Scubapro MK18UL Servicing Question

[mahjong]

Hi.

I finally want to take my brand new MK18UL to the shop for servicing or general check-up before diving it--it's never been wet (should a brand new reg be serviced, or checked out in some limited way?). I recall reading about some problematic tendencies with the MK18--perhaps HP seat free flow? Is there something I should alert the technician to be careful about, just in case he might never have seen an MK18UL?

Thanks,

Mahjong

 

[Packhorse]

Buy a IP guage and check the IP yourself. Cheaper than an unneeded service and a great tool for monitoring the state of your reg.

If you need to inform the tech to be carefull then you have probably chosen the wrong tech to service your gear. (IMHO)

 

[mahjong]

Thanks for the reply.

I have thought about getting an IP gauge and might do so soon.

In an ideal world, you are absolutely correct regarding the technician. I have, however, met too many wobbly technicians to have too much faith in them. Even very good ones, I have found, can stop paying close attention at times. I am in Hong Kong and I am not sure if my technician will have ever encountered an MK18UL before. If so, he will be working on a combination of experience with similar (but not identical) regs and some theory. And even if he might have encountered an MK18, perhaps there is something about servicing the UL that might require special attention--e.g., a special part or something. I thought if I could give him a heads up I might be helping him out and putting my mind at ease. As for the reg even needing a servicing, given that it's new--it's new old stock, so this reg has been sitting around for a few years, I believe. Perhaps this doesn't matter, but I was going to ask the technician about this.

Many thanks again.

Mahjong

Buy a IP guage and check the IP yourself. Cheaper than an unneeded service and a great tool for monitoring the state of your reg.

If you need to inform the tech to be carefull then you have probably chosen the wrong tech to service your gear. (IMHO)

 

[kgault]

The ML18UL is a very sensitive creature. I have one and I am a SCUBAPRO trained technician. The seat in this regulator is very brittle, and tends to be the reason for it needing service. When I used the MK18UL as my primary regulator I was overhauling it every 6 months (150 dives + pool) as it would start to leak past the HP seat. The Mk16 and the MK18 both originally shared the same seat, but can now be upgraded to the knife edge and seat from the Mk11/Mk17 to improve their performance (and increase their required service interval; the seat is replaced by a knife edge and the new poppet has a HP seat at the end). Unfortunately with the metal in the MK18UL body the upgrade is not authorized by SP as putting the MK17 knife edge in place of the MK18UL seat causes dissimilar metal concerns.

A concern for overhauling a UL regulator is that the anodized aluminum coating can be easily damaged with tools, and the regulator will dissolve (close approximation) in salt water or vinegar solution through exposed areas like gouges. The UL regulators are not meant to be put in the same solutions in the ultrasonic cleaners, and SP suggests cleaning them with soapy water. I have been using diluted Blue Gold as the harshest cleaner I will use on an UL (MK18 or MK20), and for very short durations in an ultrasonic cleaner after scrubbing with a tooth brush.

The ultralights are great travel regulators especially when you are trying to deal with the new airline weight restrictions.

Keith

Thanks for the reply.

I have thought about getting an IP gauge and might do so soon.

In an ideal world, you are absolutely correct regarding the technician. I have, however, met too many wobbly technicians to have too much faith in them. Even very good ones, I have found, can stop paying close attention at times. I am in Hong Kong and I am not sure if my technician will have ever encountered an MK18UL before. If so, he will be working on a combination of experience with similar (but not identical) regs and some theory. And even if he might have encountered an MK18, perhaps there is something about servicing the UL that might require special attention--e.g., a special part or something. I thought if I could give him a heads up I might be helping him out and putting my mind at ease. As for the reg even needing a servicing, given that it's new--it's new old stock, so this reg has been sitting around for a few years, I believe. Perhaps this doesn't matter, but I was going to ask the technician about this.

Many thanks again.

Mahjong

 

[Couv]

Hi.

I finally want to take my brand new MK18UL to the shop for servicing or general check-up before diving it--it's never been wet (should a brand new reg be serviced, or checked out in some limited way?). I recall reading about some problematic tendencies with the MK18--perhaps HP seat free flow? Is there something I should alert the technician to be careful about, just in case he might never have seen an MK18UL?

Thanks,

Mahjong

Hell Mahjong,

If it is brand new, it probably does not need servicing, but here is my standard cut and paste to help you make that determination for yourself:

Regulator inspection:

There are a few checks that everyone is capable of doing. One is the intermediate pressure check. Get a simple 300 psi pressure gage from Ace Hardware (I like the helpful hardware man better that the giant store types) and adapt it to your quick disconnect
SCUBA Hoses and Adapters..Variety of Lengths, Colors, Fittings
or get a pre made one : Intermediate Pressure Gauge Plugs Into The BCD Quick Disconnect Hose from LeisurePro.com

Find out the what the IP range should be for your regulator (most are ~ 135 +/- 10 psi .)

The intermediate pressure should remain steady after stabilizing within the acceptable range. If it tends to climb (creep) that indicates there is a problem with the first stage that must be corrected.

Another check is the cracking pressure of each second stage. Partially fill your kitchen sink and immerse the regulator with the mouth piece up. Air should begin to flow before the diaphragm gets more than a 1 1/2 of inches deep. You may have to put plastic tubing in place of the mouth
piece to do this, but usually not. If you want to get fancy (there is no reason to get fancy) make a simple manometer from plastic tubing and a yard stick * » * » Manometer
and you can check the cracking pressure with a good deal of accuracy. If you want to get REAL fancy, buy a Magnehelic gage from eBay, but again no reason to do that.

Next, a water tight check is also very easy to perform and checks the integrity of the second stage housing. Hook
the first stage up to a tank and without turning on the air (or if you have a good tight dust cap you can use that instead) draw a breath on the second stage until you hear the diaphragm retract. Do not draw too hard as it will collapse the exhaust valves and cause a leak. Does the regulator hold
vacuum? If so, it is probably water tight.

These simple checks can be done by anyone. They should be done often, not to mention when new out of the box or after shop service.

Check early, check often.

couv