O2 clean SP reg

[Packhorse]

I need an O2 reg.
Currently I have a MK10 and a MK20.
Can I clean these and use standard parts kit? Should I use Viton O rings and the standard HP seat? or do I need a proper O2 service kit?
I see there is a O2 kit on ebay for the MK10 but it does not show a HP seat, only O rings.

 

[pescador775]

The standard seat is OK. Off the shelf kits normally include a 1st stage seat but you are not looking at a a rebuild kit, it is an O2 conversion kit. Don't use viton O rings for SP moving parts (this has been discussed recently on SB). The Scubapro mechanism will only function reliably if factory or equivalent parts are used. In any case, the mechanical properties of "O2" rubber may not be as good as factory standard materials. For the DIY, one can use EPDM or urethane for the valve stem and urethane for the piston head. However, standard SP rings should last a long time in O2. If DIY, you must first determine the hardness of factory rings. My guess, 70 duro for all.

 

[DA Aquamaster]

SP switched to EPDM o-rings a few years ago so a new Mk 10 annual service kit will include EPDM o-rings. There are however several static o-rings that should be replaced. Most are generic LP and HP port o-rings while the swivel cap is not and would need to be matched with a suitably sized o-ring from a third party source. I have not ordered one from SP lately and I am not sure if they are selling old stock nitrile o-rings or if these are now also EPDM. It is a low pressure o-ring and is dynamic only in the broad sense of the word as the swivel turns, so a 70 duro o-ring should work fine.

I agree that viton o-rings are not a good choice for the piston head and piston stem o-rings - they do not wear well and both are prone to damage during assembly in the Mk 10. I have also found that viton o-rings do not hold up as well when used in the LP and HP ports. At best they are very demanding in terms of proper lubrication.

 

[Packhorse]

I have a service kit # 10500041 for the MK 10 It has 3 HP seats and 3 Orings plus filter.
And also repair kit #10750041 for the MK20. Are these OK to use? Im am unsure how old they are as I brought them from an EX SP importer. The only date I can find is 05/00 whick seems to be the date which the card showing kit part numbers on one side and O ring sizes on the other.

 

[Couv]

Hello Packhorse,

You mentioned that you need an O2 regulator. Do you mean 100% O2? If so, in addition to what the gurus above have posted, please remember that you must O2 clean all components, usually Simple Green or a dish detergent such as Joy or Dawn will do. AND you must use an O2 compatible o-ring lubricant such as Krytox or Christolube. Cristolube is the lube most often recommended by regulator manufactures and can be purchased on the internet easily (probably less expensive too.)

See http://www.scubaboard.com/showthread.php?t=172952&highlight=o2+clean

and
http://www.diveriteexpress.com/hardware/orings.shtml#prices

As mentioned above, EPDM O-rings are a better choice than Viton.

If you do not need your regulator for 100% O2 use, the cleaning process is the same, but you can get away with a less expensive lubricant.

Sorry, I am not familiar with the kits.


couv

 

[DA Aquamaster]

Current EPDM o-rings usually have a white stripe on them. Older nitrile Scubapro o-rings came in several different colors as the color coding was a means of knowing what was what.

A Mk 20 kit would pre-date the switch to EPDM o-rings. The Mk 20 had a special nitrox kit that when used in a properly cleaned regulator allowed the use of 100% O2 at up to 3500 psi.

Current Mk 25 kits (within the last 3-4 years) should have EPDM o-rings. The same is true of Mk 10 annual service kits, but again, you will need to replace all the other o-nitrile rubber o-rings in the first stage and O2 clean it if you plan to use it with O2 mixes in excess of 40%.

With regard to lubricants, Christolube is a much better lubricant than silicone grease and the cost is not really all that great. And for O2 applications using Christolube is essential and silicone grease is petroleum based. MCG 111 is better for dynamic o-ring lubrication while MCG 129 is designed for general lubrication, although either one works for general use and both are better than silicone. Peterbuilt charges $22 for a 2 oz tube of MCG 129 and $29 for a 2 oz tube of MCG 111, compared to $11.00 for 2 oz of Dow Corning silicone lubricant.

 

[Packhorse]

Thanks guys. I have a tub of 129 christolube. I just need to find a supplier for the hp and lp port O rings.
I need it clean for deco use so 50%-100%

 

[do it easy]

I have a tub of the MCG 129 and it has an expiration date on it. Does this stuff go bad? Is it that just a ploy to keep me buying it on a regular basis, like the lather, rinse, repeat directions?

 

[Hoosier]

With regard to lubricants, Christolube is a much better lubricant than silicone grease and the cost is not really all that great. And for O2 applications using Christolube is essential and silicone grease is petroleum based. MCG 111 is better for dynamic o-ring lubrication while MCG 129 is designed for general lubrication, although either one works for general use and both are better than silicone. Peterbuilt charges $22 for a 2 oz tube of MCG 129 and $29 for a 2 oz tube of MCG 111, compared to $11.00 for 2 oz of Dow Corning silicone lubricant.

As I recall correctly, MCG 111 is ScubaPro manufacture recommendation and MCG 129 is Apeks recommendation... Is it right?


Tony, as long as there is no discolation, it will be fine.

 

[Couv]

I have a tub of the MCG 129 and it has an expiration date on it. Does this stuff go bad? Is it that just a ploy to keep me buying it on a regular basis, like the lather, rinse, repeat directions?

I am afraid your Crisco has expired. Send it to me along with any equipment you have applied it to and I will see that it is disposed of properly.

couv