stirrup pump

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roughboy
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Sat Feb 07, 2009 10:47 am

What is the best check valve to use on a homemade stirrup pump? I've read that there are a few out there. there are ball check valves, diaphragm check valves, swing check valves, ect.





What is the best size (34'') (1'')(ect.) of check valve that makes a pump, pump faster?
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john bunsenburner
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Sat Feb 07, 2009 10:52 am

I just got my self some 10mm check valves, i guess the bigger the better is the way about this.
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roughboy
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Sat Feb 07, 2009 11:20 am

Which do i use a 2-way check valve or should i use 2, one way check valves?
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john bunsenburner
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Sat Feb 07, 2009 11:41 am

2 one ways are the easyer way IMHO.
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roughboy
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Sat Feb 07, 2009 12:01 pm

what air hose should i use? should i use the regular gas station air hose? will it hold 300 to 400psi?

what is the name of the fitting to put on the hose that will supply air into my gun?
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john bunsenburner
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Sat Feb 07, 2009 12:18 pm

Use the hoses used for welding with O2 cylinders they can hold alot. and i cant help you with the fitting sorry.
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Ragnarok
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Sat Feb 07, 2009 12:29 pm

If you don't mind, I'll respond to your PM here
roughboy wrote:What kind of check valve did you use?
I used one standard 1-way check valve.
what is the check valve size?
1/8" BSP - I kept all the piping at the bottom of the pump as small bore as possible to reduce the dead space at the bottom of the pump stroke - this is what allows the pump to manage higher pressures, and also improves efficiency.
what is the name of the blue hose and size?
It's a 3.6m long Polyurethane recoil hose, 6/4mm diameter.

However, the exact sizes I mention here shouldn't be of too much concern to you, just keep the bores reasonably low for the airhose and check valves - it saves on the air that doesn't make it into your chamber.

~~~~~
what is the name of the fitting to put on the hose that will supply air into my gun?
I used a Series 21 Quick Disconnect fitting. Much less fuss than a Schrader. Also, it stopped my brother asking if he could borrow my pump to fill his bike tyres - philistine.
Does that thing kinda look like a big cat to you?
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john bunsenburner
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Sat Feb 07, 2009 12:33 pm

Hey rag, i know there is a whole thread about this but for the record(and the two pumps beign built right now) what bore size do you recomend for the piston tube of the pump(in metric preferably).
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Gippeto
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Sat Feb 07, 2009 1:05 pm

@ Roughboy,

The "regular" air hose that I have is rated for 300psi and would be fine. Of course, as mentioned by Ragnarok, it has more volume internally (3/8"id).

DO NOT use hose intended for a gas welding rig, unless you can find a pressure rating for it first. My oxy/acetylene rig is only running around 10 psi to the hoses.

That being said, I use 1/4" hydraulic hose rated for 5800psi.


This might be of some help as well. :)

http://www.spudfiles.com/forums/easy-st ... 13277.html
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john bunsenburner
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Sat Feb 07, 2009 1:13 pm

Sorry for recomending was gas weling hoses, all th ones i found are rated 50 bar so i thought all where, sorry again!
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Gippeto
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Sat Feb 07, 2009 1:16 pm

Gippeto wrote:
unless you can find a pressure rating for it first.
Reading comprehension?
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john bunsenburner
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Sat Feb 07, 2009 1:20 pm

john bunsenburner wrote:so i thought all where
Same for you?
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Ragnarok
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Sat Feb 07, 2009 1:31 pm

john bunsenburner wrote:what bore size do you recomend for the piston tube of the pump(in metric preferably).
That entirely depends on the weight of the person in question and the pressure they want to reach.

I personally use a 20mm bore pump tube for my 300 psi pump, but I'm no longer a growing teenager (in body at least - in mind, that's a different matter), so I have a lot more mass to spare than those who are.
Does that thing kinda look like a big cat to you?
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john bunsenburner
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Sat Feb 07, 2009 2:09 pm

Well i weight 65kg and need about 50bar

50*14.5=725

725/25=29

143/29=4.9=>5


I would need a 5mm pump bore to get 50bar@65kg if i used all my body weight...
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Ragnarok
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Sat Feb 07, 2009 2:27 pm

Roughboy, in answer to your PM, the pump cylinder is 80 cm long, but it's been fixed at a 60 cm stroke.
The pump rod is just less than a metre in length.

EDIT: On a related note, I see my PM inbox is nearly full. Great, that means I'll have to go through it all again.
Does that thing kinda look like a big cat to you?
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