water in the glass rise, rise and RISE to the point where I needed it to be for Sunday's First Firing!

It's a good day to be the Captain!

Thanks for all your support and assistance. This forum is SO valuable to me. If you would like to follow our progress, please LIKE us on Facebook as: Tule Princess

Let you know how first steam goes.