Question Scubapro MK18

[axxel57]

The Upgrade Kits are still available, at least in Europe, SP order number here is 10.116.030
The old valve configuration had been notorious for its IP creeping which doesn't mean that you can't use it, but it's recommendable to upgrade.
If I could get the MK18 for a decent price, I would take it anyway, it's a solid piece of engineering and SP History. It was the first diaphragm 1st stage that had a similar air output as the SP Piston 1sts ( 8000l/min) and I wouldn't know another manufacturers 1st which could compete with this number end of the last century ( okay, who needs that much air anyway?).
And sure it is not just a MK16 with a turret as a MK19 (EVO) is not just a MK17 with a turret, it's technically pretty different TMO, because they ( MK18 & MK19) don't have the LP Ports in the stage body, so the MK16 was the first SP Diaphragm 1st ( after the MK14 and MK18) which had 2 HF Ports because they placed them directly below the diaphragm ( producing even a 15% higher flow), the same design which was used later for the MK17 and then the MK11.
I have a couple of MK18s, just missing a MK18 UL which I would trade for a rare MK19, which are also nice collector pieces.

 

[lexvil]

The Upgrade Kits are still available, at least in Europe, SP order number here is 10.116.030
The old valve configuration had been notorious for its IP creeping which doesn't mean that you can't use it, but it's recommendable to upgrade.
If I could get the MK18 for a decent price, I would take it anyway, it's a solid piece of engineering and SP History. It was the first diaphragm 1st stage that had a similar air output as the SP Piston 1sts ( 8000l/min) and I wouldn't know another manufacturers 1st which could compete with this number end of the last century ( okay, who needs that much air anyway?).
And sure it is not just a MK16 with a turret as a MK19 (EVO) is not just a MK17 with a turret, it's technically pretty different TMO, because they ( MK18 & MK19) don't have the LP Ports in the stage body, so the MK16 was the first SP Diaphragm 1st ( after the MK14 and MK18) which had 2 HF Ports because they placed them directly below the diaphragm ( producing even a 15% higher flow), the same design which was used later for the MK17 and then the MK11.
I have a couple of MK18s, just missing a MK18 UL which I would trade for a rare MK19, which are also nice collector pieces.

A question you are one of the few that maybe can answer, the MK 16/18 upgrade, are these the same parts as the mk 17 on the HP side and do they use the thicker mk11 diaphragm?

 

[rhwestfall]

now I'm interested....

 

[Kupu]

The 10756045 kit diaphragm is same thickness as MK11 & upgrades the MK16/18 using same HP parts as MK17 .
I assume the 10.116.030 kit mentioned by @axxel57 is the same?

 

[axxel57]

Correct. The 10.756.045 has the thick diaphragm, but I'm sure that the 10.116.030 has the thin diaphragm and the two washer, because it is named here as MK16/18 to MK17/19 HP Tech. Unfortunately I don't have that kit right here in my workshop, but I will check with SP here.
I don't know if it is also in the US available and with the same order number, but I guess so.

 

[axxel57]

Correct. The 10.756.045 has the thick diaphragm, but I'm sure that the 10.116.030 has the thin diaphragm and the two washer, because it is named here as MK16/18 to MK17/19 HP Tech. Unfortunately I don't have that kit right here in my workshop, but I will check with SP here.
I don't know if it is also in the US available and with the same order number, but I guess so.

Just checked with the Technical Department SP here about the 10.116.030 MK16/18 to MK17/19 HP Tech Kit.
They don't include any diaphragm or washers anymore ( the kit includes only the HP Seat, the orifice and the 01.050.317 o-ring), because it seems that for MK16/18 a change of the diaphragm ( and washer) is not considered as necessary ( that's what the Chief Technician told me).
They just want you to change the valve configuration it seems for the MK16/18.
There is no separate Service Kit available, only the 10.756.045 as we know it.

 

[lexvil]

Just checked with the Technical Department SP here about the 10.116.030 MK16/18 to MK17/19 HP Tech Kit.
They don't include any diaphragm or washers anymore ( the kit includes only the HP Seat, the orifice and the 01.050.317 o-ring), because it seems that for MK16/18 a change of the diaphragm ( and washer) is not considered as necessary ( that's what the Chief Technician told me).
They just want you to change the valve configuration it seems for the MK16/18.
There is no separate Service Kit available, only the 10.756.045 as we know it.

That seems unwise since it may encourage someone to reuse the diaphragm unless they also use a mk17 service kit but I guess it makes sense in a strict “upgrade” way. Do they suggest using a MK 17 service kit moving forward?

 

[axxel57]

That seems unwise since it may encourage someone to reuse the diaphragm unless they also use a mk17 service kit but I guess it makes sense in a strict “upgrade” way. Do they suggest using a MK 17 service kit moving forward?

No, you should use for normal service of the MK16/18 the 10.756.045 Upgrade Kit with the thick diaphragm.
It's a bit irritating, because every time you are supposed to buy again the orifice, even when it is not necessary to change it on every service.
The thin membrane had been implemented in the MK17/19, because of the dry chamber.
It seems the designer believed the thicker membrane not to be necessary, and with the MK16/18 membrane you would also not be able to torque the chamber to 30Nm without risking a damage of the membrane and threads.
A bit strange anyway, but the change of the valve configuration is not compulsory.

 

[lexvil]

No, you should use for normal service of the MK16/18 the 10.756.045 Upgrade Kit with the thick diaphragm.
It's a bit irritating, because every time you are supposed to buy again the orifice, even when it is not necessary to change it on every service.
The thin membrane had been implemented in the MK17/19, because of the dry chamber.
It seems the designer believed the thicker membrane not to be necessary, and with the MK16/18 membrane you would also not be able to torque the chamber to 30Nm without risking a damage of the membrane and threads.
A bit strange anyway, but the change of the valve configuration is not compulsory.

Do you happen to know what the fundamental difference is of the main service parts in a MK 11 kit and the MK 16 kit?

I’ve alway thought of the MK 16 as a heavy MK 11.

 

[Kupu]

As DIY, I use MK11 service kits for MK11 and updated MK16/MK18.
The MK11 kit does not have the MK18 swivel orings of course, but otherwise after MK16/18 update the service parts are same between the 3 first stages. Keeping just one kit number on hand makes things simpler and MK11 service kits are not as pricy as MK16/18 updating kit.