A hydraulic hand pump

[Firebird]

Hi

Heres a few photos and some plans of a pump I built a while back to test my small boiler. I will use it again to test the boiler on my portable engine.









All the parts layed out on an enlarged plan



Any questions please ask, I have more photos and details.

Cheers

Rich

[arnoldb]

Thanks for showing your pump and plans Rich 

Having built one myself to your plans (not as good looking though!) and after pressure testing a couple of boilers with it, I can really recommend it 

Kind regards, Arnold

[smfr]

I read that when building the Stuart hydraulic pump, you have to be really accurate. Is it just that the piston needs to be a very tight fit to the bore, otherwise it leaks?

Simon

[chuck foster]

thanks for the plans rich  and as usual that is a mighty fine looking piece you have made.

chuck

[Bearcar1]

I remember when you built that Rich,......... NICE! 

BC1
Jim

[Firebird]

Hi

Thanks gents.

Simon, the piston needs to be a nice sliding fit in the bore. The piston here is stainless steel and is bang on .25 so all I had to do was carefully ream the bore. The trick is getting the O ring groove right. The O ring in this case .25 OD with .125 ID making the walls of the O ring (if thats the right term) .0625.  When turning the groove in the piston it must be slightly larger than .125 so that when the O ring is fitted it is slightly larger than .25 and therefor makes a good seal when squashed into the bore. Although the plans show the O ring groove to be .0625 wide it does in fact need to be slightly wider so that when the O ring is squashed down, making it oval in section, it has an equal amount of room to move sideways. I think I'm right in saying that O rings won't compress but just change shape. A quick search on google and you will find plenty of info re O ring groove sizes.

Cheers

Rich