TRV HELP! They don't fit

JUGHNE

Old guys are just that way.......I have convinced myself that I don't want the method or even PEX. Keeps me out of jobs I don't want.

diesels12

Harvey pump on far right is same size as the 13 circulator pumps , see pics. Why is check valve necessary?

diesels12

Pics

Danny Scully

@JUGHNE, you should still be threading brass (or gal) for your waterlines then, and using oakum and lead for your hubbed cast iron waste piping!

JUGHNE

Maybe I do!

Harvey Ramer

diesels12 said:

Harvey pump on far right is same size as the 13 circulator pumps , see pics. Why is check valve necessary?

That pump comes with a check valve installed, so if no one removed it, you should be good. A check valve is necessary to prevent reverse flow through that loop in the event that only the indirect pump or airhandler pumps are running. The water in the loop must flow past the closely spaced tees where the boiler headers tie in, in order for the heated fluid to transfer into the system. Also, that pump must be able to provide a flow rate equivalent to the sum of the max combined flow rate of the pumps on the rad header. If it doesn't, you need a bigger pump.

The pumps on the rad header should also have their flow rates balanced. Do you have one pump per rad? If so, close the rad valve until you see a 20° dt @ the max operating temp. Do this on each rad. Your TRV's can control the rest.

The way we would typically set this up, is to have one constant pressure pump pumping into the rad header/manifold, balancing the flow, and then let the TRV's control the flow rates from there.
You may experience some velocity noise in your current setup, as the TRV's close on rads before the pump shuts off. Unless i am not grasping your control concept correctly.

diesels12

Harvey, I do not have TRV's installed yet, only 4 out of 40 due to problems not fitting. Existing valves are 100 years old and don't work, they are all in open position.
Are you saying the pump on the far right has to be as big as the combined 13 circulator pumps for rads, or just 1. As I stated prior, that pump is the same size as circulator pumps on rads but getting a pump equal to all 13combined would be a big pump. We are assuming we need a pump after mixing valve to pump the water past and into the 13 riser zones. Each riser zone feeds about 3-4 rads depending. We are patiently awaiting the tekmar repro arrive at his desk tomorrow and look at my posted YouTube videos to see his opinion. Of course your comments are greatly appreciated as sometimes the more Cooks in the kitchen the better.
Cheers
John

Grallert

Don't toss those pneumatic actuators. I would be interested if it's possible.

diesels12

System is up and heating fine now, I forgot to shut off a ball valve on end of loop. Will post full project pics and description next week after air handlers are running. Thanks everyone for the advice. Still looking for someone in NYC area to install these remaining TRV's if anyone is interested.

EBEBRATT-Ed

@Danny Scully

I admit it's fast as hell
Crimping a valve on a 4" water main when the existing valve doesn't hold is pretty sweet.

But the fittings cost $$

If you have a leak (I admit there rare) or just need to change something you usually have to cut out and waste a lot of fittings

You try and avoid "close coupling" the fittings for that reason but sometimes you can't

If you cut out a bunch of sweat fittings or black pipe and want to repipe with propress the radius of the propress fittings is larger and you end up having to repipe more than you want to make it fit. You can't always put it back together the same way as it was

Sometimes the reducing tees you want are not available without using more bushings or reducers which take up more room than you have.

tight spaces, inside a fan coil unit you usually end up sweating it anyhow because you can't get the gun in there.

difficulty keeping it straight. I know about alternate crimping.

Do the +++s oughtweigh the ---s??

Probably...............

But I don't have to like it

nicholas bonham-carter

Since you have so many zones, maybe you can do without the TRV’s. One plus is the fact that the original valves are all open.
With outdoor reset, you may still have the comfort you want.—NBC