Scubapro O-ring Sizes

[Couv]

As a matter of fact, I was hoping to go to a fastener store tomorrow (was going today, but had to pick up the wife from work and I ran short on time) to stock up on nylock nuts, 4-40 screws etc. Is the washer metal? I would think so.

c

 

[halocline]

Damn, I was really hopeful about those HP seats. There's a certain SP dealer whose stock of leftover seats (when they rebuild a MK5/10, they keep the two seats they don't use) I might be able to raid. I have several (10 at least) of the tall seats that lower IP, but my IP tends to be in the 125 range with the shortest seat and one or none of the washers.

Regarding sanding the bottom of the seats to lower the tall ones, there might be a problem with that; it would increase the space that the HP seat o-ring has to fill to seal. I think you'd have to lower the conical seating area, which could be done with the right router or drill bit. In fact, that way you could conceivably make your own conical HP seats.

 

[redacted]

As a matter of fact, I was hoping to go to a fastener store tomorrow (was going today, but had to pick up the wife from work and I ran short on time) to stock up on nylock nuts, 4-40 screws etc. Is the washer metal? I would think so.

c

Yes, it is metal. Looks like polished stainless steel. 10.5mm OD, 6.0mm ID. and 2.5mm deep. Bevel on the outside shoulders. If you have to error, 0.1 or 0.2mm extra on the thickness will just compress the o=ring a bit more.

 

[HenrikBP]

I got home earlier than expected tonight ...

I get very similar numbers for that spacer:

O.D.: 10.7 mm or 0.424"
I.D.: 6.4 mm or 0.254"
Thickness: 2.5 mm or 0.099"

Henrik

 

[BlueWaterDiving]

Damn, I was really hopeful about those HP seats. There's a certain SP dealer whose stock of leftover seats (when they rebuild a MK5/10, they keep the two seats they don't use) I might be able to raid. I have several (10 at least) of the tall seats that lower IP, but my IP tends to be in the 125 range with the shortest seat and one or none of the washers.

Regarding sanding the bottom of the seats to lower the tall ones, there might be a problem with that; it would increase the space that the HP seat o-ring has to fill to seal. I think you'd have to lower the conical seating area, which could be done with the right router or drill bit. In fact, that way you could conceivably make your own conical HP seats.

Do you need some seats??? which ones do you need???

 

[halocline]

Do you need some seats??? which ones do you need???

Yes, I always need extras of the "+" seats that are the shortest ones in the kit, the ones that raise the IP. I could also use a couple of the middle size, they're marked -I. If you have some extras you'd be willing to send my way, please let me know what you'd like for them. Thanks for the offer!!

I just checked my stash and I have four of the + seats and four of the -II, none of the -I. I also could use D400 seats, but those are really hard to find separately from the kit. Those last a long time anyway.

 

[BlueWaterDiving]

Ok here are what the seat are for (-l) saet is to raise the Ip about 5 to 7 psi, and the (X) is a standard seat that should be used with 2 shims. And the (ll-) is to lower the IP. I hope this helps

 

[halocline]

My MK5/10 seats, in fact all the ones that I have ever seen, are marked as follows:
+ shortest seat, will result in higher IP
-l middle height, will result in slightly lower IP
-ll tallest, will result in lowest IP

I suppose the "X" could be confused with a "+" but it is the shortest of the seats, not the middle height as you seem to be saying. The shorter the seat, the higher the IP.

Can you check the height on your three types of seats again?

Thanks

edit: I just checked a new, unopened MK5 kit, and sure enough, the + seat is the shortest, followed by the -l, and the -ll is the tallest. This means the + raises the IP as I said, not the -l.

BTW, I don't believe the repair guide says anywhere that two shims should be used; it just says that a maximum of three can be used to raise the IP if necessary. Feel free to correct me if I'm wrong.

 

[BlueWaterDiving]

My MK5/10 seats, in fact all the ones that I have ever seen, are marked as follows:
+ shortest seat, will result in higher IP
-l middle height, will result in slightly lower IP
-ll tallest, will result in lowest IP

I suppose the "X" could be confused with a "+" but it is the shortest of the seats, not the middle height as you seem to be saying. The shorter the seat, the higher the IP.

Can you check the height on your three types of seats again?

Thanks

Read what I put. ScubaPro says to use 2 shims all the time and adjust from there as I said this is right out of the good book. Maybe somebody can explain it better

 

[halocline]

Read what I put. ScubaPro says to use 2 shims all the time and adjust from there as I said this is right out of the good book. Maybe somebody can explain it better

I did read what you said. First, you're wrong about the seat size, check again. Second, please post directly from the manual where it says to use two shims.