Alternative to MDC cylinder valve?

[Geoff555]

Hello, I have a 300bar 7 litre cylinder fitted with a MDC valve about 15 months old. When it was a week old I took it back to the dealer that I purchased from because the knob was loose on the spindle and didnt feel right, it came back with a note stating that there was nothing wrong with it.
On to now, no matter how slowly I crack it open the pressure shoots up and I have to shut the valve off very quickly, then open it to complete the fill. Open as slowly as possible and feel it open and nothing happens then all of a sudden there is a loud click as if something releases and the pressure comes up as if I have turned the tap FULL ON, so far ,apart from once, I have managed to catch it before it has overfilled the rifle.
Getting older and my grip is not so good and I am getting really p*ss*d off taking a chance everytime I fill up.
So the question is, is there a different valve available that will trickle the air in??
Yes I have tried a restricker in the hose but it seems that the restricked flow affects the valve and it locks up, then becoming so hard to turn that it is uncontrolable and snaps open at 'full' pressure.
I really would appreciate your input.
Thank you very much.
Cheers.
Geoff.

[angrybear]

Is the "loud click" from the cylinder valve or from the rifle valve ?

also which gauge are you talking about the pressure shooting up on rifle or cylinder ?

What should happen is you connect the rifle with the whip, slowly crack open the cylinder valve a fraction there will be a quick hiss & the pressure in the whip & cylinder gauge will instantly fly up to equal the pressure remaining in the rifle, then there will be a click & the hiss of pressure entering the rifle & the gauge on both the cylinder & rifle will rise up to the required rifle full pressure, at which point you close the cylinder valve (which was only ever barely cracked open) vent the bleed & disconnect the whip, job done.

If you have grip or strength issues in your hand, it might be that you simply cannot be gentle enough when combined with the amount of effort needed to turn the valve,
it should only need to crack open 1/20th of a turn or so, even filling a buddy bottle mine is never open anywhere near as much as 1/4 of a turn.

It might be worth asking someone else to use the cylinder see if they also have a problem which would show it is a valve fault.

If you're careful you could try using water-pump pliers to give you more torque while reducing the movement ratio.

[Geoff555]

Hello thank you for your reply.
The loud click is from the cylinder valve.
The pressure reading is on the valve gauge.
There is no discernable hiss as such ( my hearing is not that sharp any more) but the pressure does not stop or hezitate at the remaining pressure in the rifle but keeps going UP (fast) and I have to be pretty quick to turn it off before it goes past the 190 bar it is supposed to be. Once I have turned off the air, before the 190 bar is reached, it is then that turning the air back on, to complete the filling, that nothing happens and I can feel the turning effort slacken as if it is opening the valve, open it more (about 1/2" on the circumferance of the rubber knob) and then there is a loud click** from the cylinder valve and it is as if I have suddenly opened the tap suddenly fully.
I have tried to use a large set of pump pliers but it does not make any difference, I have tried to open the valve slowly, indeed very very slowly and nothing happens until there is a sudden release of air. It appears to be uncontrolable and either on or off.

** I can feel the click through the rubber knob spindle on the cylinder valve.

I am sorry but it is difficult to explain as it is the matter of feel.
Re reading your helpful post I note that you say that 1/20 th of a turn, it is not with this one it is more like 1/2" of turn on the circumferance before there is any release of air, that is from it being turned off 'just' enough to stop the air, it is not turned off hard.
Many thanks angrybear.
ATB.
Geoff.

[junglie]

Sounds like the screw that holds the knob on is loose, sometimes hidden under a sticker in the centre of the knob head. I'd try contacting mdc direct if you can't sort it. they're a good company to deal with

[Geoff555]

Hello, junglie well been down that route, there is 10mm. nut exposed , not covered, by anything from new, holding the knob on. The nut is not tightened down fully and allows the rubber knob to slop up and down on the shaft, by approx 1/8". When I took the bottle back after about a week, from new, and it was sent back to MDC and they stated that they (MDC) had stripped and checked the valve and there was Nothing wrong with it!! I had written a note querying the loose nut , it was still loose.
When I said that I could feel the shaft move I meant, that I could feel it move vertically like a small jump, when the valve clicked.
If I tighten the nut down fully to hold the knob then it makes the knob stiff to turn.

Apologies if the information is a bit like pulling it out a bit at a time, I am struggling writing this, being a bit dyslexic.
I heard somewhere that there was a different make of valve that was much more controllable as regards being able to trickle air in, but I can not remember what or where it was.
Thank you.
Geoff.

,

[hmangphilly]

Talk to best fittings
They not too far from you.

Maybe a bigger or tee bar type handle on the valve would give you better control .

It's possible that you might be closing the valve too tightly.
I did that and stripped the square hole in the knob .
New knob from dive shop easy fix

[Geoff555]

Hello I have used pump pliers a foot long and can open the valve IN TINY amounts so I think that I can safely say that the amount of opening and the speed is not the problem. I have stated that I only turn the valve off just enough to shut the valve off!!
Please note that I have already stated that the knob retaining nut is not tightened down and the knob is loose, this has been checked by MDE as being correct and the valve sent back to me.
I did try nipping up the nut to take the slop out but this makes the knob very hard to turn!!

I no longer trust MDE as to be honest I think they are trying to fob me off with a defective unit, I will not buy a MDE valve Hence the ORIGINAL QUESTION, does anyone know of an ALTERNATIVE VALVR to the MDE.

Cheers.
Geoff.

[hmangphilly]

Hello I have used pump pliers a foot long and can open the valve IN TINY amounts so I think that I can safely say that the amount of opening and the speed is not the problem. I have stated that I only turn the valve off just enough to shut the valve off!!
Please note that I have already stated that the knob retaining nut is not tightened down and the knob is loose, this has been checked by MDE as being correct and the valve sent back to me.
I did try nipping up the nut to take the slop out but this makes the knob very hard to turn!!

I no longer trust MDE as to be honest I think they are trying to fob me off with a defective unit, I will not buy a MDE valve Hence the ORIGINAL QUESTION, does anyone know of an ALTERNATIVE VALVR to the MDE.

Cheers.
Geoff.

Well pardon me

[Rickenbacker]

Hiya Geoff,

I would talk to best fittings. I've found them an excellent firm to deal with.

Regardless of folks on here saying it's 'user error' - There are / have been difficulties with modern MDE valves being fierce for the purpose of filling guns.

I have a very fierce MDE valve on one of my cylinders, and it's a PITA to use. I imagine it's an un-restricted one.

This post from somebody who knows:

Year's ago MDE used to use machined acetal as the threaded seat in all diving valves these you could open slowly and regulate the flow without a restrictor but now they use a moulded nylon seat that has a habit of gripping the raised sealing ridge in the valve , So now the valve feels as tight as buggery and then suddenly lets go of the seal ridge causing you to suddenly open to a very fast flow.

I worked at MDE for 13 years.

Hence MDE have tried various spec' flow restrictors in their gun charging valves over recent years. Apparently at one time they were reportedly too slow, taking too long to fill guns. It seems this is the latest version, as sold by best fittings, here: http://www.bestfittings.co.uk/shopexd.asp?id=285

I understand why you wouldn't want another valve from MDE, Geoff. Which is why I'd be asking best fitting for advice / any alternatives...


ATB - Phil

[Geoff555]

Thanks to all for the input, I think Phil that you have hit it on the head, it does feel like something has suddenly 'let go' and the pressure is suddenly released. I have struggled for over a year and tried everything I can think of.
Having sent it back and having been told that there is nothing wrong then it makes me wonder about there quality control and wether indeed if the person that tested it actually understood what happens when there is a sudden release of air IN AN AIR RIFLE.
Sorry if I was a bit sharp hmangphilly, fed up with constantly fighting the problem and getting nowhere.
ATB.
Geoff.

[angrybear]

Having read all your replies Geoff, it sounds to me that the valve is faulty, there should not be any play in the fit of the valve handle for a start, and there should definitely not be any "click that you can feel" from inside the valve that shows something is loose inside which is never a good sign.
You should have a brass shaft with a nice fine thread on it to give a very smooth operation.

The controllable valve that trickles air is the MDE jubilee valve, it sounds like yours is unfortunately a duff example.

I'd write a letter to the Boss at mde complaining about both the valve & the service & ask for the valve to be replaced.

[Geoff555]

Hello, thank you angrybear, to be honest I have my suspicions that not a lot was done, the shop that supplied the bottle was not keen to send it back to MDE , this time I will send it to them with a letter to the boss.
I will have a chat with Best fittings as well.
All the very best to you all.
Cheers.
Geoff.

[angrybear]

Initially I'd just write to their boss, shipping cylinders (legally) is difficult & expensive as not many people knowingly carry them, It might end up cheaper to take it up to them in the car.

[emin-j]

Sounds to me like the valve is sticking and suddenly ' letting go ' when the valve is unscrewed to a high flow rate level, I have the mde valve on my bottle and don't consider it a quality item, I open the valve slowly then there is a point where the air will barely start to flow then without unscrewing anymore the airflow will suddenly increase to the point the valve in the gun will 'click', at that point I have to turn the air pressure valve down to restrict the airflow I can then adjust the gauge to give a slow fill.
It reads worse than it actually is, I've got used to the method now.

[Geoff555]

Thank you, I was going to send just the valve only but upon considering then it would be better to write and see what happens and if necessary drive there. Good idea angrybear,ta.
Upwards and onwards.
Cheers.
Geoff.