Paddleducks

Other Marine Models => Live steam => Topic started by: Fred Graham on June 09, 2010, 01:03:46 AM

Title: Water Pumps and valves
Post by: Fred Graham on June 09, 2010, 01:03:46 AM

Hi Folks,

I have noticed that some of the commercial suppliers (Anton Monahan, and Hemmens) offer engines with a water pump run directly from the crank shaft.

The water pump has its valves set in a horizontal attitude.

In all the model mags I have read over the years water pumps were geared down by 4 or 5 to 1 and the valve boxes were always set inlet on the bottom and outlet directly above so the gravity assists the seating.

Given the amount of turbulence inside pump valve boxes, would the valves set horizontally seat quickly enough to avoid cavitation.

When I finished making my most recent pump I tried it using a varispeed drill set at about 100 rpm and held it so that the valves boxes were horizontal. Although it pumped, it was rather feeble. When I turned it so that the valves were vertical the output improved, markedly.

Is there something special about the pumps used on the suppliers pumps above or am I missing something. If anyone uses one of these pumps I would be most interested in your experience.

All the best, Fred Graham

Title: Re: Water Pumps and valves
Post by: old man on June 10, 2010, 07:20:47 AM

Hi Fred I have a Hennems steam engine with a horizontal water pump . Now I don't under stand all the techinal jagon but I can tell you that when I finish running the engine after about 3/4 to 1 hour duration continual, I still find the boiler at least half if not more full sugesting the pump certainly can keep up with consumption. Like I said Ihave no techinal Knowledge but I am very satisfied with way everthing works Hope this is of some use.
                                                                   Old Man


                               

Title: Re: Water Pumps and valves
Post by: R.G.Y. on June 11, 2010, 04:00:57 AM

Old man, can you get permition to attend fathers day meet at Crealy. If so I will see you there. Geoff I shall have my Paddler ther and my trawler.

Title: Re: Water Pumps and valves
Post by: old man on June 11, 2010, 04:59:43 PM

Hi Geoff, I shall be there on fathers the one day of the year when I can do what I like FREEDOM  YIPEE

                         Old Man

Title: Re: Water Pumps and valves
Post by: Fred Graham on June 13, 2010, 05:30:24 AM

Hi, OLD MAN,

Yep, that's of use to me as I'm trying to establish how horizontally arranged valves perform as it is more usual to set them up in the vertical attitude, (ie the balls go up and down in the valve chambers.)
It would appear that your balls perform very well If you'll pardon me for saying so!

All the best, Fred Graham

Title: Re: Water Pumps and valves
Post by: derekwarner_decoy on June 13, 2010, 10:22:32 AM

Oh Dear Lord of moderation.....please forgive them  as they know not what they say  :oops  "It would appear that your balls perform very well"   :c017 ........whilst we more mature [in years] members will just sit back  :gathering & laugh.....Derek

Title: Re: Water Pumps and valves
Post by: old man on June 14, 2010, 05:00:01 PM

To one and all,   never give up hope,  I am some what mature having retired and got my bus pass but my steam engine still works ta very much..............Old Man