Steamers eating checks....

Timco

Both mine and the customer’s, lol.

I have 2 industrial checks on a 1.8 mil system, 2” feed. The double check setup lasted a year.

What’s next? Both ends? Triple?

newagedawn

what r u talking about sir, lol

Timco

I have a very large steam boiler. 1.8 mil. Has collection tank. Tank is below boiler in another room. The checks on the feeder from tank to boiler keep failing. I had 2 industrial check valves on it and it lasted a year before water is running back from boilers to tank. It’s eating check valves and the customer will be writing another check. I was on my phone.

Looking to upgrade the check placement or use to stop this one final time.

Thanks for any thoughts.

Steamhead

What pressure is this system running?

Are there any chemicals in the water?

Timco

Steamhead said:

What pressure is this system running?

Are there any chemicals in the water?

Yes system is treated. 5psi. I have the pumps cut back on the feed with a BV above them. Helped a lot for loud slam sound.

Steamhead

Are the existing checks swing or lift type?

Jamie Hall

You're somewhat over my pay grade, but I'll chip in with two cents anyway: can you switch to pilot controlled slow closing checks? I used to specify such things on big water pumps...

Timco

Steamhead said:

Are the existing checks swing or lift type?

Swing. Industrial.

Timco

Jamie Hall said:

You're somewhat over my pay grade, but I'll chip in with two cents anyway: can you switch to pilot controlled slow closing checks? I used to specify such things on big water pumps...

They ship steam boilers here but no cool steam parts. I’ll have to order anything past standard checks. There’s cool how water stuff but no steam.

Steamhead

Timco said:

Steamhead said:

Are the existing checks swing or lift type?

Swing. Industrial.

Try industrial lift-type checks. They should be less likely to slam shut.

EBEBRATT-Ed

I like the angle pattern swing checks. You have to use 2 per ASME code 1 at the pump and 1 at the boiler. Are they using a lot of MU water?

a better fix would be have a motorized valve (belimo or other) with an end switch (if you have multiple boilers). The boiler pump control opens the valves the end switch starts the pump.

Low end China valves are crap. You have to pay $$ to get something decent.

Timco

EBEBRATT-Ed said:

I like the angle pattern swing checks. You have to use 2 per ASME code 1 at the pump and 1 at the boiler. Are they using a lot of MU water?

a better fix would be have a motorized valve (belimo or other) with an end switch (if you have multiple boilers). The boiler pump control opens the valves the end switch starts the pump.

Low end China valves are crap. You have to pay $$ to get something decent.

I have 2 at the boiler and one on each pump at tank. The two at the boiler are angle swing industrial. They were $$.

The big dog runs during winter, and now it’s an 800k just for DHW.

hot_rod

what is the failure, breaking. leaking, wearin the gate?

Timco

hot rod said:

what is the failure, breaking. leaking, wearin the gate?

Last ones was hinges and a groove in the seat. I’ll see what’s wrong with these when they approve a fix.

hot_rod

If the metal is being eroded away, often it is excessive velocity and/ or aggressive fluid.

Cavitation is a very powerful force, it can erode away most any material in short order.
High temperature really accelerates corrosion also.

No harm is having the water tested at the device if possible. It could be a combination of events.

I doubt the brass quality of a brand name brand valve would be an issue, most everyone uses DZ brass alloy now.

Timco

There’s a 2” BV above the 2) 1” lines from the duplex pumps. I had that off about 1/2 and it instantly stopped the banging. Better checks also helped. It’s double 2” at boiler horizontal and a 1” over each pump vertical. Pump checks were put in by maintenance guy and failed. Hinges flop. I’m doing all new industrial and speak to chemical guy. It’s real slimy water and low ph. System water very clear, some sludge in LWCOs and sight glass bases.

hot_rod

Maybe the checks are oversized? When a swing check gets oversized inadequate flow will cause the gate inside to float around mid position and chatter or bang. That will wear or destroy the valve quickly.

The Cv on a check is in the full open position and the valve needs that GPM to shove the gate open and out of harms way.

Check the Cv on the valve and compare to the actual flow rate passing through.

Often times a check can be several sizes smaller that the line it is connected to. If it is he style where the gate swings up and out of the flow path, for example, it will have a very high Cv.

Maybe a different style valve, as others mentioned would be a better fit?

EBEBRATT-Ed

You mentioned banging. Any possibility of the feed water flashing into steam? Water through a high resistance valve. just guessing. Is the feed water really hot??

gennady

The valves on the outlet of the pumps are control valves. their purpose to trottle the pump discharge. Restrict pump discharge and banging and check valve issue will go away.