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What valve(s) for safety in oil supply system?

seized123
seized123 Member Posts: 297
I have an above ground oil tank that feeds the oil burner which is 5-8 ft. lower in the below ground basement. It's a two-pipe system (which I may change to one-pipe).

Is there an oil equivalent to a whole house water shutoff valve that I can have put on at the tank? The only valves on the lines now are inside: a Firomatic just before the filter which is just before the fuel pump, and another Firomatic on the return line (which I have learned on this site might be improper). I usually turn off the heating system when I go away in warmer weather, but I have learned there is something called the siphoning effect, and would REALLY like a way to shut off the supply at the tank.

I am going to have the whole system inspected and updated, largely based on some very valuable advice I have received on this website (mostly in another thread, "Is this barometric damper installed okay?", which became a discussion of the supply lines as well as the damper, and has photos of the lines) but as I am going away soon I would like to have the oil company come out and put some kind of stopgap valve in so I do not have to worry about the lines or fittings possibly leaking forever when I am gone.

The above ground tank is in a big plastic tub with another plastic inner tub, so I am not so worried about the tank right now, but the lines come out of the tub and are exposed and go through the wall, and all things being equal it seems to me that a valve right where the lines come out at the top of the tank would make sense, since then any leak or damage between the tank and the lines would not be fed by siphoning.

I have heard of Oil Safety Valves (OSV's) and anti-siphoning valves, what is the difference and which would be good for me? Or for now would I just want some kind of manual ball valve? (The anti-siphoning valve, just from the name, seems like a possibility, even though it's not manual, if it can be installed at the tank.) Oh, another thought: in a two-pipe system, can the return line siphon out oil as well? Do I need to have a valve or valves on both for the assurance I'm looking for?

As I mentioned, I intend to follow some of the advice I have received on the other thread regarding fittings, etc. (@STEVEusaPA, @Big Ed_4, @Mad Dog_2 and others were especially specific on the supply lines) and also I will have the whole system evaluated in person, but this is for an installed-now-for-peace-of-mind-at-the-tank cutoff type of thing.

All advice welcome, and I can provide photos.





Comments

  • PatN
    PatN Member Posts: 19
    The three listed below are a good starting point. Chose wisely.

    https://www.preferred-mfg.com/products/fuel-handling/fuel-oil-components/valves/anti-syphon-These
    Anti-Siphon Valves | Preferred Utilities Mfg
    Installed in a vertical position at the highest point in the suction line with no part of the line between the valve and the tank below the maximum oil storage level. UL listed; Approved by the New York City Board of Standards and Appeals.
    www.preferred-mfg.com

    http://www.haseloh.ca/oil-safety-valve.html
    Oil Safety Valve
    oil line safety valve, oil tank safety valve, oil safety valve
    www.haseloh.ca

    https://www.websterfuelpumps.com/osv.htm

  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    There are no shutoff valves at the tank? Really?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • seized123
    seized123 Member Posts: 297
    Thanks @PatN. And @Jamie Hall there’s nothing at the tank, just Firomatics inside.
  • seized123
    seized123 Member Posts: 297
    Supply and return lines at top of tank, and going from outside of plastic tub to wall.

  • Mad Dog_2
    Mad Dog_2 Member Posts: 6,919
    O.S.V.  oil safety valve.  When we would sub boilers for Petroleum, every tank got one.  Mid 1990s. Mad Dog 🐕 
    STEVEusaPA
  • seized123
    seized123 Member Posts: 297
    So I figured out what I need with you guys’ help and @STEVEusaPA and others on another thread that became a discussion of my supply and return lines, plus I found the New York State Mechanical Code online:

    What I need is an anti-siphon valve on the supply line at the tank, required by section 1301.4 of the code, and to remove the Firomatic on the return line, since ALL valves are prohibited on return lines by section 1305.4.

    Apparently neither my former plumber nor the oil company tech who came out to look had any idea of either of these. The oil tech appeared not to have heard of an anti-siphon valve.
  • pecmsg
    pecmsg Member Posts: 4,844
    seized123 said:
    So I figured out what I need with you guys’ help and @STEVEusaPA and others on another thread that became a discussion of my supply and return lines, plus I found the New York State Mechanical Code online:

    What I need is an anti-siphon valve on the supply line at the tank, required by section 1301.4 of the code, and to remove the Firomatic on the return line, since ALL valves are prohibited on return lines by section 1305.4.

    Apparently neither my former plumber nor the oil company tech who came out to look had any idea of either of these. The oil tech appeared not to have heard of an anti-siphon valve.
    Send a carefully worded E Mail to the oil company and inform them. If they want your business they’ll correct the issues. 

    At the very least it puts them on notice there’s liable 
    CLamb
  • seized123
    seized123 Member Posts: 297
    Good idea.

    Here’s what’s been bothering me, though:

    With no valve of any kind on the return line as the code appears to require, how could you possibly service anything involving that line between tank and burner? If you remove the pump cover to replace the strainer, or want to replace the pump, or if the return is leaking at the pump, whatever, wouldn’t oil siphon out the line if you disconnected it? There must be two-pipe systems out there with no valves as per code, what do pros do to deal with this?
  • pecmsg
    pecmsg Member Posts: 4,844
    seized123 said:
    Good idea.

    Here’s what’s been bothering me, though:

    With no valve of any kind on the return line as the code appears to require,
    There must be two-pipe systems out there with no valves as per code, what do pros do to deal with this?
    Carefully
     
  • seized123
    seized123 Member Posts: 297
    Makes sense but there must be something specific you do for such a repair with a tank above the burner like mine to stop the flow of oil, otherwise wouldn’t it be everywhere?

    (BTW, this same discussion is now going on in parallel in another thread about my barometric damper, sorry about that.)
  • pecmsg
    pecmsg Member Posts: 4,844
    50’ of 3/8” copper holds 1/3 a gallon 
    just be careful 
  • seized123
    seized123 Member Posts: 297
    Got it, it’s 1/2 in. but either way wouldn’t it siphon, being far below the tank?
  • pecmsg
    pecmsg Member Posts: 4,844
    Than If the return IS below the surface of the oil YES it WILL siphon until air breaks the siphon. 
  • seized123
    seized123 Member Posts: 297
    So how do you deal with that?
  • CTOilHeat
    CTOilHeat Member Posts: 56
    With your set up, shut the supply line firomatic off, drop the oil filter, then run the burner until it reset a couple times. This will push the oil in the return line into the tank and also test the primary controls lockout function, which is pretty important.
  • seized123
    seized123 Member Posts: 297
    Wow! Thanks @CTOilheat! Very deep. Push return oil with pump. I would not try this myself, I’d be too paranoid about it not working and getting siphoning oil I couldn’t stop, but now I have an idea how a pro might do it. I have this discussion going on two threads, so need to stop on this one, but I might mention your method on the other thread.