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look what I found lurking in my 3rd stage head (MCH5)

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  • trdscfjc
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    going to bring this to a close, will continue in the summary thread

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  • karl
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    Congrats on wrapping up your compressor rebuild project.
    It would be great if you could take all the key pieces of information you learned along the way and condense it to one post the moderators might consider making a "sticky note" or whatever the first visible threads are called.
    I am curious what your interstage pressures are and what your blowby rates are at 100 psi, 600 psi and 3000 psi (or whatever the normal operating range is for each stage).
    It would also be really helpful to put the aftermarked part numbers for the bearings and any other consumables you located along the way

    Thanks,
    Karl

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  • trdscfjc
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    Originally posted by flatracker View Post
    glad to see you got it worked out and pumping properly. it has obviously been a long journey.
    yes it has...tyvm

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  • flatracker
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    glad to see you got it worked out and pumping properly. it has obviously been a long journey.

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  • trdscfjc
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    just got back from Nuvair, 230 miles (round trip)....I was told over the phone to not drill/tap the new red head so I loaded up the compressor in my truck and drove it to Nuvair so they could get a first hand look at what I was dealing with, they said they could fit the new head and do the necessary modifications for 190$, went for a long lunch and came back to a freshly installed red head mch5.

    Pumping efficiency is much better I am now getting 3.25 CFM @ 1500 PSI, 2.75-3.0 CFM @ 3500 psi, so the saga is over it seems....im not sure if it was the cylinder or the valve or the rings in the old style head/piston assembly but the newly designed valve/piston/head configuration seems to be the winner... I will update on how things look down the road, but for a 3500 HR. machine im very pleased with this output
    Last edited by trdscfjc; 08-03-2015, 11:27 PM.

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  • trdscfjc
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    called nuvair, the fittings that came with the new head are for the new style mch5`s, my machine is an older model and the new fittings will not work with the old style intercooler tubes, mitch@nuvair has been very helpful in getting this sorted and has come up with some options for me to get this new head working on my machine....fittings should be shipping first part of next week

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  • BritCNGUser
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    I will do a test with a large lump of standard plastic pipe hooked up for 5 mins rather than mess with copper etc to find no real gain. Has to be the way to go.
    Agreed a regulator is not really a safety device, however that was not quite the point, because , well .... run with me. Gas regs here are tight, and whilst there is no laws saying we can't do any of this, this is not because they like it but because no one else in a domestic situation is doing it! In most parts of Europe yes, but here? No. As soon as I talk to anyone vaguely connected to the gas supply industry about this, you'll hear them having a conniption, followed by brain-seizure. More because of the "Not born here" mindset than any rational thinking, but that is how it is. The argument is lost before I start. So in this context a 'regulator' is a safety-device, and if it came to it, around the real layman, I would lose any argument to the contrary. Now, those of you on this forum understand what is actually happening here, but unfortunately it is not the likes of you I would be reasoning with. If only.... In a shoot-out with a bureaucrat, the paperwork always wins.
    1. I am not allowed to even touch 'their' property.
    2. I certainly can't swap it for my own.

    I would liek to try my own regulator. bugger it up and see, (they're cheap-as-chips, say USD20-25) but I need to tread carefully or I am on the ragged edge of illegal. Here that gets serious. Wiser to circumvent the issue, 'cos I'm old enough to knwo you can't argue with 'irrational' because 'irrational' will always win.
    Last edited by BritCNGUser; 06-05-2015, 02:27 PM.

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  • hypermilinggx
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    Brit, That pressure regulator is not really a safety device unless they vary the street pressure a lot. Have a service tech from the gas company come over and explain to him your situation and that you are going to regulate the pressure at each appliance. They might remove it for you.
    Last edited by hypermilinggx; 06-03-2015, 03:59 PM.

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  • cowboy
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    brit I said buy a new one for a reason than it is your regulator that you are buggering up not theirs. and I do think you will gain a lot. you have not damaged theirs. just keep theirs . you might scrounge a large hose 1 1/2 inchs would be my thoughts and just run it around the house to the compressor and see if the problem is fixed . keep in mind that a hose is not smooth like pipe to it will have more drag than pipe so it has to be bigger.

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  • BritCNGUser
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    What you say makes perfect sense, rip the guts out of 'their' regulator, having it sit as a fitting, but here in the UK messign with something that is not even my property (and is intended as a safety device) really is a handcuffs-job. Right too, you can't allow idiots to do that sort of thing. Whilst I can assure all, I am no idiot, that'd count for nothing if it went 'swanny-river'. Let me assure you, compressing gas is already too much of a leap for 'them' to be coping with. and I don't think I will gain all that much advantage anyway. CNG is unheard of here and in this respect the UK is way, way behind the rest of the world. Most have barely heard of LPG. So CNG.... forget it. As for you lot doing this? Stop this minute... Clearly you're all 'loons'
    Last edited by BritCNGUser; 06-03-2015, 06:23 AM.

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  • karl
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    +1 on cowboys idea

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  • cowboy
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    hi brit if it was me I would buy a new regulator and take it apart if possible and gut it or drill the guts out of it and plug any vent holes just make a fitting out of it. might just take it to your local machinist and have it gutted. and than install it in place of the gas co regulator and install point of use regulators everywhere except the compressor. my thoughts are they will never notice. that a new regulator has been installed. you know the left hand not knowing what the right is doing. as you cant fix stupid and I dont think they are going to oblige you by raising your street pressure. now keep in mind this is my opinion of what I would do if I had only one lb of pressure. you are free to do as you please. I think I might put a regulator just before your compressor in case one day to raise the street pressure just make sure it has a really big orfice like 3/4 or 1 inch so as not to restrict the flow. one day we will get together and kill a pint or two
    Last edited by cowboy; 06-02-2015, 08:04 PM.

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  • BritCNGUser
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    Thanks, had a decent break with my 9YO boy in a trashy holiday-camp, his long sufferin' father was to do the sort of thing he loves, roller-coasters and all things vomit inducing. Gawdhelpus... four days of it, I'm getting too old

    The pump can't be moved any closer to my meter, I'm reckoning on having to simply bite the bullet and big-up the supply. As someone above suggested, [considering I have naff-all pressure] I could ideally throw 'their' regulator and put individual regulators to each of my heating appliances, leaving my pump fed straight from the street. Only I'm sure I'll not be allowed that stunt. I can see how it would be nice, but it leaves no saftey margin so not clever, just clever, clever!
    Last edited by BritCNGUser; 06-03-2015, 05:44 AM.

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  • cowboy
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    good afternoon brit hope you enjoyed your time away. have you thought of moving your compressor and putting it next to the meter and running the high pressure to where you need it you could run it in ss tubing and just put the hose on the end.

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  • BritCNGUser
    replied
    Re: look what I found lurking in my 3rd stage head (MCH5)

    x
    Brit I think u need to drop 75$ on a new reg. I'll be in London in sept. To give u the 2 psi spring and whatever spares u want pm or Skype me
    Thank you for the offer. If that is not a handshake to Anglo-US relations I don't know what is?! [I have to say your average Yank can expect a soft-ride from your common or garden Brit too] but I reckon it'd do me no good. You see, I don't have the pressure in the first instance. I think I am losing what littel i have with far too many 90 degree bits of copper and 3/4" at my lowly pressures is killing it. The pipe coming into my home is 3/4" and 35mBar (at most) before my regulator, so I think I have to be very careful and go up to 1" or bigger (presently 3/4") after to my meter to stop the pressure drag and rerun everything to take out the stupid number of 90 degree bends I now have. Before I do thsi I think a lash-up with a quick-test using large bore flexible hosing is in order. Just to check to see if I'm right before I dig up my floorboards etc etc

    Red head:

    With the red hose coming off it in this pic, I have a Coltri made Priority valve



    I notice that below about 50 bar on the 3rd stage that my 2nd stage gauge climbs to 45Bar and then drops like a stone to about 32-35 bar as the 3rd stage pressures-up. This happens for less than a minute so not an issue for me because my PV is set to 130-140 Bar so it settles but the Red head valves seem to like back-pressure to seat ( or I think that is what is happening or it could be yet another symptom of my under-supply?). I have now tried two set of the red-head valves and observed much the same thing. Without a PV I am not sure how I would fare, it would instead run for ages until my tank was up to 50bar pressure. So for this alone I thank my PV. The effect is not so pronounced pulling air, so I think it is more likely my under-supply but bear my experience here in mind. Incidentally once the 3rd stage is over 50 bar and it preesures to 200bar, the second stage gradually climbs to 38-40 bar as it should.
    Attached Files
    Last edited by BritCNGUser; 08-01-2015, 04:53 PM.

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