Results 1 to 9 of 9

Thread: Anti-vac valve

  1. #1
    Senior Member skydragondave's Avatar
    Join Date
    Apr 2010
    Posts
    105

    Anti-vac valve

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi all,
    Does anyone know what material the anti-vac valve O-ring is made out of? Is this standard 70 durometer rubber, or is it neoprene? Mine has gone hard and is leaking.

    Also, should there not be a spring inside the valve to hold it against its seat? When I took it apart there was just the brass bell with o-ring behind it and it was just dangling loose agains the e-clip. The NS Appia parts book does not break down the valve and I'd rather just replace the 2 o-ring than wait for the valve to come in. Nothing wrong with the valve just needs a new o-ring and (possibly) spring.

    Thanks again

  2. #2
    Senior Member GregWormald's Avatar
    Join Date
    Jul 2007
    Posts
    2,288
    It is a high-temp rubber ring--and there is no spring. When there is no pressure in the tank the piston drops down. When the tank heats up, the force of the steam lifts the piston against the seal.

    Greg

  3. #3
    Senior Member skydragondave's Avatar
    Join Date
    Apr 2010
    Posts
    105
    What upper-temperature limit should I be shooting for? I'm going to go in to a local MRO shop that specializes in bearings, seals and gaskets. Also, I heard about the Giotto machines having an updated antivac design that makes it more reliable. Would it be possible to interchange it with this one?

  4. #4
    TC
    TC is offline
    .
    Join Date
    Oct 2004
    Location
    Melbourne
    Posts
    14,665
    Not sure what you mean by upper temperature there? You may like to elaborate.

    The revised anti-vac goes back quite a few years now. We have been using this one which is a better quality all rounder. The bonus is that it's better quality and more reliable. It will also fit earlier giottos which didn't have the hole cutout in the cover plate under the top cover.

  5. #5
    Senior Member skydragondave's Avatar
    Join Date
    Apr 2010
    Posts
    105
    Hi,
    Just trying to determine what to ask for when I visit the MRO supplier on Monday. It could be a regular 70 or 90 durometer rubber O-ring, a silicone one, a neoprene one, it is black so Im pretty sure it isn't silicone though.

    By upper temperature I mean the highest temperature the o-ring would be exposed to. Thanks

  6. #6
    Senior Member
    Join Date
    Aug 2010
    Location
    Melbourne
    Posts
    373
    You'll want a Viton O-ring, sizing (for most anti-vac valves ) is 007 (5/32" nominal internal diameter).

  7. #7
    Senior Member robusto's Avatar
    Join Date
    Feb 2005
    Posts
    3,098
    In my Grimac the o-ring some time ago made the piston stick. I simply dug into my collection of various size o-rings for all purposes and found one which fit.

  8. #8
    Senior Member
    Join Date
    Jan 2010
    Posts
    131
    Do you change anti vac valves as preventative maintenance or wait for it to go wrong. Thanks in advance for any replies.

  9. #9
    Senior Member robusto's Avatar
    Join Date
    Feb 2005
    Posts
    3,098
    Quote Originally Posted by adjiland View Post
    Do you change anti vac valves as preventative maintenance or wait for it to go wrong. Thanks in advance for any replies.
    The machine will tell you when the valve needs attention. Perhaps a clean o,r fine emery cloth polish of the cylinder or a new o-ring.



Similar Threads

  1. anti vac on ecm giotto
    By JohnA in forum Brewing Equipment - Pointy End ($1500-$3000)
    Replies: 18
    Last Post: 18th October 2011, 11:37 PM
  2. Sticky La Cimbali Anti-Vacuum Valve
    By GCM58 in forum Brewing Equipment - Extreme Machines ($3000+)
    Replies: 25
    Last Post: 27th September 2011, 09:18 PM
  3. swapping out an anti-vac valve on VBM Super
    By Viscera in forum Brewing Equipment - Pointy End ($1500-$3000)
    Replies: 5
    Last Post: 21st July 2010, 07:06 PM
  4. Anti Suction Valve Leak
    By ento in forum Brewing Equipment (non-machine specific)
    Replies: 9
    Last Post: 30th January 2009, 01:02 PM
  5. Giotto problem - anti vacuum valve?
    By beetle in forum Brewing Equipment - Pointy End ($1500-$3000)
    Replies: 17
    Last Post: 3rd December 2008, 12:43 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •