Scubapro "EVO"

[poolecw]

Ok, I know what EVO stands for but what does it add over the non EVO older models? I'm looking at picking up a uses MK25 off ebay.

 

[Duglum]

The spring (and maybe some other stuff) is coated with some kind of plastic on the EVO Models. That's the blue stuff you see on pictures.
It's supposed to prohibit ice buildup on the spring.

No idea if it actually works, but for cold water i'd go for it over the non-evo.
Have two Mk25 Evo with G260s... no problems at all in 4°C Water.

 

[shurite7]

The EVO has the extended thermal insulating system, the blue mentioned above. It does not prohibit ice build up; rather it delays the conditions that leads to ice formation. Any first stage can experience ice buildup under the right conditions and duration. It doesn't change the performance of the reg. For cold water divers it is a nice feature. I've had mine underneath the ice with no issues.

 

[poolecw]

Thanks guys. So for a diver that never dives in water below 60 f, a non EVO MK25 would work just as well?

 

[shurite7]

Thanks guys. So for a diver that never dives in water below 60 f, a non EVO MK25 would work just as well?

Yes, a non-EVO will be fine. Have fun.

 

[lexvil]

I’ve dived in water 47° with a standard mk25 with no issue, I wouldn’t expect any issues.

 

[stuartv]

The EVO has the extended thermal insulating system, the blue mentioned above. It does not prohibit ice build up; rather it delays the conditions that leads to ice formation.

It's more than just the blue coating on the spring. There are plastic pieces inside that separate metal pieces from what would otherwise be metal to metal contact. The plastic pieces are supposed to slow heat transfer.

Also, there is one part that specifically is to prevent ice buildup - a squishy O-ring on the piston shaft (IIRC). This O-ring flexes (squishes) a fair bit on each inhale/exhale cycle with the idea that if ice starts to form around that area, the flexing will break it up.

I have no idea how effective it is. I just know that is the intended purpose that was explained to me.

The EVO doesn't prevent freezing. It just makes it take longer to freeze, compared to the non-EVO model. The ScubaPro instructor in my tech class last week said the Mk 25 EVO is the first reg ScubaPro has ever stated is just as cold-tolerant as the Mk 17 (a sealed diaphragm model).

 

[buddhasummer]

It's more than just the blue coating on the spring. There are plastic pieces inside that separate metal pieces from what would otherwise be metal to metal contact. The plastic pieces are supposed to slow heat transfer.

Also, there is one part that specifically is to prevent ice buildup - a squishy O-ring on the piston shaft (IIRC). This O-ring flexes (squishes) a fair bit on each inhale/exhale cycle with the idea that if ice starts to form around that area, the flexing will break it up.

I have no idea how effective it is. I just know that is the intended purpose that was explained to me.

The EVO doesn't prevent freezing. It just makes it take longer to freeze, compared to the non-EVO model. The ScubaPro instructor in my tech class last week said the Mk 25 EVO is the first reg ScubaPro has ever stated is just as cold-tolerant as the Mk 17 (a sealed diaphragm model).

I very much doubt that. Equal cold tolerance I mean.

 

[shurite7]

It's more than just the blue coating on the spring. There are plastic pieces inside that separate metal pieces from what would otherwise be metal to metal contact. The plastic pieces are supposed to slow heat transfer.

Also, there is one part that specifically is to prevent ice buildup - a squishy O-ring on the piston shaft (IIRC). This O-ring flexes (squishes) a fair bit on each inhale/exhale cycle with the idea that if ice starts to form around that area, the flexing will break it up.

I have no idea how effective it is. I just know that is the intended purpose that was explained to me..

The "squishy o-ring" has been with the Mk25 for quite sometime. It is called the TIS, Thermal Insulation System. It works quite well.

The spring has a blue coated spring and two blue "caps" that keep the spring from direct contact with the metal body of the first stage. Hence the EVO.

To add even more, the cap of the Mk25 looks like it has cooling fins, looks similar to cooling fins on an engine, or, as I call them, ridges. The ridges help to slow the growth of ice on the outside. In my experience the Mk25 (both non-EVO and EVO) works very well in cold fresh water mountain lakes.

Last winter I was in the water diving and one person in our group experienced a freeze up with his reg. The Mk25EVO/G260 held up fine. The water temp was 35°F. His reg was an environmentally sealed diaphragm reg (non ScubaPro). The reality is his second stage is what created the free flow.

Many people who begin diving in cold water become so focused on the first stage they forget about the second stage. Be sure to get a second stage that can handle cold water.

 

[scubadada]

I’ve dived in water 47° with a standard mk25 with no issue, I wouldn’t expect any issues.

I have also dived a standard MK25 at 47 degrees, never even thought about it