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Re: [mad_scientist] Re: restoring Welch belt type vacuum pumps

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  • Vaughn Mcdowell
    I checked out your recommendation for the Dririte cartridge on line; looks like exactly what I need; I have an experimental setup based on what I have found on
    Message 1 of 7 , Sep 16, 2012
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      I checked out your recommendation for the Dririte cartridge on line; looks like exactly what I need; I have an experimental setup based on what I have found on the Bell Jar and SAM's FAQ that is a connection between the chamber to be evacuated and the vacuum pump input; where a shutoff valve is placed immediately at the input of the chamber; Also between the vacuum pump input and the valve is another valve connecting to the outside air. The idea here is to prevent the pump (and motor)  from being strained having to start up under vacuum. Most of this was constructed from parts I had accumulated over the years; I have been using an IronForce water trap used of air compressors at my air intake; it looks like your recommendation is much better.


      I also checked out the MasterCool Deep Vacuum oil also on line; the price look very good; I certainly want to investigate it further. As I have previously mentioned I use pumping oil for flushing based on the Welch manual recommendations; especially when I have serious water vapor problems that I can't get rid of. Afterward I replenish using pumping oil rated for vapor pressure of at least 10-4 torr up to 10-6 torr.  I an conducting some experiments with my mechanical pumps and eventually go back to my diffusion pumps when I get some problems ironed out.

      It looks like I got my single stage Welch 1373 (apparently no longer produced) working at least from what I can tell using my thermocouple  vacuum gauges; however this was done by long tedious trial and error; I am hoping someone can give me its rated RPMs ; I have had to operate it lower than the  old type 1405; I don't think the 1373's vanes are sticking requiring lower RPS to operate.


      ________________________________
      From: Vaughn Mcdowell <vaughn.mcdowell@...>
      To: mad_scientist@yahoogroups.com
      Sent: Friday, September 14, 2012 7:49 AM
      Subject: Re: [mad_scientist] Re: restoring Welch belt type vacuum pumps


      Thanks for taking the time to respond; I get frustrated trying to get information on line; especially items no longer in production. I certainly appreciate your input. One type pump I bought from Ebay that I am very happy about is an old 1405; but that was after flushing it a lot with expensive oil. Welch still produces this model but it does not resemble in any way the old one. I tried looking for archives on line trying to get information about the old version and got nowhere ; strangely I found what looks exactly like it from the patent office; apparently their first filing in 1939!

      Thanks again


      ________________________________
      From: Terrance <evilterrance@...>
      To: mad_scientist@yahoogroups.com
      Sent: Thursday, September 13, 2012 6:21 PM
      Subject: [mad_scientist] Re: restoring Welch belt type vacuum pumps


       
      Here's my best attempt to answer your questions (I wish I could be more helpful):

      1) I can't speak towards price, however, I use MasterCool Deep Vacuum oil. I haven't had any trouble with this product.

      2) I was never able to find manuals online for my pump. I can't help you here.

      3) I've seen this effect too. First, my chambers seals need a bit of pressure (vacuum) before they start working, so I will often push down against the seal when I first turn the pump on. I also see the effects of outgassing. In this case it will pump down to some value, then seem to pause for an unspecified amount of time, then continue towards its maximum vacuum once the outgassing finishes. I've also seen this behavior when the reed valve isn't just right (bent, needs a shim or needs a shim removed, crud on its surface,etc.).

      Yes, the Dririte cartridge is to remove any moisture. Once your oil has any amount of water in it, reaching deep vacuum becomes impossible. I believe the Dririte works better than a balast for water vapor, but if you have other condensing contaminates you might still need a balast.

      My $15 rebuild kit came with cork gaskets, new vanes w/ springs, a reed and assorted shims.

      I'm trying to find the place I got my kit from, the gentleman I spoke with there was extremely knowledgeable about these pumps and the prices were much lower than I could find online. It might be worth your time to make a few phonecalls to those kind of companies, just to pick their brains. If I find the place I used, I'll post back.

      -Terrance

      --- In mad_scientist@yahoogroups.com, Vaughn Mcdowell <vaughn.mcdowell@...> wrote:
      >
      > Thanks for responding; wow I have lots of questions; I will keep it down to a few at a time:
      >
      > 1) what is the lowest cost pump oil that can be used for flushing, I found a few on E bay but am not sure; one of my pumps is a 1373 single stage that I am trying to restore; it requires lots of oil.
      >
      > 2) Is there a archive Web site where discontinued pump manuals can be found? I have found a parts layout for the 1373 but no other information like its operating RPMs ; or info regarding the old style 1405; then there are old 1400 models without the ballast valve; but there seems to be only a sealed threaded screw cap instead ( no O ring) ; were these pumps manufactured prior to Welch's ballast valve patent in the mid 50's I believe?
      >
      > 3) The pumps that I have without the ballast seem to take forever to start pumping down ( at least thats what my TC gauge says) then all of a sudden they start pumping down ; is this normally due to water condensation in the oil? That is without having a ballast? The Dririte cartridge you mentioned is that a water vapor trap? Also did the $15 rebuild kit include gaskets??
      >
      >
      > ________________________________
      > From: Terrance <evilterrance@...>
      > To: mad_scientist@yahoogroups.com
      > Sent: Thursday, September 13, 2012 10:19 AM
      > Subject: [mad_scientist] Re: restoring Welch belt type vacuum pumps
      >
      >
      >  
      > I rebuilt a Welch pump last year. The rebuild kit was under $15. Once rebuilt, it now pumps down to 27-28 in/Hg.
      >
      > I put a Dririte cartridge on the input to help the oil last longer, this has helped a lot.
      >
      > Did you have any specific questions about these pumps?
      >
      > -Terrance
      >
      > --- In mad_scientist@yahoogroups.com, "Vaughn Mcdowell" <vaughn.mcdowell@> wrote:
      > >
      > > I have purchased several Welch vacuum pumps from Ebay on a beer budget, most needed cleaning;with my limited experience I have had some success getting them , as best as I can tell, in the micron range; some simply only required lots of flushing; some I had to take apart clean and restored with gaskets; even so high grade vacuum pump oil is expensive (even with flushing oil) especially having to flush many times. I plan to do some more work on my pumps; but need to keep it on a beer budget; anyone out there who has worked on Welch belt drive pumps?
      > >
      >
      >
      >
      >
      > [Non-text portions of this message have been removed]
      >




      [Non-text portions of this message have been removed]
    • Vaughn Mcdowell
      I found the manual to the old Sargent Welch 1405 vacuum pump on this link in case anyone is interested:
      Message 2 of 7 , Sep 18, 2012
      • 0 Attachment
        I found the manual to the old Sargent Welch 1405 vacuum pump on this link in case anyone is interested:
        http://www.liberatedmanuals.com/TM-10-4310-391-13-and-P.pdf



        ________________________________
        From: Vaughn Mcdowell <vaughn.mcdowell@...>
        To: "mad_scientist@yahoogroups.com" <mad_scientist@yahoogroups.com>
        Sent: Sunday, September 16, 2012 9:27 AM
        Subject: Re: [mad_scientist] Re: restoring Welch belt type vacuum pumps


        I checked out your recommendation for the Dririte cartridge on line; looks like exactly what I need; I have an experimental setup based on what I have found on the Bell Jar and SAM's FAQ that is a connection between the chamber to be evacuated and the vacuum pump input; where a shutoff valve is placed immediately at the input of the chamber; Also between the vacuum pump input and the valve is another valve connecting to the outside air. The idea here is to prevent the pump (and motor)  from being strained having to start up under vacuum. Most of this was constructed from parts I had accumulated over the years; I have been using an IronForce water trap used of air compressors at my air intake; it looks like your recommendation is much better.


        I also checked out the MasterCool Deep Vacuum oil also on line; the price look very good; I certainly want to investigate it further. As I have previously mentioned I use pumping oil for flushing based on the Welch manual recommendations; especially when I have serious water vapor problems that I can't get rid of. Afterward I replenish using pumping oil rated for vapor pressure of at least 10-4 torr up to 10-6 torr.  I an conducting some experiments with my mechanical pumps and eventually go back to my diffusion pumps when I get some problems ironed out.

        It looks like I got my single stage Welch 1373 (apparently no longer produced) working at least from what I can tell using my thermocouple  vacuum gauges; however this was done by long tedious trial and error; I am hoping someone can give me its rated RPMs ; I have had to operate it lower than the  old type 1405; I don't think the 1373's vanes are sticking requiring lower RPS to operate.


        ________________________________
        From: Vaughn Mcdowell <vaughn.mcdowell@...>
        To: mad_scientist@yahoogroups.com
        Sent: Friday, September 14, 2012 7:49 AM
        Subject: Re: [mad_scientist] Re: restoring Welch belt type vacuum pumps


        Thanks for taking the time to respond; I get frustrated trying to get information on line; especially items no longer in production. I certainly appreciate your input. One type pump I bought from Ebay that I am very happy about is an old 1405; but that was after flushing it a lot with expensive oil. Welch still produces this model but it does not resemble in any way the old one. I tried looking for archives on line trying to get information about the old version and got nowhere ; strangely I found what looks exactly like it from the patent office; apparently their first filing in 1939!

        Thanks again


        ________________________________
        From: Terrance <evilterrance@...>
        To: mad_scientist@yahoogroups.com
        Sent: Thursday, September 13, 2012 6:21 PM
        Subject: [mad_scientist] Re: restoring Welch belt type vacuum pumps


         
        Here's my best attempt to answer your questions (I wish I could be more helpful):

        1) I can't speak towards price, however, I use MasterCool Deep Vacuum oil. I haven't had any trouble with this product.

        2) I was never able to find manuals online for my pump. I can't help you here.

        3) I've seen this effect too. First, my chambers seals need a bit of pressure (vacuum) before they start working, so I will often push down against the seal when I first turn the pump on. I also see the effects of outgassing. In this case it will pump down to some value, then seem to pause for an unspecified amount of time, then continue towards its maximum vacuum once the outgassing finishes. I've also seen this behavior when the reed valve isn't just right (bent, needs a shim or needs a shim removed, crud on its surface,etc.).

        Yes, the Dririte cartridge is to remove any moisture. Once your oil has any amount of water in it, reaching deep vacuum becomes impossible. I believe the Dririte works better than a balast for water vapor, but if you have other condensing contaminates you might still need a balast.

        My $15 rebuild kit came with cork gaskets, new vanes w/ springs, a reed and assorted shims.

        I'm trying to find the place I got my kit from, the gentleman I spoke with there was extremely knowledgeable about these pumps and the prices were much lower than I could find online. It might be worth your time to make a few phonecalls to those kind of companies, just to pick their brains. If I find the place I used, I'll post back.

        -Terrance

        --- In mad_scientist@yahoogroups.com, Vaughn Mcdowell <vaughn.mcdowell@...> wrote:
        >
        > Thanks for responding; wow I have lots of questions; I will keep it down to a few at a time:
        >
        > 1) what is the lowest cost pump oil that can be used for flushing, I found a few on E bay but am not sure; one of my pumps is a 1373 single stage that I am trying to restore; it requires lots of oil.
        >
        > 2) Is there a archive Web site where discontinued pump manuals can be found? I have found a parts layout for the 1373 but no other information like its operating RPMs ; or info regarding the old style 1405; then there are old 1400 models without the ballast valve; but there seems to be only a sealed threaded screw cap instead ( no O ring) ; were these pumps manufactured prior to Welch's ballast valve patent in the mid 50's I believe?
        >
        > 3) The pumps that I have without the ballast seem to take forever to start pumping down ( at least thats what my TC gauge says) then all of a sudden they start pumping down ; is this normally due to water condensation in the oil? That is without having a ballast? The Dririte cartridge you mentioned is that a water vapor trap? Also did the $15 rebuild kit include gaskets??
        >
        >
        > ________________________________
        > From: Terrance <evilterrance@...>
        > To: mad_scientist@yahoogroups.com
        > Sent: Thursday, September 13, 2012 10:19 AM
        > Subject: [mad_scientist] Re: restoring Welch belt type vacuum pumps
        >
        >
        >  
        > I rebuilt a Welch pump last year. The rebuild kit was under $15. Once rebuilt, it now pumps down to 27-28 in/Hg.
        >
        > I put a Dririte cartridge on the input to help the oil last longer, this has helped a lot.
        >
        > Did you have any specific questions about these pumps?
        >
        > -Terrance
        >
        > --- In mad_scientist@yahoogroups.com, "Vaughn Mcdowell" <vaughn.mcdowell@> wrote:
        > >
        > > I have purchased several Welch vacuum pumps from Ebay on a beer budget, most needed cleaning;with my limited experience I have had some success getting them , as best as I can tell, in the micron range; some simply only required lots of flushing; some I had to take apart clean and restored with gaskets; even so high grade vacuum pump oil is expensive (even with flushing oil) especially having to flush many times. I plan to do some more work on my pumps; but need to keep it on a beer budget; anyone out there who has worked on Welch belt drive pumps?
        > >
        >
        >
        >
        >
        > [Non-text portions of this message have been removed]
        >




        [Non-text portions of this message have been removed]
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