20 Oct 2000 at 3:48 pm #273725Anonymous
I hope someone can help. I am trying to replace a Bell & Gossett zone valve and don;t know if it can be done while the flow is active and burning hot. I live in a condo, and they won’t turn the heat flow off as it affect everyone. So I am wondering if I remove the bonnet off the valve body, will it still be sealed, or will I get burned ? Any insight will be greatly appriciated.
21 Oct 2000 at 2:32 pm #288409
Many, if not most, condo systems have valves at the main lines to isolate each unit so they do not have to shut off and drain the whole system.
21 Oct 2000 at 4:21 pm #288410
One of my Condo accounts is 56 stories high and the only
“shut off’s” are at the boilers and at the roof level upfeed/down feed system.
What most “helpers” fail to realize is you honestly DO NOT want a positive shut off on a hot water heating system.
Think about it . A person not knowing that water can freeze if not moving (a helper for instance) would close a valve as to prevent the excessive heat that could happen with non electric zone valves or a failed aquastat/thermostat.
This in one of the reasons that the better zone control valves will have a minimum fail safe of 40 degrees to maintain piping integrity.
If you went to a plumbing supply and looked into the hydronic manual valves you would see a small hole in the valve disc/cylinder when it is in the “closed” position.
Personally if I were you id wait till the warmer months and ask for a shut down at the source then have non electric zone valves installed where you can modulate the exact temperature requirements you desire.
Even the best isolation valves will fail when used in larger heating applications as normally they are installed and forgotten about and the expansion and contraction does take its toll on the valves integrity.
You could also have only a branch valve that is common on heating/cooling systems with a fan coil and these normally have a washer type globe valve used for throttling and again the integrity is not always the best.
There are certain valves that do have a fail safe built in that we use that fail in the open position to protect against freeze ups.
Why not ask your building Supt. to either repair/replace your valve at the earliest opportunity and don’t take a chance of flooding out the place or scalding yourself.
21 Oct 2000 at 5:22 pm #288411
Thank you for the helpful info. Yes our condo only has 23 units, and only a main shut-off. I have a electric zone valve, that I am currently using manual control (only off or on) to regulate heat upstairs as the motor had burned out. I have asked a building associatation reguarding this problem; normally any heating problem is handled by the a contracted company in charge of the building maintananc, however this only covers problems with system, and nothing inside the units. And shuting it off for any non-critical reason or internal unit repairs requires a advance notice application to do so, at a cost of nearly $500. They have to called the contracted maintenance to shut off and reactivate it. (way too much hassle and cost to replace a zone valve.) Guess I’ll have to wait till spring and take my chances with luke warm water instead of scalding heat.
This could all be solved with ease if I could track down an old bell & gossett modumate model zone valve, but of course its discountinued and now where to be found.
Thanks all for the info, reallly appriciate it
21 Oct 2000 at 10:58 pm #288412
Hi Ptrout, The “only one shut off” is normal for a hydronic system as if you had more then one the helpers and handymen would shut everything in sight and forget to turn some thing on again.
Now that you have found life in the Condo world to be cruel you have one thing in your favor and that’s time to contact B&G (great company to work with) and give them the model number of your defective actuator.
The Valve body still maybe in good condition and only the operating module needs replacement.
Contact the buildings contractor and make him/her an offer they cant refuse for example.
As soon as the heating season ends contact them and say “lets make a deal as it is between heating and cooling seasons and you folks could use some fill in work”
Then ask for your best price as they will come when its convient for them (slow season)
Now being a contractor in plumbing/fire suppression systems/HVAC etc I never shut off a heating system unless it is a dire emergency during the colder months.
I am sure this contractor feels the same way.
Now as a boiler inspector I normally do 2 inspections per year as per ASME section IV code and the National Board of Boiler Inspectors
1- One Inspection is external while the system is firing and I jump out all the safety and operating controls and let the pressure build to maximum level thus forcing the relief/ safety valve to discharge (nerve wracking to say the least) especially on steam (POP)
2- The internal inspection is the one your concerned about as in this type of inspection they normally drain the system and physically inspect the stay bolts, mud drum, hand holes, fire box and looking for internal corrosion or possible stress cracking.
Durng this inspection you should have your defective valve replaced if you cant get a new electric controller OEM replacement. As the system should be down.
Then on refill, if you do have a problem the contractor is already there and your job is just added gravy to them as they are there any way so replacing your valve is no big deal.
Thankfully you didn’t go around arbitrary shutting off valves thinking that Most hydronic systems have isolation capabilities THIS is EXACTLY why Helpers should never not only be allowed to wonder around in a building unattended BUT they never should talk directly to client.
They just don’t have the education as they are still in the basics stage of these aspects of “plummmmin”
I have come behind many good intentioned helpers who could have gotten themselves very badly hurt and or destroyed equipment.
Remember most plumbing codes don’t bother to address heating other then very basic aspects like back flow preventers and sizing the flue and gas lines and free air for proper combustion.
Good luck and again try to talk to the building contractor and let them know when they do have a shut down for any reason you would like to have your work performed also This alone will save you the $500 shut down fee.
If you would like to know why the contractor is entitled to this shut down fee please ask and Ill be more then happy to explain as I get slightly over $1,500 for our shut down even for a minor repair.
Have a great week end.
22 Oct 2000 at 3:05 am #288413
The red-head Bell & Gossett zone valves permit removal of the actuator portion without draining the system. If you can see curved wires under the head, these are meant to be squeezed together to remove these clamps from a groove around the valve head.
If water is now dripping out under the electric actuator head then you could be burned by the water.
If the valve is dry, the valve seals are holding the water inside. When you remove the actuator the valve will be in the open position until you replace the actuator head.
If you are worried about this, get someone with experience to remove and replace the head for you.
22 Oct 2000 at 4:06 am #288414
Again thanks all, I am so glad I found this place, and even more so that I didn’t try anything stupid yet.
I did call B&G and did get a replacement, but it still needs a new bonnect (the seal).
Guess what though, B&G tech said “yes you can remove the seal with active flow” <---- bad advice ?
But alas this is all but minor problem now as I discovered that the bonnet screws are solder to the valve body. Sylvan is this standard procedure ???
Now its seems to do anywork, they may have to cut the valve out an put in a whole new section (a big job).
22 Oct 2000 at 6:31 am #288415
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