Notos losing some psi between shoot sessions

[Perle]

Gentleman, Are any of you guys experiencing any air loss between shoot sessions ?

I believe I’ve seen a drop of only 200-250 over the course of 6 days

I didn’t just fill it and store it ( as the filling heats up tube raises pressure ) shot it … stored it at 2900 and came back to 2700 in 5-6 days


Anyone seeing any of that ?

 

[Sqwirl57]

Spray some soapy water around the gauges and anywhere else there may be seals. The bubbles will show you the leaks

 

[smythsg]

Any significant changes in temperature in those 5-6 days? I store my rifles in a room that is 10-15 degrees cooler than most rooms in my house and I can see the same type of drop if a cold snap comes down from the North and hits that room.

 

[Perle]

I’m in Florida but my gun room is 69 degrees.
It just odd to me.

I’m hoping it is that.

 

[doninva]

Expansion and contraction. Normal

 

[Stan’s boy John]

That’s a loss of 6.9% from 2900 psi over 6 days. I’ve never owned a PCP before but that seems to be a little excessive. I’d try the soapy water method. Might be leaking from around one of those crappy gauges.

 

[nobody1]

All PCPs leak sooner or later.
They all have many o rings which get bad after some time.

My .177 Nova Vista Liberty in 24 hours will leak until it gets to around 1000-1500 PSI and then it stops leaking.

I am glad I have a compressor and I can fill that gun (in less than 2 minutes) to about 4000 PSI just before I shoot it.

 

[Perle]

All PCPs leak sooner or later.
They all have many o rings which get bad after some time.

My .177 Nova Vista Liberty in 24 hours will leak until it gets to around 1000-1500 PSI and then it stops leaking.

I am glad I have a compressor and I can fill that gun (in less than 2 minutes) to about 4000 PSI just before I shoot it.

True but of the 9 PCPs I have. Non are leaking …
Some are over a decade old

Pcps are not designed to leak ….

Sorry I was just trying to see if others are having any issue on their Notos.

 

[JEHolloway]

My new Notos is dropping 200 lbs in three days of sitting.

 

[LMNOP]

Small air cylinder with temperature swings equals big pressure change. Larger cylinder with same temperature changes equals small pressure change. Boyles and Charles law — smaller cylinder means less volume.

I own a Notos and the above math checks out

 

[Sqwirl57]

Also worth noting that as the air is compressed it heats up. Once its been in the gun for a bit it cools down and you'll lose some pressure as well. I'd think you'd be able to top it back off after it cools down to get some pressure back.

 

[Dr. Kralenstein]

Idk, I don't own a notos, but none of my guns leak any air as long as I've let them sit and cool down. They'll drop a bit from cooling, but they stay put until I shoot them again.

 

[Perle]

Small air cylinder with temperature swings equals big pressure change. Larger cylinder with same temperature changes equals small pressure change. Boyles and Charles law — smaller cylinder means less volume.

I own a Notos and the above math checks out

I want to believe this.
unless others confirm theirs are doing the same …. It doesn’t make sense. ( it’s a 15 degree flux ).



Just like Boostcreep said … non of my other PCPs lose a drop it seems.

 

[Perle]

Idk, I don't own a notos, but none of my guns leak any air as long as I've let them sit and cool down. They'll drop a bit from cooling, but they stay put until I shoot them again.

Exactly.

Love the Notos I’ll take photos across 3 days and see

I’d exchange it if is this islolated .

 

[Hateful McNasty]

I want to believe this.
unless others confirm theirs are doing the same …. It doesn’t make sense. ( it’s a 15 degree flux ).



Just like Boostcreep said … non of my other PCPs lose a drop it seems.

Where you are fill it during the heat of the day hot and then put it in your refrigerator for a hour or 2 to cool it nice and see what you get..lol .

 

[LMNOP]

With respect to my comments relating to pressure and volume, in case it helps, https://chem.libretexts.org/Bookshelves/General_Chemistry/Map:_A_Molecular_Approach_(Tro)/05:_Gases/5.03:_The_Simple_Gas_Laws-_Boyles_Law_Charless_Law_and_Avogadros_Law

Pressure loss is excerabated when the volume is low comparatively... "The volume of a gas is inversely proportional to its pressure and directly proportional to its temperature and the amount of gas."

Filling my Notos I go from ~3600 PSI to ~3000 PSI very quickly. Remember, due to entropy exchange, the receiving vessel heats and the donor vessel cools. This is the entire principle behind the expansion valve used in the HVAC cooling closed-loop system. The heat causes gas expansion in a contained volume which drives pressure up per Boyles and Charles law. When the air cylinder cools, to ambient, the pressure loss is exacerbated by the lack of abundant volume.

Unless you have a unique problem (and you may, I am not discounting that) all of this may just fall into the realm of Physics. "My other PCPs" don't really come into bearing here unless they have a similar sized air cylinder.

I sincerely hope this information helped as my intent is to help. I am by no means claiming you have no leak nor that you are incorrect. I am just offering data points to consider.

 

[Perle]

With respect to my comments relating to pressure and volume, in case it helps, https://chem.libretexts.org/Bookshelves/General_Chemistry/Map:_A_Molecular_Approach_(Tro)/05:_Gases/5.03:_The_Simple_Gas_Laws-_Boyles_Law_Charless_Law_and_Avogadros_Law

Pressure loss is excerabated when the volume is low comparatively... "The volume of a gas is inversely proportional to its pressure and directly proportional to its temperature and the amount of gas."

Filling my Notos I go from ~3600 PSI to ~3000 PSI very quickly. Remember, due to entropy exchange, the receiving vessel heats and the donor vessel cools. This is the entire principle behind the expansion valve used in the HVAC cooling closed-loop system. The heat causes gas expansion in a contained volume which drives pressure up per Boyles and Charles law. When the air cylinder cools, to ambient, the pressure loss is exacerbated by the lack of abundant volume.

Unless you have a unique problem (and you may, I am not discounting that) all of this may just fall into the realm of Physics. "My other PCPs" don't really come into bearing here unless they have a similar sized air cylinder.

I sincerely hope this information helped as my intent is to help. I am by no means claiming you have no leak nor that you are incorrect. I am just offering data points to consider.

I may be wrong entirely …. I want to be.

Perhaps I should “ cool my jets “.

Thank you for the explanation. That’s exactly what I was looking for and this makes sense.

Love my Notos. It went right to the front of the pack of my carbines.

I use to work in service at a local dealership. Everytime the temp dropped by like 25 degrees everyone is showing up because thier tire pressure light is on


I’ve never had a gun with this small of a tank. Live and learn.

Thanks again LMNOP

 

[LMNOP]

…. It doesn’t make sense. ( it’s a 15 degree flux ).

250 bar, 80 cm3 of volume at 90 F is 0.78 moles.
0.078 moles of gas, with 80 cm3 of volume, at 75 F is 240 bar.

At 15 F of temperature delta the pressure loss is 145 PSI. Now bear in mind it's probable the air cylinder during filling is probably hotter than 90F but I have not put the FLIR camera I own on it yet.

When I fill mine I top it off where the green meets the red, if I let it sit, as I have now overnight, it's back to 3000 PSI and holds there +- some pressure as the temperature changes during the day. Really hope this helps.

 

[Perle]

250 bar, 80 cm3 of volume at 90 F is 0.78 moles.
0.078 moles of gas, with 80 cm3 of volume, at 75 F is 240 bar.

At 15 F of temperature delta the pressure loss is 145 PSI. Now bear in mind it's probable the air cylinder during filling is probably hotter than 90F but I have not put the FLIR camera I own on it yet.

When I fill mine I top it off where the green meets the red, if I let it sit, as I have now overnight, it's back to 3000 PSI and holds there +- some pressure as the temperature changes during the day. Really hope this helps.

Absolutely my friend.
My sphincter is relaxed now.
Pressure is stable but I’ll keep an eye on it just the same.

As I’ve said I just wanted to understand and compare with other Notos owners

Notos ftw

LMNOP

 

[LMNOP]

Hahhaah -- 100%, Notos FTW! Very happy to help good sir!