Best O-ring material for my electric hand pump?



Author Topic: Best O-ring material for my electric hand pump?  (Read 221 times))

Offline Atom

  • Shooter
  • *
  • Posts: 36
  • Real Name: Ante
Best O-ring material for my electric hand pump?
« on: January 17, 2019, 08:56:57 AM »
I have electric driven hand pump and with her fill small bottles  (2-7 liter) to 250-300 bar.

The problem is to get it fast overheats.
Which material and hardness you recommend?

She similar  looks like this
  • Croatia

Offline Atom

  • Shooter
  • *
  • Posts: 36
  • Real Name: Ante
Re: Best O-ring material for my electric hand pump?
« Reply #1 on: January 23, 2019, 08:38:02 AM »
Hello  8)
Please respond ...
  • Croatia

Offline Back_Roads

  • ???
  • GTA Senior Contributor
  • ******
  • Posts: 3806
  • Sentry 702-3 .22 40 FPE W/ 30 gr. BBT FN
    • https://www.facebook.com/pg/longshot/about/
  • Real Name: James Seiler
Re: Best O-ring material for my electric hand pump?
« Reply #2 on: January 23, 2019, 09:43:01 AM »
 I think Duro 90 is the toughest oring. If they do not hold well, then I would look into slowing the pump RPM, or stopping to lube with silicone oil more often. The Shoe Box compressors use a felt strip that wipes oil into the system with every stroke.
  • Wisconsin Collins ;Hunters Paradise; Theres a Sign in town to prove it :)
We Got The Guns !

Offline AlanMcD

  • Plinker
  • **
  • Posts: 278
  • yes
  • Real Name: Alan
Re: Best O-ring material for my electric hand pump?
« Reply #3 on: January 23, 2019, 11:13:39 AM »
Separate from the question on which o-ring to use, the issue of heat management on these multi stage hand pumps is critical.  They simply have no good way to dissipate heat when pumped fast.

The stages are "nested" inside of each other, so the most heat is generated in the middle of the pump.  That is why they need to only be used for about 50-60 strokes and then allowed to cool back down. This recommendation does not change when the pump is hooked up to a motor for automated pumping - the recommended duty cycle is for the pump and not the pumper. ;)

Even if you do replace the o-rings with ones that will last longer when run continuously, you will end up having a hotter air charge leaving the pump, and this ill carry more water vapor into the gun or tanks that you are filling.  That duty cycle of 50-60 strokes with time to cool down not only increases the life of the pump, but help to keep the air dry - it does this by keeping the air temperature cool enough after compression that water condenses out of the air charge to be vented out with the bleed valve.

Here is a post I made with illustrations of how the pump stages work.  Note that the high heat third stage is buried deep in the pump - no good way to cool it: https://www.gatewaytoairguns.org/GTA/index.php?topic=145448.msg1477494#msg1477494
  • Michigan

Offline Atom

  • Shooter
  • *
  • Posts: 36
  • Real Name: Ante
Re: Best O-ring material for my electric hand pump?
« Reply #4 on: January 23, 2019, 02:57:41 PM »
What do you think on Viton materijal ? I have a big filter with molecular sieve .
  • Croatia

Offline shorty

  • Expert
  • *****
  • Posts: 1632
  • yes
  • Real Name: Tim
Re: Best O-ring material for my electric hand pump?
« Reply #5 on: January 23, 2019, 06:17:15 PM »
  • Palm Coast, FL

Offline Atom

  • Shooter
  • *
  • Posts: 36
  • Real Name: Ante
Re: Best O-ring material for my electric hand pump?
« Reply #6 on: January 23, 2019, 07:17:09 PM »
I have a motorized hand pump as well.

at one point when filling bottles instead of just a gun I used these ice packs and wrapped them on the pump. Never got hot with the ice pack.

Good idea  :D
  • Croatia

GTA - The best place for discussion about Air Guns.