Why would they do that?

tomhaeussler

Why would they pipe it like this? I don’t think the buffer tank is doing anything piped like that and l usually pipe a tube sheet boiler primary secondary

SuperTech

Huh? Pics please?

tomhaeussler

Oops l thought l put the picture on here guess l don’t know how anyway it’s a lochinvar tube sheet boiler 180,000 btu no primary secondary piping 8 zone valves and a buffer tank piped From the boiler outlet right to the same pipe 2 tees with a ball valve in between the tees

lchmb

now I really want to see the pictures...

tomhaeussler

Here’s the pic

SuperTech

They must have had a sale on ball valves?

kcopp

"Expansion" tank?

GroundUp

No expansion tank? No flow in the "buffer"/ water heater loop? What the crap is this? I don't think P/S is necessary here but this is goofy

the_donut

Such a tees with picture.

Zman

tomhaeussler said:

Here’s the pic

the_donut

Zman said:

tomhaeussler said:

Here’s the pic

Tees not tease

EBEBRATT-Ed

If I am not mistaken all those boilers need constant full flow. I wouldn't install one without primary secondary unless it was 1 loop with 1 pump and no zone valves

tomhaeussler

Ther is a floor mounted expansion tank between the boiler and the water heater/buffer tank this system is space heating only l just don’t know why they have that tank? This is an apartment complex and all the boilers are installed the same way and the way they piped the buffer tank I think is stupid it can’t be doing anything? Maybe I’m missing something? I’ve been doing this for a very long time and never seen this anywhere else? Yes I believe these boilers do need constant flow and there is a factory installed bypass pump and a wild leg I assume is for better flow when only 1 or 2 zones are calling

nicholas bonham-carter

Is that boiler a Lochinvar solution, which has a built in primary loop, if it is not clogged up. Has it had any maintenance?
If it has been oversized, (looks like an over 100k BTU), then a buffer tank will help.—NBC

SuperJ

Maybe you’re supposed to throttle that ball valve between the tees to force a bit of flow thru the buffer tank to add thermal mass? I would’ve said shut the ball valve but the pipe size is likely too small to get full flow thru the tank.
Other theory It’s just a hot water tank that can be use as backup by closing the ball valve between the tees. If you look closely at the label you’ll see a label warning of hot water burning someone’s hand in a sink.

GBart

Have no clue but Lochinvar makes a buffer tank and it doesn't look like that, but that is much cheaper, a hot water tank, oye.

http://www.lochinvar.com/_linefiles/BVU-01.pdf

GBart

wonder if that is a T&P valve in the tank?

GBart

Basically it's a sort of buffer or loop because the system water is too much for the boiler to handle when multiple zones call, that ball valve in the supply between the T's would have be manually set to keep the boiler temp from crashing when many zones call, it may work OK but it's certainly not textbook.

You would literally have to run the system with many zones calling to see what happens to the boiler temp and possibly adjust the ball valve, that's my best guess.

GBart

I suggest downloading the install manual for the boiler and see what piping is rec'd, primary/secondary loop perhaps? I dunno.

unclejohn

That tank is in the supply pipe. So if you throttle down the valve hot water will flow through the tank but why do that? You would start adding colder water to mix in with your supply at start up. So if only one zone was calling you would get a longer cycle. So maybe thats the reason.

GBart

yeah my guess was towards what they were thinking when they did it, another q is does it work as it is now???

tomhaeussler

It does work ok the valves are always in the position shown in the picture and they have several other buildings at this complex all boilers were installed the same way and as far as I know they all work ok I was just wondering what they were thinking?

GBart

I have no idea really

ratio

Maybe they weren't thinking? "This is the way we've always done it" kinda eliminates thinking.

HomerJSmith

I don't see the purpose of that buffer tank. The only way you have flow is to throttle down the ball valve and that isn't going to prevent short cycling. There are a lot of piping errors in this setup.

hot_rod

As is with that valve and fairly long distance between the tees it may be getting flow all the time. does the tank get hot? If so it is getting some circulation.

I'd imagine with all those zones that boiler short cycles on low load conditions.

If it were a true P/S and the tank had a circulator with temperature control it could be a buffer of sorts.