Metallurgical High Vacuum Corporation

August 2013

  • President's Corner

     

    news-president-corner It may look like USA manufacturing is indeed going off-shore, but we still have a lot of it here. "Built in the U.S.A." is still good thing to believe in.

    Now a lot of people may believe that you can make more money with the click of a mouse, but it is in the making of products that creates the jobs and payrolls that help our families and our country

    We recently finished and posted a short video that shows the skilled people in our facility making our "Survivor"TM brand of vacuum pumps. We have shown with field experience of over 350,000 hours they can last longer, require less maintenance, and pay back the initial investment many more times than cheaper alternatives.

     At MHV we believe in doing the best possible job for our customers. Quality comes first and last with us. We've grown our inventory of parts that we manufacture so customers don't have to stand in the back of a line or wait for the next boat shipment to arrive. That's what our online "Parts Express" was built for. We've even reverse-engineered components no longer being made to keep customers running.

    Here are some comments on "Made in the USA" from Ryan DeArment of Channellock Inc., a family owned manufacturer of excellent tools:

    "Channellock TM started out as a small operation making hand-forged horseshoe and blacksmith
    tools. George B. DeArment founded it back in 1886. We believe that American manufacturing is
    the backbone of the U.S. economy. The best designed and crafted products in the world, like
    Channellock TM pliers, come from the United States. American manufacturing employs workers and
    supports families.  Our founder believed that: "Dedication to excellence is the surest way to surmount
    adversity and to prosper."
    We still do."

    So whether it's replacement parts, or rebuilding your old pumps, MHV is dedicated to being your partner for the long haul. You can call for answers and speak to a helpful technical person locally, rather than in an overseas time zone. Isn't that much better?

    We'll be at the Heat Treating and Gear Technology Meeting in Indianapolis in September. So come by and say hello.

    The vacuum business is thriving here, and we want to help you. So e-mail me with your vacuum questions and we'll answer them: mhv@methivac.com

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  • Vacuum Tips: Looking for failure in the system

    It's Monday morning and you can't pump your workhorse furnace below 40 millitorr.  You have helium leak-checked the most obvious spots and there are no leak indications. You have bled in a "puff" of helium into the mechanical pump gas ballast valve port to verify that you are able to see helium. This sort of clears the blower and mechanical pump.  Your hunch is an internal water leak and the 40 millitorr you are seeing is the vapor pressure of the ice formed by the leak.  Before blowing down the water from the internal heat exchangers and furnace shell (a big messy time consuming  job!), you need to know if all that trouble is warranted. A diagram of a typical furnace is shown below to illustrate the test connections

     

    Isolate the Pumps

    The next step is to blank off the blower inlet and verify a vacuum level below 10 millitorr (blower running)test point B.  Note that with the blower at rest and the mechanical pump running, you will normally see 500-1000 millitorr at the inlet since you are pumping dirty roughing piping with high outgas loads through the low conductance internal clearances of the blower at rest.

    If the blank off is done by closing the roughing valve, you might have high blower inlet vacuum due to a seat leak on the roughing valve. To verify, helium needs to be sprayed into the valve seat/disc area but in most cases this cannot be done due to piping placement, etc. The fix is to drill a hole in the roughing piping near the roughing valve and TIG weld in an “O” ring sealed test port. (We make a mild steel port with an SAE “O” ring sealed plug for this purpose). This allows easy helium access to the valve seat (with the rough valve closed), and a leak tight seal with the piping under operating conditions.

     DIAGRAM

                    A diagram of a typical furnace illustrates the test connections.

    Digging Deeper
    Next to check are the vent and partial pressure valves. The argument on the roughing valves still applies here. You need to introduce helium on the upstream side of the valves (with them closed). The problem is most venting is done with nitrogen/ argon at 30-60 psi. This needs to be valved off and suitable piping changes made to allow helium to be bled in. The partial pressure valves are more easily checked since the piping is of smaller diameter and easier to disconnect or valve off. If not previously leak checked, remove the electrical junction box on the recirculating fan motor (if equipped) and probe the three phase power feedthrus and motor internal temperature switch feedthroughs. IMPORTANT: check voltage on the power leads with a DVM before probing! Certain air cylinders pose another problem if the vacuum seal on the rod is provided by the seal package on the nose of the air cylinder. This is the construction we have seen on an old vacuum oil quench furnace. Leak checking this construction means disconnecting the air line to the bottom cylinder port and applying helium.


    Finally, if there are vacuum/pressure switches piped into the furnace chamber, they need their covers removed and helium introduced to verify no diaphragm leaks.At this point you can be fairly certain that the problem is ice in the furnace. This can arise from water leaks on the internal heat exchangers (more common)or a hole in the furnace shell caused by corrosion of the water jacket ( a rare occurrence). Testing the heat exchangers will involve blowing out the water with compressed air, waiting several hours for the ice to melt, and with the leak detector valved in,bleeding in a slug of helium into the water line. Testing the furnace shell involves draining the shell (a big undertaking) and flowing helium into the water jacket.


    Some Other Techniques
    Another good method to locate water leaks is to add fluorescent dye into the process water system. Leaks can then be pin pointed using a “black light” source. If the heat exchanger is internal and to the rear of the furnace, the hot zone would have to be removed to gain access. Black light testing on the furnace shell and door would be fairly easy.

     

    All this can be eliminated if a residual gas analyzer (RGA) is available and connected to the furnace! A high water peak would point the way to a an internal heat exchanger or furnace shell/door leak while a high nitrogen peak would mean looking at the vent and partial pressure valving. A decent RGA system probably costs in the $30,000 range and makes sense for multiple furnace installations handling costly.

    Geoff Humberstone

     

     

     

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  • Manufacturing Capabilities Grow at MHV

    Advanced Technology at MHV

    Our capability for CNC manufacturing of shafts, main castings, and MHV-designed parts continues to grow. We not only employ precision CNC machining, vacuum welding, fabrication with leak checking-but offer the complete package including CAD design. Our newest machine is a Mazak Quick Turn 350-II with a hydraulic steady rest that enables us to turn out shafts and other parts accurately.

     

    We can't always wait for an OEM to deliver parts for ongoing projects and pump repairs. Sometimes the OEM does not even still make the part. That's why MHV has CAD/CAM capabilities to extensively engineer and manufacture parts from shafts, pistons, eccentrics etc.

                                                                                                                

    Here’s a group of main 412 shafts in process at Metallurgical High Vacuum.These shafts have longer key seats than the original design.
    Below is a Stokes 412 short block replacement made by MHV.                                   

     

      august2       august

     

    We've even designed and invested in patterns for casting the main housings on Stokes 412 pumps. We have them made by one of the premier great iron foundries in the US. We specify class 40 gray iron casting, BHN 220 – 2704 for long life. We also use brass core hole plugs for corrosion resistance. They are pressure tested at 50 PSI to verify integrity. MHV is the only source we know of for these castings which will save customers from scrapping their pump.

     

    Many customers come to us for new manifolds, chambers, and pumping systems which they cannot get from other suppliers. Our custom product design capabilities solve a lot of problems for customers. For example, we've even designed “hot swap" filters which enable a user to change filter cartridges with the pump operating saving production time.

     

    We love a challenge at MHV. Customers ask us for help and we are ready to serve their needs with our unique design and manufacturing capabilities, higher quality, and faster deliveries.

     

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  • Heat Treating Conference and Show at INDY

    The ASM Heat Treating Society and the American Gear Manufacturers Association are partnering to create an exciting mix of education, technology, networking and exposition opportunities - all at the 27th ASM Heat Treating Conference and Exposition and Gear Expo. Come to the Indiana Convention Center, Indianapolis, on September 16-18thto learn about the latest developments.

    Metallurgical High Vacuum will be in BOOTH # 1639Stop by and see our latest developments. Contact us by phone or e-mail if you need complimentary EXPO passes.


    Heat Treating Master Sessions  

     In addition to a comprehensive technical program at this year's show celebrating the 100-year anniversary celebration of the ASM Heat Treating Society (beginning as the Steel Treaters Club in Detroit), a highlight of the program will be three special Heat Treating "Master Series" Sessions that will focus on heat-treating pioneers whose research transformed heat treating technology.

    The sessions will include lectures by current experts in the heat treating field on the contributions and impact of past heat-treating "giants" Walter Jominy, Marcus Grossmann, and Edwin Northrup on heat-treating technology.

     

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  • Conversion Chart

    Here's a handy chart to have when you you need to change units. 

    MULTIPLY

    BY

    TO GET

         

    ATM

    760

    Torr

    ATM

    1013.25

    mbar

    ATM

    14.696

    PSI

    microns

    1.3328X10-3

    mbar

    microns

    1X10-3

    Torr

    microns

    133.28X10-3

    Pa

    l/min

    3.53X10-2

    CFM

    l/sec

    2.119

    CFM

     

     

     

     

     

     

     

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  • MHV Website

    Our web site continues to grow with more information and easier search capabilities.The URL is the same:www.methivac.com.

    The search box is at the top-right of each page. Just type in a part number or name into the box and click the enter key; a list of results will be displayed for you to pick the one you want. When looking for Stokes part numbers, please enter the full 9 digits and dashes.

    Things will be changing as we fine tune and add content. Our goal is to help our customers with useful information. 

    SPECIALS

     Here's a special deal on vacuum pump oil. 

    When you purchase a 55 gallon drum of Formula F Rotary Piston pump oil we'll give you a 5-gallon container of Formula H Blower lube oil free. (Offer valid through August 31, 2013).

    Shaft Seal Kit for 6" Blowers
    Customers have asked for a kit that resolves seal problems on Roots‚Ñ¢ 6-inch blowers by replacing the original lip-type seals with precision mechanical shaft seals.  The robust mechanical seals are designed to last longer and stand up to rugged operating conditions. In addition, they simplify future maintenance. Available "off the shelf".  

    Part Number RC-1011.

    Contact us for quotes and more information: (877) 787-9880  

     Call or write us with your questions, and let us know any suggestions and ideas you may have about the newsletter.   Click to E-mail 

     Feel free to call on our team at MHV to help with your vacuum needs. You'll find we can respond quickly to your requests.

     Sincerely, 

    Geoff Humberstone

    Metallurgical High Vacuum Corporation

    877-787-9880     www.methivac.com

    6708  124th Avenue, Fennville, MI 49408-9632

    Copyright (c) 2013--Metallurgical High Vacuum Corp. All rights reserved

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