LP 10 cylinder leak when disconnected from Hill pump

[seamaster]

My LP10 air cylinder is no longer holding pressure.

I pump LP10 cylinder on Hill pump to green/red line on manometer. Turn air cylinder 1/2 turn, release pressure release valve. Air cylinder pressure leaks to zero with one big puff.

Did that a couple of times. Every time pressure leaks down to zero. I put on the spare cylinder. That one is holding pressure perfectly well, so the leaking problem is not the pump, but the air cylinder.

I shook that not-holding pressure cylinder, and I noticed a clicking sound clear to the manometer end. Something is loose inside the cylinder, and cylinder is not holding pump pressure when disconnected from Hill pump.

Could you guide me on how to open and diagnose this cylinder problem?

[C. Perkins]

seamaster;

With my Hill pump and both cylinders for my LP1 they both will leak the air out if I do not unscrew them real quick for at least one full turnish.
This is the same for screwing them onto the pump. The last full turn until they seat and seal on the fitting.
Never shook a cylinder when it was empty, but may be due to no pressure inside the vessel to keep the valve closed ?
I personally would not attempt to dismantle a cylinder and trust it after putting it back together, but that is just me, too much pressure involved.

Clarence

[RobStubbs]

I always fully unscrew my cylinders whilst under pressure, undoing them partly seems to make the o-rings perish or split (IME). You would obviously need to unscrew them enough to close the valve and I guess 1/2 a turn is not always enough to acheive that.

With regards the rattling cylinder, do not try and open it. You need special tools to start with and then you'd need to replace the internal seal(s) to get it all airtight again. Get it looked at by a Steyr service agent who knows what they are doing.

Rob.

[jipe]

The Steyr male adapter pushes the valve of the cylinder open when the cylinder is screwed on it (other brands like FWB don't do that, it is the reason why FWB deliver a tool to make the cylinder empty while for Steyr cylinders such a tool is not needed, you can make the cylinder empty with the adapter).

So you should not open the release pressure valve of the pump, just unscrew the cylinder from the adapter.

You also should never partly unscrew the cylinder and then screw it again because this destroy the O ring on the adapter (or on the pistol). When you unscrew the cylinder you should always unscrew it completely before screwing it again.

[conradin]

Wow, thanks for all these tips. I have the pump for emergency, but never used it since I have a scuba tank at my home and all the locations that host tournaments that I go to have tanks. Now at least I know what to do in an emergency situation which I have to use the pump.

[seamaster]

i am pretty sure it is not the pump seal, because i don't have the habit of turning cylinder one way then the other way. Turning cylinder is always one way until fully in or fully out.

Seal on pump is intact. My other cylinder is working perfectly well pumped from hand pump. Detached normally, and it holds air perfectly. so i don't think it is a pump seal issue, or my "not to turn one way then the other way" issue. I think it is the cylinder issue.

So no one open up the cylinder to re-seal before?

[jipe]

Turn air cylinder 1/2 turn, release pressure release valve. Air cylinder pressure leaks to zero with one big puff.

Did you try without releasing the pressure release valve ? Just completely unscrew the cylinder when it is full.

So no one open up the cylinder to re-seal before?

No.

[rmca]

Did you try without releasing the pressure release valve ? Just completely unscrew the cylinder when it is full.

I would try this, and then see if the cylinder is leaking... Only after, IF it was, I would put it away and bought a new one.
It's too much pressure to be "playing" with...

My two cents

[seamaster]

Thank you all for the advice of turning cylinder completely off, instead of 1/2 turn, purge release valve, then completely off.

Turning cylinder completely off did show my cylinder was able to hold pressure.

Now, I wonder where did I get that habit of 1/2 turn, then purge the water condensation off pump, then completely cylinder off ? I have been doing that for years. Now I wonder is that a good practice ? I think I got that habit from correspondence with Steyr company advisor years back.

How do you purge water condensation from your hand pump?

Now, even more intriguing to me is why this habit of purging condensation water off hand pump work on one of my cylinder and not on the other?

[rmca]

I do a full turn of the cylinder before opening the release pressure screw. I use the cylinder marks as a reference.

What is probably happening is that half a turn isn't enough to completely close the valve on the cylinder, and when you open the release valve it releases all the pressure from the pump and the cylinder.

Try a full doing a full turn instead.

[jipe]

The advise of opening the purge valve is written in the user manual of some pumps (some Gehmann models for instance) but its is only valid for some cylinders brands and doesn't work with others like Steyr.

There are basically two concept for the cylinder and its adapter:
- the one of Feinwerbau where the adapter doesn't open the valve of the cylinder. It is the higher pressure on the pump side that opens it. With these cylinders/adapters you can use the purge valve.
- the one of Steyr: when the cylinder is fully screwed on the adapter, the adapter push the cylinder valve to maintain it open. So the air can flow in both directions from the pump/scuba bottle to the cylinder but also in the other direction if the pressure in the cylinder is higher than in the pump/scuba bottle (this cannot happen with the FWB cylinder concept). With this kind of cylinder you cannot safely use the purge valve. You can try to carefully slightly open it to get the moisture out but that will also cause a (little) loss of air of the cylinder so that you then need to close the valve and pump again to compensate what was lost by opening the valve.

When I bought my pump years ago, I read the user manual and did what is written, i.e. open the bleed valve to evacuate moisture if any but I have an LP10 and my cylinder lost all it air ! Then I checked what happened and discovered what I wrote above.

[sagara wimaladharma]

dear every one,

This is a simple thing.
you need to replace two O rings in the cylinder.
part number 72.6 and 72.8.
you can do it at home. but you need a special tool for it.
you can get the tool done locally.


Rgds
Sagara

[seamaster]

Just curious.

What tool is needed to unscrew the three-prong hole endcover cap?

Aluminum cylinder is easily marred if wrong tool is used.

What tool are you talking about?

Once you unscrew the cap, then what? I never seen the inner working of the cylinder. What is in there? Can you give a detail description?

[sagara wimaladharma]

Dear every one,

pls give me little time to take some pictures and post.

Rgds
Sagara

[sagara wimaladharma]

Dear Every one,
I took some pictures. I didn’t like to unscrew my cylinder.
I looked for an old one but finally I used mine thinking of helping you all.
but I do not know how to post. I tried my best..
so what shall we do now.
Rgds Sagara

[sagara wimaladharma]

I recvd a massege.. "too big".. I will see what I can do.