A condensate return pump is a specialized device designed to transfer condensate (water) from an industrial steam system. Condensate is extracted from a heating system or process and pumped to the condensate return system, where it is returned to the boiler for reuse.
In certain situations, the system’s steam pressure can be sufficient to force the condensate through the steam traps and condensate return lines and back to the boiler room’s condensate holding tank. One or more condensate return pumps are needed in most practical situations to help overcome gravity, pressure drops from long piping runs, and back pressure in return lines.
Operation of the Condensate Unit
Condensate units, also known as transfer pumps, have a particular function. The objective is to return hot condensate from low points in the building as quickly as possible to the boiler system. The water/condensate ratio in the receiver increases as condensate flows down from the steam traps into the condensate receiver through gravity. In the receiver, there is a float or mechanical alternator. The pump starts and sends the condensate out of the receiver and back to the boiler room when the volume rises high enough to allow the contacts on the float.
Most condensate systems have two pumps, one of which serves as a backup. There is usually an alternator for the pumps when using two pumps. There can be two floats or a two-level mechanical float alternator with a higher level sensor in addition to alternation so that if the first pump fails, the second pump kicks in.
Condensate Return Pumps are either electrically powered centrifugal pumps or mechanical pumps that pump the condensate using steam pressure as the motive power. Pressure motive non-electric pumps are a form of the non-electric pump (PMPs).
A plant typically has a separate area with various components required for steam generation, such as a boiler, condensate holding or deaerator (DA) tank, boiler feed pump, water treatment, and so on. Condensate from the holding tank is returned to the boiler through the boiler feed pump, which is operated by the boiler control system.
Pressure Motive Pumps (PMPs) are non-electric pumps that use steam pressure as the motive force to return condensate to the boiler room. PMPs are available as stand-alone systems with a pump tank, internal operating mechanism, and a collection of inlet and outlet check valves, or as a bundled system with a vented receiver tank (for collecting condensate) installed on a standard foundation.
How do you keep a condensate return pump in good working order?
8 Steps to Cleaning a Condensate Return Pump
When a Condensate Return Pump Fails, What Happens? The failure of your air conditioner to turn on is the most common sign of a condensate return pump problem. To prevent the pump’s water tank from overflowing, the AC is turned off. It’s possible that your condensate pump needs to be fixed, washed, or replaced if it’s not working properly.
- Check for water in the condensate return pump.
- Switch off the power at the source.
- Attach the PVC tubing to the reservoir and disconnect it.
- Remove the condensate return pump and position it somewhere safe to operate.
- Rinse the tank.
- Remove any clogs.
- Disconnect the drain lines and reconnect them.