Tank valve cleaning

[fengz]

After about a hundred dives or so, my tank valves were getting harder to turn, which made valve drill difficult. When I took one apart, I found quite a bit of gunk built up between the bonnet nut and the stem. My question, how and how often do you clean your valves, and do you replace all parts listed in the manual, in particular, the plug-seat assembly, and the bonnet gasket, every time? I found a cheap source for those parts on Aliexpress, but I still don't want to waste perfectly good parts.

feng

 

[NAM001]

There is not much to rebuilding valves, just do the whole thing. An ultrasonic sink or cleaner is a big help for cleaning.

 

[bl6394]

Copper crush gaskets are supposed to be one time use items. Sure - I've seen some people reuse them. I've also seen some people don't bother with torque values when assembling components either.

I'd suggest a bit of training. The PSI Valve Repair Technician class would cover this subject well. You might also add on O2 Cylinder cleaning while you're at it.

 

[akdeepdiver]

I break down, 02 Clean, and rebuild my valves annually. Doesn't take to long and its easy to do.

 

[fengz]

Copper crush gaskets are supposed to be one time use items. Sure - I've seen some people reuse them. I've also seen some people don't bother with torque values when assembling components either.

I'd suggest a bit of training. The PSI Valve Repair Technician class would cover this subject well. You might also add on O2 Cylinder cleaning while you're at it.

How about the plug & seat assembly, do you toss that as well? The valve service manual only says replace it every five years.

I will look into the PSI Valve Repair Technician class.

Thanks.

 

[Peter69_56]

Are you using the cylinder for Nx or just air. You need to consider which kit if used for high oxygen levels?

 

[kwinter]

I'll clean them up as needed annually or if they start to get difficult. A full rebuild with all new parts every 5 years when the tank goes for hydro.


iPhone. iTypo. iApologize.

 

[bl6394]

How about the plug & seat assembly, do you toss that as well? The valve service manual only says replace it every five years.

I will look into the PSI Valve Repair Technician class.

Thanks.

For valves I'm O2 cleaning (which is most of them) - I'll refresh the teflon bushing, and orings and examine the seat. For the $7 part - I'll usually replace the seat unless it looks really good. I'll also replace the burst disks annually - cave fills.

Bjorn

 

[fengz]

I don't need to O2 clean it, as our LDS offers banked nitrox. The valves will not see anything higher than 32%.

---------- Post added April 28th, 2015 at 11:34 AM ----------

I'll clean them up as needed annually or if they start to get difficult. A full rebuild with all new parts every 5 years when the tank goes for hydro.


iPhone. iTypo. iApologize.

For valves I'm O2 cleaning (which is most of them) - I'll refresh the teflon bushing, and orings and examine the seat. For the $7 part - I'll usually replace the seat unless it looks really good. I'll also replace the burst disks annually - cave fills.

Bjorn

What do you do differently between cleaning the valves and rebuilding them, other than the burst disk part?

 

[bl6394]

What do you do differently between cleaning the valves and rebuilding them, other than the burst disk part?

For me - there is no difference. Almost any of my cylinders may be used for partial pressure blending (except for the argon bottles) - hence the annual O2 cleaning. O2 cleaning requires a complete dis-assembly. After dis-assembly - O2 cleaning involves a coarse cleaning of parts, a ultrasonic bath. Thorough rinsing. Test of rinse water. Final inspection.

If I'm going through the trouble to do an O2 cleaning - I'll refresh any parts that are marginal - certainly the cylinder oring and teflon bushing. Possibly the valve seat. I also like to replace the burst disks annually on my LP Steel cylinders - as they are frequently cave filled. (Whatever that means...)

On a rare occasion - I might rebuild the valve on a shop cylinder in service for air only (e.g. not Nitrox). In that case - I would just replace the required parts. That would involve the copper crush washer and any parts that are damaged - which would usually include the teflon bushing, valve stem oring, and the seat. Some OW students like to use gorilla strength when opening and closing their valves...