Alkin...Anyone else confused?

Jump to latest Follow Reply
Keith2324

Keith2324

Member
Apr 1, 2015
503
50
FL, United States
Am I the only one confused by Alkins' latest videos? Initially it was stated when filling a tank to never create a back-pressure on the valve since it may damage the o-rings. Now with the latest videos they are showing the exact opposite. You can open the lever and the tank valve and then turn on the compressor.

I for one will not be doing it this way. But I was just wondering if some of you also found this odd.



Keith.
 
Not sure exactly of the vid or procedures/recommendations or "valve" you speak of, or who did the recommendations...

A lot of hype old wifes tales on specific starting/stopping procedures, some true some not. Most left over from delicate fragile small momentary type compressors that really have no basis in a heavy commercial duty HPA compressor's functions like the Alkin or Bauer. Starting with head pressure is no problem at all, nada.

Many big dive shops have auto start/stop set to come on at 225bar and shut down at 300bar. Filling a cascade bank of large tanks, doing this all day long.Constantly starting stopping as dive tanks get filled from the reservoir bank of large tanks.

The thing I'd avoid is using a microbore discharge line with slow fill restrictor, that will put a continuous heavy unnecessary load on your compressor, and give false gun/tank autostop fill pressures. Also, trying to start compressor while pumping into a dead end closed discharge line probably not a great idea...



From the Alkin manual...

"Cylinder Filling Operation

1. WARNING:Never open the filling valve unless a bottle is connected and its valve is open. Otherwise hose whipping may cause serious injury. 2. Connect the yoke to the bottle. Open the valve of the bottle. Open the filling valve. 3. Run the compressor; on systems with automatic stop pressure switch, the compressor will stop at the preset pressure. When stops, shut the valve of the bottle; remove the yoke.

Pressure Swtichgage

The W31 series compressors are controlled by a pressure switch that cuts off the motor control line when the operating set pressure is reached; it cuts in when the pressure drops below the pre set low pressure limit, starting the motor again. When the main motor is stopped by the pressure switch, the two top fans keep working for an additional period of time (generally 4 to 10 minutes depending on the ambient temperatures); this is controlled by a timer (0-30 minsetting range) . This feature is incorporated in the system to permit good cooling even after the compressor stops, thus allowing the next start in a cooler state. This improves the valve life and the performance, it protects the lubricant and prolongs the overall life of the compressor."

jmo
 
Upvote 0
I don't know anything about the model. I always open the tank valve before filling. This is because I use a check valve between the tank and the compressor (AV-4500). When the compressor reaches the tank's pressure, the check valve opens up to allow more air into the tank. There is no back pressure to the compressor using a check valve inline.
 
Upvote 0
Full disclosure: I didn't watch the video. However, just looking at the intro photo, it looks like a tank is being prepared for breathing air. In that case it's quite likely that you're starting from an empty tank and doing a full fill. It's only we airgun types that sip off the top 5% and then fill again...

The manual that came with my Alkin says not to open the valve to the tank before pressure is applied in the line.

GsT
 
Upvote 0
1:10 mark in this video











https://www.youtube.com/watch?v=gVj-2P-kM6U















2:50 in the second video











https://www.youtube.com/watch?v=g3xNHsip2bQ









Click to expand...


Thanks for posting those vids, I understand what you're saying now...

IMO the first vid is trying to show us how the auto bleeder fill valve works, from someone thats first language is not English. And it kind of loses something. But ya, total 180°contradiction from the first vid to the second, unless you read between 'his' lines and see what he is actually showing us, that he is manipulating pressure points, to point out the functions of this bleeder fill and its possible bleeder oring damage if you don't completely shut the tank off before taking off the fill, like he states in the vid... Thats my take on it anyhow, as the 1st video is even titled "ALKIN FILLER VALVE"

The second vid shows an acceptably normal way to fill a tank, and it is exactly like the Alkin manual I c&p above....

Not saying that guy isn't very knowledgeable about the Alkin, he seems to be, but his narration misses the mark on precise explanations of what he is really trying to show us in his titled "ALKIN FILLER VALVE" vid...

I'd most diffidently go by his second vid and the W31 manual for normal tank filling...

Again, copied right from page 7 in the W31 manual" and exactly as in his 2nd vid.

https://www.scubaengineer.com/pictures/compressors/alkin/W31_Inst_Manual.pdf

" 2. Connect the yoke to the bottle. Open the valve of the bottle. Open the filling valve. 3. Run the compressor "

Auto start/stop functions prove starting with fill whip pressure is normal operation.

But ya, unless you watch/understand the 1st vid carefully, seems like a direct contradiction to the 2nd vid for sure...

jmo
 
Upvote 0
I would think it “best” to not open the tank valve until the compressor has run a minute or two and the internal system is pressurized . Would it hurt the unit start it under pressure ? Don’t know but would you start your car with the gas pedal to the floor? No you give it at least some time to get the oil pressure up . Just respect for the equipment. And frankly what is the advantage to do it the wrong way 
 
Upvote 0
From watching the video. The way I comprehend is this. He is opening the two drain valves on the water separator to insure the compressor is not starting under a load. I also believe he is stopping the compressor in this order for multiple bottle filling. Which will not apply to me as I only fill one bottle. Notice as he opens the two valves on the separator before the pressure was bleed. Since that didn't bleed the air from the gauges it tells me there is a one way valve in play. At work we have a 4 stage compressor that supplies a tank that is 12' x 2' and there is a one way valve between the bottle and priority valve. In the air gun world its called a PMV. 

thats how I see the video, I have been wrong before. Here is how I fill.





56292D4D-3630-43B2-AAFE-EDCE0F4B6307.1621089133.jpeg
 


 
Upvote 0
All I am saying is in one video he is stating you should never open the valve on the bottle and put air into the fill whip as the "back-pressure" may cause damage to the o-rings in the fill assembly. In the other video, he is doing the complete opposite.

I wait for the pressure to build in my fill whip before I open the valve and then the bottle. That's the only difference I was trying to point out.
 
Upvote 0
I was always under the belief that with the compressor turned on, one or two bleed screws are open to let the compressor get nice and ready and not start off on a load. I usually count to 10 and shut off the bleed valves.



then I let the compressor build pressure till it’s pressure is equal to the pressure in my SCBA tank, and then and only then do I open up the valve knob on the SCBA. 

One at 4500 psi, I shut the knob valve on the SCBA and upon a half turn from full close, I’ll quickly open up a bleed valve so when I turn the compressor off there is no back pressure, as air within the compressor is already venting out.

From there I open up the remaining bleed valves quick like. My Alkin W31 has three areas for air bleed- at the bottom of the water filter separator, at the oil n water separator, and finally one at the end of my fill whip, close to where it connects to my SCBA tanks.



So, has the method changed in start up and shut down, or has a better method been developed to aid in compressor life that I’m hearing?
 
Upvote 0

So, has the method changed in start up and shut down, or has a better method been developed to aid in compressor life that I’m hearing?
Click to expand...

That's the part I'm trying to figure out. But I like the first way of doing it better. It just makes more sense to me. Maybe an Alkin rep will chime in and let us know if there is a big difference between the two methods. I just don't want to damage my fill adapter/valve. 

Keith.
 
Upvote 0
I will continue by starting up with bleeders open. That is a no load condition and that can not be improved upon. And I like letting the pressure build to bottle pressure before opening the bottle letting air flow. I think filtration will be best with that method. 

I don't like when I am too slow shutting the valves and turning compressor off. When I am to slow the pressure climbs so fast the relief valve opens. That won't hurt anything but. In my past leaks in the pressure relief happens more than any other leak in the 4 stage compressors I have maintained. I appreciate the updated video. If you all hear anything that I need to change I am all ears.
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu