How to check accuracy of Kite/Wing pump

[PullStrings]

take in consideration this too

Hey got an idea
What do you think ?

Majority of people hand pumps kites & wings
Many don't trust or go by gauges

So what if kite manufacturers would supply the recommended air pressure by giving the customer the amount of liters of air to push into the LEI ?

So knowing your kite pump volume capacity that you're using and the amount recommended you could count the strokes

Fictional example
12m kite 5 struts suggested 250 Liters pumped in kite

Using 2.9L pump and do the whole kite in double action

250÷5.8= 43.1 strokes

Or pump 30 strokes in double action = 174L
Then finish the last 76L in single action =
76÷ 2.9= 26.2 strokes

So two ways here 43.1 or 56.2 strokes

Ha ha yes going a bit wild with numbers

That way you customized your way to pump and don't need gauge or other way to guesstimate pressure

Just an idea

Have a nice day

[Archer77]

take in consideration this too

Hey got an idea
What do you think ?

Majority of people hand pumps kites & wings
Many don't trust or go by gauges

So what if kite manufacturers would supply the recommended air pressure by giving the customer the amount of liters of air to push into the LEI ?

So knowing your kite pump volume capacity that you're using and the amount recommended you could count the strokes

Fictional example
12m kite 5 struts suggested 250 Liters pumped in kite

Using 2.9L pump and do the whole kite in double action

250÷5.8= 43.1 strokes

Or pump 30 strokes in double action = 174L
Then finish the last 76L in single action =
76÷ 2.9= 26.2 strokes

So two ways here 43.1 or 56.2 strokes

Ha ha yes going a bit wild with numbers

That way you customized your way to pump and don't need gauge or other way to guesstimate pressure

Just an idea

Have a nice day

not bad at all
they should give PSI and air liters too!
also if many are still struggling to publish the weights... maybe in future

[edt]

Majority of people hand pumps kites & wings
Many don't trust or go by gauges

So what if kite manufacturers would supply the recommended air pressure by giving the customer the amount of liters of air to push into the LEI ?

As a pump ages it puts less and less air into the kite. A brand new pump will do 4 liters per cycle but even after 6 months it's way down, maybe even 3.5 liters thanks to the lubricant and seals wearing out. That would put you at 1 psi less than you are supposed to get. I had that idea you know counting pump cycles and did it for a long time all I learned is that pumps wear out. It would be nice if they made a hand pump calibration unit, you know maybe $50, not something you or I would buy but every shop or store could own one, and you get your pump gauges tested once a year. A hand pump testing gauge wouldn't be something they would make money on it would just be something to produce that buys the goodwill of kiters.

[PullStrings]

@Edt
What you are saying about pump pushing less air as it ages might be true

It has not been my experience with my pump for last 3 years

Pumping all my kites with same pump that I do maintain real well by lubricating the seal with clear silicon grease every 2-3 months

By habit I do count my pumps especially with my large 17m and look at the gauge for 7 PSI

It does not change it is always the same...amount of strokes and PSI

I guess my pump behaves differently that what you have experienced

I do kitesurf a lot @ 180 sesh a year / @ 15 a month

Pump is 2.9 XL Core

Thanks you for your input !

[Archer77]

@Edt
What you are saying about pump pushing less air as it ages might be true

It has not been my experience with my pump for last 3 years

Pumping all my kites with same pump that I do maintain real well by lubricating the seal with clear silicon grease every 2-3 months

By habit I do count my pumps especially with my large 17m and look at the gauge for 7 PSI

It does not change it is always the same...amount of strokes and PSI

I guess my pump behaves differently that what you have experienced

I do kitesurf a lot @ 180 sesh a year / @ 15 a month

Pump is 2.9 XL Core

Thanks you for your input !

[Peter_Frank]

edt is right, pumps give less and less volume, tillthey eventually are useless, can take years, or less sometimes. .

Also, you have to pump all the way each stroke, hitting the bottom (easy) and the top of the pump (not so natural on mega pumps)
Which might be a bit tough on the pump so it læst shorter.

And if your get even the slightest "connection" leak at the valve, you can not use volume.

If pump pops out of the valve, you have to deflate, roll all air out of tube and struts, and start all over again

So going by feel, or your own pressure gauge knowledge even if it shows wrongly, is better I would say

Peter

[PullStrings]

Also, you have to pump all the way each stroke, hitting the bottom (easy) and the top of the pump (not so natural on mega pumps)
Which might be a bit tough on the pump so it læst shorter.

Here is my solution for that since i pump my kites on the sand using a tall pump
You bury your pump base 3 to 4 inches ....it will make your body position quite natural and allow for full upstrokes
Using your heel in soft sand or one of the pump's leg on hard sand... you dig out a trench of proper width and depth to set the pump base in it
Once base is set in trench fill up the gap over pump's feet with sand making it level with the rest of the beach to set your own feet over

I hope this tip can help someone

[Peter_Frank]

Hi everyone

I have been thinking about this now and then

Working professionally making measuring meters (Heat/Water/Electricity) so I have ALL possible options for measuring kite pumps.

Eventually made a small calibrated pressure gauge with an adapter so I could test some kite pump gauges

Did it today, and the picture shows the result

Found a few old pumps in the shed too, it doesnt matter if the sealing when pumping isnt tight - the gauge comparison is still perfect within the 2-3 % resolution accuracy.

Dont take the "brands" for granted as good or bad, IMO and experience it could and would just as well be "Chinese" differences in the same magnitude, if you took 5 pumps from the same brand and pump type - impossible to know.
Anyways, found that my 5 pumps were off by -11 to +20 %, and some were bullseye



Peter

[thewindego]

just pump it and feel if ok. Simple as that

[Peter_Frank]

just pump it and feel if ok. Simple as that

You dont have all the new wings I can read

With a kite it is easy when experienced yes, but when new and unexperienced, it is not

And for wings it is really important and not easy to feel as a totally different ballgame than kites

Anyways, it is besides the point, I would simply give feedback to those who has been thinking about how precise gauges really are, the OP at least.

Variation of 27 % at a given PSI between the 5 I tested, that is not "small values"

Peter