Remove Flow check valve with new pumps?

TAG

My 30 year old Buderus panel/ floor radiant system is in need of some maintenance. The original plastic modular Embassy manifolds are starting to drip -- two of the three. Two of the pumps are original ... another is at least 15 years old and the other about 5 when I replaced the original Buderus DHW indirect tank

Not wanting to reinvent the wheel or do any piping changes, I purchased the Embassy parts to fix the manifolds. The layout was pumping away -- used the old school flow checks. Should I just keep the flow checks or use the included checks that are standard with the new pumps? Open up the flow checks I guess.

Have two new Alpha pumps plus a spare single speed Grundfoss pump w/o a check that I bought when I put the indirect in to have a spare. I'm not sure if I can add a check valve to it. I can always order another Alpha and keep the indirect running with the old school cast iron flow check and the never used single speed.

Other than a couple flushes I have never touched the Cast Iron gas boiler -- The Honeywell control, vent damper and water feed have been replaced over the years. Uses a Buderus 3220 Eccomatic w/ two heat curves and DHW for control

Have a new expansion tank and temp/pressure gauge to go in while it's open. Can anything go wrong with those old flow valves? Two would be easy to remove if that's better>

Alan (California Radiant) Forbes

Are they the Taco flow checks? They seem to be bulletproof, so I would leave them in for sure. If they are just the simple swing or spring check, I'd even leave those in compared to the plastic ones they give you for the -IFC pumps.

I just removed this flow check from the suction side of a Grundfos pump.

TAG

The one to the indirect is Taco (green) the other three are Amtrol (red). Not swing or spring .... these are the large cast iron things with three possible connection points and the screw on top. For whatever reason I have a spare from B&G in a box (also red).

EBEBRATT-Ed

@TAG

You could install pumps with checks in them and then leave the original flow checks open. If the internal check ever fails you could just take it out & Replace or go back on the original

hot_rod

Alan (California Radiant) Forbes said:

Are they the Taco flow checks? They seem to be bulletproof, so I would leave them in for sure. If they are just the simple swing or spring check, I'd even leave those in compared to the plastic ones they give you for the -IFC pumps.

I just removed this flow check from the suction side of a Grundfos pump.

So that check went all the way around the circuit somehow? or was it improperly installed on the suction side?

Alan (California Radiant) Forbes

So that check went all the way around the circuit somehow? or was it improperly installed on the suction side?

That's funny, hot rod. It was off a Viessmann 222-F combi boiler with proprietary pumps and I have no reason why they were installed on the suction side. The check was frozen closed and it took a long time to find it in its hiding place.

@TAG Those cast iron, weighted flow checks are great and have never seen one go bad.

Steve Thompson (Taco)

Funny fact is I believe decades ago we tried to develop a circ with the check at the eye of the impeller (inlet). Might be one of those.

Typically you'll see the check that comes with Taco circs mounted on a cardboard insert in the box - up to the application and you guys if you want to use it. BTW, almost all of us circ manufacturers use Neopearl check inserts - color determines the temp rating. Lastly, I don't see the point of more than one check valve on a circuit.

Short story for you folks. Names have been changed to protect the innocent. There was a Project Manager from an overseas pump company that created a bill of material for a flange accessory kit package - kind of cool. Swivel flanges, check valve (yes, part of the companion flange), nuts, bolts and gaskets. The only problem bill of materials had 2 check inserts in each package. I wonder how much flow the system would see if there was a check going one way on the inlet and a second on the discharge going the other way? Think about it! Murphy's law at it's finest.

Caught the oops before any left the factory so the story goes.

hot_rod

My preference is the Neoperl type checks for hydronics. They are very flow friendly and 100% "bubble tight seal.
I'd like to see them a distance from the circulator outlet, ideally. This keeps them out of turbulent flow conditions.
My concern with weighted checks is how well they open, or open completely with variable speed circulators? I know swing checks, often oversized on hydronics, can clatter under low flow conditions.
If you size them by Cv not pipe size the gate should be forced completely open under design flow rate.

I have heard from the field that the white colored, lower temperature polymer checks can fail in 3- 5 years under high temperature conditions, constant 180° plus for example. The black colored Neoperl have a higher temperature rating. They are also available in different "pop" rates and can be customized.

Neoperl has one of the most colorful displays at the AHR show, interesting folks to chat with also. They build the checks for faucets, BFD, and also flow aerators.

Steve Thompson (Taco)

Agree Bob - well said.