Tiny "breather?" Hole In Some Fp Caps

[indigirl]

While reading this discussion about the Noodlers flex pen, which includes some folks wondering if the problems were due to the hole in the cap, I remembered that I have often wondered about these little holes that are in some of my pen caps. What are they for? Why do only some pens have them? Will someone please enlighten me? I do notice that my pens with the holes experience more start-up problems than the pens without the holes. Whatever the benefit of the hole may be, it's eluding me... :hmm1:

[AltecGreen]

The breather hole is there to rapidly equalize the pressure when you uncap the pen. Otherwise, you create a vacuum that can suck the ink from the pen into the cap.

 

The hole is located below the inner cap of the pen.

[Hugh200au]

A lot of modern pens have a vented lid ( as opposed to those to equalize pressure) as a safe guard against children ( or adults for that matter) choking on a swallowed cap, it's part of the design rules for pen caps (in some parts of the world anyway). For example : English made Parkers the vent is under the top of the clip, a major reason why the nibs dry out.

 

Regards

Hugh

[indigirl]

Wow. All quite mind-expanding :blink:

 

Does this mean that the pens that look to be without holes actually do have holes, but they are just hidden better?

[Paddler]

Wow. All quite mind-expanding :blink:

 

Does this mean that the pens that look to be without holes actually do have holes, but they are just hidden better?

 

Not necessarily. Some pens just don't have vent holes at all. My P51 has no vent hole. Neither do several of my Sheaffer pens.

 

I don't really believe the vent holes are installed to prevent choking. To do that, the vent would almost have to be in the end of the cap. Also, it would have to be nearly the size of the cap itself to allow enough air to pass. Try it. Breathe through that little hole and see how long you can hold out. (Just don't inhale the cap. You wouldn't want to find out the hard way.)

 

Paddler

[AltecGreen]

Wow. All quite mind-expanding :blink:

 

Does this mean that the pens that look to be without holes actually do have holes, but they are just hidden better?

 

 

No. Most modern pens do not have breather holes since the feed designs are different. The fins and/or a collector on a feed help alleviate the problem.

[geoduc]

Thanks for asking the question, indigirl. I had wondered about those holes as well.

[Hugh200au]

Wow. All quite mind-expanding :blink:

 

Does this mean that the pens that look to be without holes actually do have holes, but they are just hidden better?

 

Not necessarily. Some pens just don't have vent holes at all. My P51 has no vent hole. Neither do several of my Sheaffer pens.

 

I don't really believe the vent holes are installed to prevent choking. To do that, the vent would almost have to be in the end of the cap. Also, it would have to be nearly the size of the cap itself to allow enough air to pass. Try it. Breathe through that little hole and see how long you can hold out. (Just don't inhale the cap. You wouldn't want to find out the hard way.)

 

Paddler

 

Wrong , the design rules to avoid chocking are quiet specific. Note the "Ventilated caps air flow" of 8 l/minute .

 

Regards

Hugh

 

 

[Hugh200au]

Wow. All quite mind-expanding :blink:

 

Does this mean that the pens that look to be without holes actually do have holes, but they are just hidden better?

 

 

No. Most modern pens do not have breather holes since the feed designs are different. The fins and/or a collector on a feed help alleviate the problem.

 

Most modern pens do have breather hole to prevent chocking. Pen caps have killed a lot of children over the years and the design rules are simply to reduce or eliminate that problem.

[mholve]

An unscientific test based on the pens I have handy:

 

Italian:

Aurora: Not vented

Delta: Not vented

 

American:

Cross: Not vented

 

Asian:

Danitrio: Vented

TWSBI: Not vented

 

German:

Rotring: Vented

Pelikan: Vented

[Bo Bo Olson]

How unobservant of me.

I thought them all vented.

 

Not Vented....

Pelikan '90 400 Sovereign, 140, '80's 100?, 120, 400NN and 605..

Geha 725, piston 'Clipper' not vented. None of my Metal pens or metal capped are vented . MB 320, Osmiroid, Lamy Joy, Sheaffer Calligraphy pen, Reforms.

 

Vented

Kaweco-Mercedes, Mercedes with three vent holes, Geha 790, Osmia, Osmia-Farber-Castell, Boehler of course being 'Osmias', Columbus (Italian), Esterbrook, Wearever and MB 234 1/2 Deluxe are vented. Rusewe also

 

My Manuscript pen, has six huge holes around the center of the top flat of the cap....so that must be real modern....a ninja could hide in an oil barrel with that cap above oil and breath just fine. Oddly I could not see light through it.

 

It is the only child safe cap I got...cause the old pens out side that Mercedes had only one little bitty hole in them, needle size.

They were made before lawyers ruled the world.

So was that Mercedes with three holes...

 

 

Got to make sure you poke all that wax out of the breathing holes.

 

Blind as a bat...I could have lost a beer bet easy. I was sure my plastic pens were vented.

Edited January 12, 2011 by Bo Bo Olson

[ticoun]

none of my pens have vented caps. not even a hole in the sheaffer 330's inner cap.

[Ernst Bitterman]

I was examining a Parker Reflex in regard to this phenomenon, and here's an interesting test. Stick the cap in one of your breathing holes with the pen absent and blow through it-- something in the order of 8L/min, I suppose. Now, stick the pen in the cap, put the top of the lid in ye blow-hole, and try again. I found almost no air passage, because the inner cap is mounted in such a way as to let air pass around it, but still (very nearly) seal the point against the air.

 

Of course, the Reflex is kind of sucky, so it isn't a great seal. There's actually a little notch in the outside of the inner cap of a "51" that performs the same agency as the vent holes in a screw-cap pen, because the clip and screw which hold it don't make an air-tight seal themselves. Most pens have something like this to keep the ink from being drawn out, so they don't rely entirely on the collector/feed vanes.

 

edit-- y'know, I was going to mention Sheaffers as a having a lot of exceptions to the rule; they seem to rely on the fact the the distance between sealed and not sealed is VERY small and the feed having a lot more buffering than you think it does.

 

other edit-- I've just tried the same trick with the Phileas I'm carrying today, and I don't think I'd get even one liter of air through it in a minute, pen in the way or not. but blue rather than green.

Edited January 12, 2011 by Ernst Bitterman

[indigirl]

Wow & wow again! Now I am really glad I asked... I had no idea how complex the answer(s) would be! Just another day in the FP Nuthouse... I can always count on y'all to have an interesting discussion about almost anything, as long as it has to do with fountain pens. :meow:

[Tadeusz]

Hugh-- I believe that the pens that actually have a hole that you can breath through are those (shudder) cheap BIC ballpoints with the massive hole in the top of the cap.

 

Otherwise, those little pin-sized holes are so a vacuum is not created

[humsin]

I don't think the hole is for equalizing pressure, I mean, if you unscrew a pen, pressure should well be equalizing already.

[Bo Bo Olson]

They put the holes there for some labor costing reason...even before snorkel laws.

[Bigeddie]

Parker Sonnet cap holes seem excessively large, its a vent that encircles the very top of the cap; I am sure that it causes me some dryout / hard start issues.

 

My Lamy 2000 has the opposite problem, the lack of a vent causes the ink to be sucked out when uncapping when it is less than half full. I assume that this is because of the pressure difference between the air behind the ink in the chamber and the brief lower pressure in the cap. This issue has caused me to all but stop using my Lamy 2000s It's on my desk at the moment while I consider whether the enjoyment of it's use is worth the heartbreaking moment I get covered with Tuski-yo.

 

From a performance perspective, the ventless screw cap seems to be the way to go. Having a £100+ pen is also a good motivator for keeping them out of the reach of children (and not sticking the cap in your mouth)!