Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: ian kennedy on April 30, 2008, 09:48:45 pm

Title: boiler water feed pump?
Post by: ian kennedy on April 30, 2008, 09:48:45 pm

Hi, do any members have a tried and tested high pressure water feed pump design or know of a commercial one?

Title: Re: boiler water feed pump?
Post by: SteamboatPhil on May 01, 2008, 01:17:48 pm

Hi, what sort of pressure will you be trying to pump into. I have hand (and mechnical ) pumps on my steam boats which pump water into a boiler which is holding 150psi, is this the sort of thing you are looking.
Phil

Title: Re: boiler water feed pump?
Post by: ian kennedy on May 01, 2008, 10:58:35 pm

Hi Phil,

Thanks for the reply.

my boiler is set up with a working pressure of about 60-70psi.

I have tried a hand ram pump which does work very well but as i am playing around with a fully automated control system i really need a good strong pressured pump to be electronically driven and controlled.

What type of boat are you charging around with that needs 150 psi? that is some working pressure.

Regards
IAN

Title: Re: boiler water feed pump?
Post by: wideawake on May 02, 2008, 10:39:19 am

Quote from: ian kennedy on May 01, 2008, 10:58:35 pm

Hi Phil,

Thanks for the reply.

my boiler is set up with a working pressure of about 60-70psi.

I have tried a hand ram pump which does work very well but as i am playing around with a fully automated control system i really need a good strong pressured pump to be electronically driven and controlled.

What type of boat are you charging around with that needs 150 psi? that is some working pressure.

Leaving aside the means of measuring boiler water level, a normal hand pump with the lever replaced by a crank driven by a geared down electric motor would do the job.   There was an article in MB describing such a system a while ago including a sensor unit to fit in the boiler.

Also if you google for Malcolm Beak, you'll find an interesting article on the work he did on this subject on the paddleducks website.

HTH

Guy

Regards
IAN

Title: Re: boiler water feed pump?
Post by: ian kennedy on May 06, 2008, 12:15:48 am

Hi,
thanks for the advice but i think i've sorted the problem pump.
i can now replenish the boiler easily at a working pressure of 80 psi with no problems

thanks
Ian

Title: Re: boiler water feed pump?
Post by: BarryM on May 07, 2008, 08:24:12 pm

Ian,

Would you like to tell us your solution?

Barry M

Title: Re: boiler water feed pump?
Post by: ian kennedy on May 08, 2008, 08:15:42 pm

Well, as usual the answer was staring me in the face !!

Quite simply i was getting a hydraulic lock effect within the pump and clack valve.

all i did to over come the problem was to enlarge the water intake clack valve and replace stainless ball with nitrile rubber ones, these lift and seat better than S/S balls.

This allowed water to enter ram pump quicker= cylinder fills faster and empties faster with less resistance.

meaning i could use a higher speed geared motor to drive the pump as there is less torque required now.

All i need to do is perfect my automated water level/gas press/temp/boiler control system and it's sorted.

Cheers.