High pressure port blocked...anyone seen this before?

[IceCreamPirate]

I'm having a problem with my regulator and looking for some possible explanations...

Last week I was out working on a project involving several shallow dives. On the first dive my gear functioned totally normally. I switched it over to another tank on the boat and got back in the water to hang out on the tag line for my surface interval (sea sick...). The guys on the boat offered to pass me my gear down so I wouldn't have to get back on board. I asked them to turn my air on, but when they did my analogue gauge stayed stuck at zero (100% sure that the tank was full). Because we were pressed for time, they passed me the stand-by diver's gear instead and I used her kit for the next two dives. I (and everyone else who was there) figured that the problem was with my gauge, so that evening I borrowed a friends console and hose and switched out my hose for hers. When I set up my gear the next day I thought the problem had been solved, as her spg functioned like normal. But...when I switched tanks after the first dive and turned the air on, the gauge stayed stuck at zero again! This time I noticed that the hose didn't pressurize at all...no movement, no tension. I borrowed gear to finish the day.

So. Two days ago I took my reg to the nearest shop, where I had gotten my gear serviced in January '14. The tech there said he had never seen this exact problem before. I asked if he thought he would be able to fix it. He wasn't sure. I asked if he thought it would be okay (safe) if I tried moving the hose to the other high pressure port and he said yes. BUT yesterday I asked a very experienced and knowledgeable mentor what she thought, and while she had never seen this problem before either, she thought that moving the hose to a different port was a bad plan, because if something is inside the first stage blocking air flow...it needs to come out. It is a Sherwood regulator and few shops in my area deal them, so my game plan is to make the trip to the nearest dealer sometime next week. I know pathetically little about how my gear works. While I am trying to learn as much as possible, it would be super helpful if anybody out there has some insight! It is a diaphragm first stage, if that helps at all.

 

[Wookie]

There is a teeny tiny very small orifice in the inlet of the hose. I can see that it might become plugged and fail to allow pressure in the hose. This is an indicator of a larger problem, however, in that something got into your regulator and plugged said orifice. If my gear were exhibiting that kind of behavior, I'd take the following steps:

1. Pull the HP hose off and look at it.
2. Pressurize the reg with no hose on it and make sure air comes out of the port.
3. Look at the inlet filter and check the color. Green is not the right color.
4. move the hose to another port and try again. I don';t remember any of my sherwoods having 2 HP ports, but I haven't owned a Sherwood in many years.
5. I'd take it to a tech and have it fixed before I dived it again.

 

[redacted]

The symptoms you describe (it was a good description) make it fairly clear that you have some foreign matter loose inside the HP chamber of your 1st stage. It should not be a big job removing it BUT, I would be a bit concerned about where it came from. The filter should keep such objects out. I could have been something missed in a service, or it could be a piece from a damaged o-ring or seat. It really needs to be fixed before the problem grows into something more that no reading on the SPG.

 

[Colliam7]

It is an uncommon problem. And, I don't think we can offer a certain diagnosis from afar, at least not without more information. If I understand your comments correctly, the presenting problem could be either with the hose or with the first stage. But, the CAUSE of the presenting problem may be another matter entirely. Frank is correct - the orifice in the inlet on the HP hose is VERY small. Frankly, the orifice in the HP port on the first stage is also small, albeit a bit bigger. Your description of what happened is compatible with either / both an obstruction in the HP hose inlet orifice, or an obstruction in the first stage HP port orifice. It is also compatible with no air getting into the first stage from the cylinder.

I am not sure if the tech made his comments before or after actually looking at the first stage - if he simply took it in and was appropriately non-committal about whether it could be fixed (not yet knowing what the problem was), the comment makes sense. But, the solution is reasonably pretty straightforward, and can be approached in a tiered manner. And, you could probably do part of the diagnostic work yourself, as a learning experience.

Two questions: a) when the SPG failed to register any pressure (either time), did you try to breath from a second stage? I am going to presume that the problem is in either the HP chamber / HP port orifice, or the hose, in which case you would be able to breath from a second stage. However, if your were getting NO air into the first stage, then the filter is definitely a suspect. But, since you mention that the reg actually worked (for a while) after you changed the SPG, the filter moves to a lower place on the list of possible causes; b) as I understand your comments, when you borrowed a friend's console, you switched hoses, so that on both days you used the same hose (yours). Is that correct? If you did NOT switch hoses, and the problem recurred, then the hose becomes an unlikely culprit (and items 2 and 3 in my list, below, become extraneous).

If it happened to my gear, I would want to fix the problem, AND I would want to know what the caused the problem in the first place. I would:

1. Change the SPG hose to the other HP port. If that works, the problem is more likely to be with the HP port on the first stage (rather than the hose), and that would suggest that routine servicing of the first stage is in order. If it doesn't work, you still can't be sure if the problem is with the hose, or that both HP ports are obstructed.

2. If changing ports didn't work, remove the HP hose from the first stage. Remove the SPG from the other end. Blow LP air through the hose, from the SPG end (not the inlet end). If something has gotten lodged in the inlet orifice of the HP hose, it probably came from the first stage or the port space, and retrograde air pressure may loosen it. However, if that (retrograde air) works, then routine servicing of the first stage is still in order, because the obstruction, whatever it is, probably came from the first stage (unless you have recently removed the HP hose from the first stage, and some particulate matter got in the space before you put the hose back on).

3. Change out the HP hose. Retrograde air may not be sufficient to remove the particulate obstruction. If that works, you know the problem was with the hose, but you still don't know if the originating problem was in the first stage.

4. If manipulating the hoses doesn't solve the problem, have the first stage serviced - mainly have it disassembled, carefully inspected, and cleaned. During the disassembly, I would specifically look for particulate matter (e.g. very small pieces of black rubber that might come from a brittle O-ring, or very small metal shavings that might come from mis-threading of the HP hose, or even the other HP port plug during re-assembly) in the HP chamber. You might not find any, but I would put on my magnifying goggles and look. While I do not wish to indict the service that was done in January, awap makes a good point - it is possible that was some debris was missed during the servicing, or even introduced into the HP chamber at the time of servicing.

Now, some might say to skip all the diagnostics and go straight to step 4, first stage servicing, because that is where several of the steps, above, end up. And, that is not unreasonable, and servicing probably should be done anyway. But, if you simply have the first stage serviced, after which everything works, you may not have learned much about why the problem occurred in the first place.

 

[IceCreamPirate]

Thank you very much, Colliam7, for your detailed reply! I was bit unclear in my original post: I used my friend's console AND her hose the second day, so the problem shouldn't be in the hose. The strange thing is that even after I switched hoses, the spg functioned normally on the first dive but failed to pressurize before the second dive. So whatever is in there obstructing the air flow must be moving around at least a little bit. I did not think to try breathing from a second stage at the point, but I had been breathing from a second stage during the previous dive (obviously) so I'm confident that the first stage was getting air at least until the point when I changed tanks. I did switch the hose to a different HP port and it functioned, but I did not try to dive on it and I won't, based on everybody's feedback. I am going to have it serviced by a different shop (not the one that serviced it in January). I appreciate the responses because I think I will have a better idea of what I need the technician to look for, plus some possible causes of the issue.

 

[yucascuba]

IceCreamPirate, how did you solve your problem? I'm having the same situation with my first stage, which is already in the tech shop. The weird thing is that the filter is clean, but when I unscrew the HP hose there was a green thing around the threads

 

[bl6394]

Assuming your HP port is blocked. In a pinch - consider removing the hp hose. Applying a bit of water to the port, and chase the water through with a port plug - turning briskly. The hydrostatic force created will expel whatever is lodged in the HP port orifice. Reattach to a high pressure source, purge the regulator and hopefully - the obstruction has been removed along with a few drops of water.

And better yet, strongly consider getting that reg serviced...

Bjorn