Boiler feed pump ?

For technical tips, questions etc. on all subjects except Engines and Boilers.
ianrichards
Full Steam Ahead
Full Steam Ahead
Posts: 147
Joined: Wed Jan 11, 2017 12:30 pm
Boat Name: Isambard
Location: Calstock, Cornwall, UK

Re: Boiler feed pump ?

Post by ianrichards » Tue Mar 19, 2019 1:31 pm

Very, very nice.
Food for thought.
Thanks
Ian
User avatar
dampfspieler
Warming the Engine
Warming the Engine
Posts: 79
Joined: Wed Nov 18, 2009 6:59 am
Boat Name: No Boat Yet
Location: Neubrandenburg, Germany
Contact:

Re: Boiler feed pump ?

Post by dampfspieler » Tue Mar 19, 2019 1:45 pm

Here a crank driven feed pump (Steam launch "Bell Bird" 1876).

Compound_BellBird001_Kl.jpeg
Compound_BellBird001_Kl.jpeg (77.04 KiB) Viewed 711 times

The crank is at the outside excenter.

Dietrich
ianrichards
Full Steam Ahead
Full Steam Ahead
Posts: 147
Joined: Wed Jan 11, 2017 12:30 pm
Boat Name: Isambard
Location: Calstock, Cornwall, UK

Re: Boiler feed pump ?

Post by ianrichards » Tue Mar 19, 2019 1:47 pm

Thanks
Ian
User avatar
Lopez Mike
Full Steam Ahead
Full Steam Ahead
Posts: 1683
Joined: Wed Dec 07, 2011 6:41 am
Boat Name: S.L. Folly
Location: Lopez Island, Washington State, USA

Re: Boiler feed pump ?

Post by Lopez Mike » Wed Mar 20, 2019 1:50 am

So you have farms in the U.K., right? And those farmers spray their crops. And almost certainly they use some version of what we use here in the states which is an eccentrically driven piston pump. These are also used extensively in self service car washes which I suppose are common over there as well.

I have a single cylinder 3 x 4 engine and I have a Hypro brand pump driven right off of the end of the crankshaft. It never gives me a moment's trouble and has about a 20% or so excess capacity which is bypassed into the hot well through a float valve.

I love watching crosshead driven piston pumps run but only on other people's engines. Sort of like my reaction to square meters of brass.

If you go for a new pump it can get pricy (300 USD+) but there are used ones for much less and they are infinitely rebuildable.
Galileo - Great mind.
Newton - Genius mind.
Einstein - Extraordinary mind
Me - Never mind.
ianrichards
Full Steam Ahead
Full Steam Ahead
Posts: 147
Joined: Wed Jan 11, 2017 12:30 pm
Boat Name: Isambard
Location: Calstock, Cornwall, UK

Re: Boiler feed pump ?

Post by ianrichards » Wed Mar 20, 2019 6:51 am

Now that’s certaworth investigating.
Thanks Mike
User avatar
fredrosse
Full Steam Ahead
Full Steam Ahead
Posts: 1606
Joined: Fri Nov 20, 2009 5:34 am
Boat Name: Margaret S.
Location: Phila PA USA

Re: Boiler feed pump ?

Post by fredrosse » Sun Mar 24, 2019 4:21 am

I have made very reliable feed pumps from common brass pipe fittings with two common swing type check valves. The interior bore of brass pipe is so smooth that no further finishing is needed, and a piston machined from brass bar stock has worked well, with a couple thousanths of an inch clearence in the main pumping cylinder brass pipe. I use two common "O-rings" for piston to bore seal, about 1/8 x 1/8 grooves cut into the piston (about one inch diameter piston) for o-ring fit. Several years service so far, without any O-ring failures nor leakage.

The general "rule of thumb" for O-rings in dynamic pumping service is to provide a piston groove that results in the O-ring cross section standing proud enough to assure contact all around the cylinder bore, with 85% of the ring groove being rubber filled. More crowded grooves will rapidly wear the O-ring. Be sure to remove any sharp corners on the grooves, and be sure to provide a tapered entrance at the beginning of the cylinder to allow insertion of the piston without cutting the O-rings during assembly.

This type pump works well at low speed, either fitted with a hand lever, or driven from a crank at up to about 100 RPM. I would recommend either toothed belt or bicycle chain drive to a reduced speed lay shaft for engines running at much over 100 RPM.
ianrichards
Full Steam Ahead
Full Steam Ahead
Posts: 147
Joined: Wed Jan 11, 2017 12:30 pm
Boat Name: Isambard
Location: Calstock, Cornwall, UK

Re: Boiler feed pump ?

Post by ianrichards » Sun Mar 24, 2019 6:29 am

Thanks
Ian
User avatar
Ramón
Warming the Engine
Warming the Engine
Posts: 79
Joined: Mon Oct 26, 2015 2:32 pm
Boat Name: No Boat Yet
Location: Rostock, Germany, Baltic Sea

Re: Boiler feed pump ?

Post by Ramón » Thu Jul 11, 2019 2:31 pm

Oh man, Dampfspieler! This is really beautiful. You really can spiel with Dampf.

I follow the same path as fred. With those fittings you can get all over the globe, you can build one with almost no investment, cheap as they are. And so many different sizes make it easy like Lego :idea:
Post Reply