Pulled After a Decade and a Half. Rebuilt for One Sixth the Cost of New.

HBE Automatic Recirculation Valves | Cooling Tower Makeup Water Service | Coal Fired Baseload Unit, Midwest

The Application

When one of the last new coal fired units in the country was being engineered, the design team had a problem that every plant engineer knows well. The cooling tower makeup water pumps could not be allowed to dead head. They needed constant flow, and that flow needed to circulate back into the cooling water system instead of being thrown away.

There are two ways to solve that. You can build an instrumented loop with a flow meter, a transmitter, a controller, a control valve, a separate check valve, and the wiring and calibration that goes with all of it. Or you can put in one valve that does the whole job by itself.

In 2006, working with Hayes Hesler, HBE Automatic Recirculation Valves were specified for the application and three were purchased for the project. Two went into service. One went on the shelf as a spare.

The Valve

Model NLPM-64-015-13360 B

  • Body: A216 WCB carbon steel
  • Internals: stainless steel
  • Inlet and outlet: 16 inch, Class 150 ASME flange
  • Bypass: 10 inch, Class 150 ASME flange

The NLPM is completely self contained and fully automatic, operated by the flow passing through it. No air. No electricity. No signal. In one body it acts as the main line check valve, senses main flow, modulates the bypass so the sum of main and bypass flow never falls below the pump’s minimum, and reduces bypass pressure so the valve runs quiet and free of flashing.

The Result

The unit went into commercial service and the valves went to work. No trouble calls. No failures. No adjustments.

We tell every customer the same thing: even when a valve is not giving you problems, pull it and look at it about every ten years. Not because we expect to find something. Because knowing is better than assuming, and a planned inspection beats an unplanned outage every single time.

The plant took that advice. In 2023, after roughly a decade and a half of continuous service, they pulled one of the operating valves and dropped in the spare that had been sitting on the shelf since 2006. The changeout was straightforward. The plant kept running.

Then they shipped the original valve back to us. We inspected it, repaired it, and returned it to them for inventory.

The rebuild cost one sixth the price of a new valve.

That valve is now the spare. The next time they pull one, the cycle starts over.

The Follow Up

The same approach is now being applied to the auxiliary cooling load at the same plant.

Model DLPM-40-015-13360 C

  • Complete with modulating bypass
  • Body: A216 WCB carbon steel
  • Internals: stainless steel
  • Inlet and outlet: 10 inch, Class 150 ASME flange
  • Bypass: 8 inch, Class 150 ASME flange

The Takeaway

A decade and a half is a long time in a plant. Instruments drift. Transmitters fail. Control valves get rebuilt and rebuilt again. This valve ran on flow alone, protected the pumps it was installed to protect, and when it finally came out for a look, it was worth repairing instead of replacing.

That is what we build. One moving assembly, stainless trim, and a design that does not need power to do its job. If you have pumps you cannot afford to lose, we will size a valve for your service.

HBE ENGINEERING, INC. | Since 1984 220 Day Dr, Three Rivers, MI 49093 Phone (269) 279-2035 www.hbe-engineering.com | sales@hbe-engineering.com

Short Version for LinkedIn

In 2006, working with Hayes Hesler, three HBE Automatic Recirculation Valves were specified for the cooling tower makeup water pumps at a new coal fired baseload unit in the Midwest. The pumps could not be allowed to dead head and needed constant flow circulating back into the cooling water system.

Two valves went into service. One went on the shelf.

We always tell customers to pull a valve and inspect it about every ten years, even when it is running clean. In 2023 the plant did exactly that. They swapped in the spare, sent the original back to us, and we repaired it and returned it to their inventory.

Cost of the repair: one sixth the price of a new valve.

Roughly a decade and a half of continuous service on cooling tower makeup water, no issues, and the valve came back rebuildable. They are now doing the same thing on the auxiliary cooling load.

That is a 16 inch Class 150 NLPM, carbon steel body, stainless internals, running on nothing but the flow going through it. No air, no electric, no signal, no calibration.

If you have pumps you cannot afford to lose, let us size one for your service. sales@hbe-engineering.com

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