SpudFiles

Hey every one i have been recently been making a stirrup pump and i have been using Gippeto's easy stirrup pump instructions but for some reason the air escapes past the piston and out to where the handle goes, hopefuly you get what i mean. I have done everything correct but it wont work and it doesent pump out that much air unless its ament to do that. Also the check valve dosent really work either unless i missed some thing.
Any help any one, Ill also add some pictures tomorrow to give you guys a example of what every thing looks like.

yea we need pic, you probably did something wrong since his pump has been build by a few people and they worked out fine.

it sounds like you need a bigger O-ring for a better seal, but could be leaking in lots of other places.

the pump isn't meant to pump large volumes of air but to pump high pressure air, one thing you REALLY NEED to make sure IS STRONG is your CHECK VALVE if it brakes under pressure will turn into a massive air cylinder and smash anything in its way. Ask btb, when his failed it broke his jaw.

would it be easier if bought a check vavle?

Get some pictures up. This is a really simple project, and shouldn't be giving problems.

Yes. McMaster carries plenty of check valves that are rated to 1,000psi.

Sounds like you're having issues sealing both the check valve and the floating o-ring on the pump head. Pictures please?

well here are the pictures of the main parts that im having trouble with:

check valve with nothing in it:


The inner parts for the check valve and there is a lighter sping and a stronger spring and to valve parts but i dont know what would work best:


The gaps for the air to pass through:


The piston


The piston:


The piston:


Also if you need anymore pictures to get a better understanding tell me and ill take some more.
Edit:When i use the softer spring it leaks air and dosent have a good seal but when i use the harder spring it seals but the valve is harder to open.

You changed things a little bit to work with available materials?

What does your check valve seat on?....there's no washer in the fitting...is it on the end of the pump tube?

How close of a fit is the pump head in the tube?

Pics.

A check valve should have the weakest spring possible that will still seal. I highly purchasing a high-pressure check valve. You'll probably never be able to match their incredibly low cracking pressure.

Is the washer that the o-ring seals to polished? Did you seal the threads on the pump head? (This design is somewhat unfamiliar to me, so I may be asking obvious questions.)

@ Gippeto: I dont think ill make the check valve but ill buy one in stead to be on the safe side and to just make life easier, Also the pumps head is about .5 of a millimeter gap between the pump head and copper pipe and ill upload some pics of the head and the copper pipe.