Safest O-ring material

[Vapomans]

Hi!

Want to order o-rings for all my vapes but I’ve gotten tired of paying premium prices from the vape manufacturers so would like to buy them in bulk straight from the o-ring mafia.
Was reading a bit about materials and their uses and found this page. Was thinking that FFKM and Silicone seem to be the best materials. But when I go to order I can choose between all of these:

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Image 68-AACA53-C581-4-A4-B-ADBA-77233-A646-BD8 hosted in ImgBB

ibb.co

What Material should I choose dear wise FC fam?

Cheers

 

[GoldenBud]

FFKM is used mainly in chemical reactors (FFKM is super expensive) , dunno about vaporizers. Buna Nitrile is enough for the stem's rings, Silicone rubber is up to 500F hence is fine for the Dynavap tip's O-Ring.

If you need O-Rings for Dynavap:
008Q
X Rings Size 008 Minimum 10 pcs

007Q
X Rings Size 007 Minimum 10 pcs


61MMS
Silicone O-rings 6 x 1mm Minimum 10 pcs

X Rings Size 008 Minimum 10 pcs

3/16 ID x 5/16 OD x 1/16 CS - Price for 20 pcs

www.oringsandmore.com

X Rings Size 007 Minimum 10 pcs

5/32 ID x 9/32 OD x 1/16 CS - Price for 20 pcs

www.oringsandmore.com

Silicone O-rings 6 x 1mm Minimum 25 pcs

18mm ID x 22mm OD x 2mm CS - Price is for 5 pcs

www.oringsandmore.com

You'll never reach 600F-650F in a vaporizer (except desktops, no rings needed) . hence you don't need a FFKM ring.

you can get FKM rings:

FKM X Rings Size 007 Minimum 2 pcs

3/16 ID x 5/16 OD x 1/16 CS - Price for 20 pcs

www.oringsandmore.com

FKM X Rings Size 008 Minimum 2 pcs

3/16 ID x 5/16 OD x 1/16 CS - Price for 20 pcs

www.oringsandmore.com

FFKM will be super expensive

 

[bhasma]

Nitrile is more resistant to abrasion and compression, but not temperatures over 120°C. While FKM is resistant to temperature up to 220°C.

 

[LesPlenty]

I got a food safe VMQ multi sized o-ring kit for experimenting/fixing/replacing and they are supposedly rated to 230°C... Google on VMQ,

What is the temperature range of Vmq silicone?
-60° F to 400° F
Silicone (VMQ) Advantages:
Temperature range of -60° F to 400° F with some formulations up to 450° F. Physiologically neutral properties.

 

[bhasma]

EPDM, FKM, VMQ and NBR are all used in food safe and medical applications. NBR is not resistant to isopropanol, and the relative safety of the others depends on temperature. FKM and VMQ are resistant to similarly high temperatures (depending on formulation), but VMQ is less resistant to abrasion. And the very high temperature range of FFKM (up to 320°C) perhaps makes it the "safest" material, but for most applications (as GoldenBud noted) that margin is probably not worth the additional expense.

 

[Texus]

Good stuff. Now just need to figure out the size my Lotus WPA and some other devices use, both thickness and diameter...

 

[cosimo]

So, I've been looking for the best oring material to put an oring on the heater of my Enano XL and improve sealing of the stem without using the top basket screen on the stem (or put the oring on the basket screen to seal it better to the stem as shown here https://fuckcombustion.com/threads/e-nano-xl-from-epicvape.52210/page-17#post-1763329). Doing some research i found more info that might be usefull for those also looking into oring materials.
Also, not sure it applies to vapor or to our usage on vaporizers, but it seems VQM/silicone and FKM have a lower max heat resistence than normally stated when talking about steam. From https://nh-oring.de/en/fkm-o-rings-materials-simply-explained/ :

A comparison of the most important O-ring materials​

Material	Temperature resistance	Chemical resistance	Elasticity
NBR	-30°C to +120°C / -22°F to +248°F	Low	High
HNBR	-30°C to +150°C / -22°F to +302°F	Medium	High
EPDM	-45°C to +150°C / -49°F to +302°F	Medium	High
SILICONE	-60°C to +200°C / -76°F to +392°F	Low	High
FKM (VITON)	-25°C to +200°C / -13°F to +392°F	Medium	High
FEP coated	-60°C to +200°C / -76°F to +392°F	High	Medium
PTFE	-250°C to +250°C / -418°F to +482°F	High	Low
FFKM	-40°C to +340°C / -40°F to +644°F	High	High

Hot water or steam is a much more aggressive medium than it appears. Basically, the temperature resistance of a material (e.g. on data sheets) is only valid for the medium of air . In our experience, many users do not know that the material temperature resistance only applies to air.
If we now assume hot water or steam as the medium, the maximum temperature resistance is significantly reduced.
As a guide for the hot water or steam resistance of O-ring materials we have compiled a table for you. Please note that these are approximate values. In particular, if your application should reach the limits of the material temperature limits, a precise test is necessary.
Important: When considering the maximum temperature resistance of a material, the saturation content of the water vapor must always be taken into account. The specified values are based on 100% saturated water vapor.

Material	Temperature resistance air	Temperature resistance steam
NBR	120°C / 248°F	80°C / 176°F
VMQ (silicone)	200°C / 248°F	100°C / 212°F
FKM (VITON)	200°C / 248°F	120°C / 248°F
EPDM	150°C / 302°F	170°C / 338°F
FEP coated	200°C / 248°F	200°C / 248°F
PTFE	200°C / 248°F	200°C / 248°F
FFKM - ECOLAST NH5750	270°C / 518°F	210°C / 410°F
FFKM - ECOLAST NH5751 HT	330°C / 626°F	230°C / 446°F
FFKM - ECOLAST NH5755 HT	330°C / 626°F	260°C / 446°F

 

[Piecho]

Hmm, so for the dynavap you suggest to go with ffkm instead of silicone? I did order silicone ones anyway, can leave the report here after testing.

 

[cosimo]

From what Ive gathered the best would be FFKM but it can be quite expensive... but might be worth the peace of mind?
The next best would be FKM closely followed by Silicone. In my case I will try to see if I can find a reasonable priced FFKM ... if not Ill just get a FKM. I think for the Dyna any will work.

 

[Vapomans]

So, I've been looking for the best oring material to put an oring on the heater of my Enano XL and improve sealing of the stem without using the top basket screen on the stem (or put the oring on the basket screen to seal it better to the stem as shown here https://fuckcombustion.com/threads/e-nano-xl-from-epicvape.52210/page-17#post-1763329). Doing some research i found more info that might be usefull for those also looking into oring materials.
Also, not sure it applies to vapor or to our usage on vaporizers, but it seems VQM/silicone and FKM have a lower max heat resistence than normally stated when talking about steam. From https://nh-oring.de/en/fkm-o-rings-materials-simply-explained/ :

A comparison of the most important O-ring materials​

Material	Temperature resistance	Chemical resistance	Elasticity
NBR	-30°C to +120°C / -22°F to +248°F	Low	High
HNBR	-30°C to +150°C / -22°F to +302°F	Medium	High
EPDM	-45°C to +150°C / -49°F to +302°F	Medium	High
SILICONE	-60°C to +200°C / -76°F to +392°F	Low	High
FKM (VITON)	-25°C to +200°C / -13°F to +392°F	Medium	High
FEP coated	-60°C to +200°C / -76°F to +392°F	High	Medium
PTFE	-250°C to +250°C / -418°F to +482°F	High	Low
FFKM	-40°C to +340°C / -40°F to +644°F	High	High

Hot water or steam is a much more aggressive medium than it appears. Basically, the temperature resistance of a material (e.g. on data sheets) is only valid for the medium of air . In our experience, many users do not know that the material temperature resistance only applies to air.
If we now assume hot water or steam as the medium, the maximum temperature resistance is significantly reduced.
As a guide for the hot water or steam resistance of O-ring materials we have compiled a table for you. Please note that these are approximate values. In particular, if your application should reach the limits of the material temperature limits, a precise test is necessary.
Important: When considering the maximum temperature resistance of a material, the saturation content of the water vapor must always be taken into account. The specified values are based on 100% saturated water vapor.

Material	Temperature resistance air	Temperature resistance steam
NBR	120°C / 248°F	80°C / 176°F
VMQ (silicone)	200°C / 248°F	100°C / 212°F
FKM (VITON)	200°C / 248°F	120°C / 248°F
EPDM	150°C / 302°F	170°C / 338°F
FEP coated	200°C / 248°F	200°C / 248°F
PTFE	200°C / 248°F	200°C / 248°F
FFKM - ECOLAST NH5750	270°C / 518°F	210°C / 410°F
FFKM - ECOLAST NH5751 HT	330°C / 626°F	230°C / 446°F
FFKM - ECOLAST NH5755 HT	330°C / 626°F	260°C / 446°F

Wow that’s a great investigation finding. This is what I kind of suspected coming from an engineering background. That’s why I wanted to go with FFKM from the get go after doing some research. But the prices of those are hard to swallow.

 

[Radwin Bodnic]

Reading the charts above made me a little anxious about the Viton o-rings holding the injector glass on the herbo Ti.

So I measured with a type K thermocouple after a 20min heat soak (perfectly stabilized temp.)
@5 on the old analog dial the heat diffuser should be at 330°C according to the manual.
I only had 300°C inside the rib of the heat diffuser. But I know my probe is low by 10°C and that the glass housing (removed for the measure) could totally bring the needed insulation to get the Ti 20°C hotter.

It should be between 7V and 8V with a VVPS.

The ledge where the o-rings sits however only was under 110°C. So perfectly safe for the provided Viton orings.

This was predictable since Ti anodizes itself with temperature, and that the part where the orings sits does not anodizes, no matter how hot you set the Ti. (Heat diffuser and core does anodize.)

 

[howie105]

I am a big fan of 70A durometer silicone o-rings (red ones) as impact bumpers, hose stiffeners (less kinking) sealing etc. I positioned one to be in contact with my ballers heating coil to see if it would degrade, and it took a couple of months to die. So I try to keep the o-rings out of the hot first third of the vapor path.